Document 50GN67jLLxEnz32wn4YEj4o2V

UNITED STATES ENVIRONM ENTAL PROTECTION AG EN CY REGION V 230 SOUTH DEARBORN ST CHICAGO, ILLINOIS 60604 August 18, 1981 R E P LY TO ATTENTION Of* 5AHMD Mr. Aliens R. Winklhofer Eastern District Office 25089 Center Ridge Road West Lake, Ohio 44145 Dear Mr. Winklhofer: For more than a decade U.S. Environmental Protection Agency (EPA) has been working to assess and correct pollution in the Great Lakes area. Our Region V office has played a lead role in coordinating these efforts with those of Canada. Considerable progress has been made during this time, but the task is not yet complete. While some of the more obvious types of pollution were being immediately addressed, new toxicant problems were being detected. One of these problems deals with the presence of 2,3,7,8tetrachlorod.ibenzo-p-dioxin (2,3,7,8-TCDD) in the environment. The attached document has been prepared by EPA to summarize information on 2,3,7,8-TCDD related studies which have been conducted in the Great Lakes region. The purpose is to compile in one place information and data which have been generated in several laboratories in the United States and Canada over the past few years. This working paper provides a current data base which should be useful to the public and governmental officials in both countries. Although the geographic coverage and the number of sample analyses presented in this report are limited and additional data are currently being generated, the report indicates varying levels of dioxin contamination in areas of the Great Lakes basin. The implications of these data on the consumption of dioxin contaminated fish are currently undergoing review by various government agencies in the United Spates and Canada. Attachment X, A REPORT ON POLYCHLORINATED DIBENZO-P-OIOXINS (PCDDs) AND POLYCHLORINATED DIBENZOFURANS (PCDFs): A SUMMARY OF STUDIES CONDUCTED IN THE GREAT LAKES AREA U.S. ENVIRONMENTAL PROTECTION AGENCY REGION V CHICAGO, ILLINOIS Ju ly 1981 TABLE OF CONTENTS List of Tables............ ii I. Introduct ion..................... ........... .................... 1 II* Sources of Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in Commercial Products................ 2 III. Sources of PCDDs and PCDFs from Pyrolysis, Photolysis, and Combustion Processes...... ................. .............. .. 2 IV. Studies Involving PCDDs and PCDFs Conducted in the Great Lakes Area................................. 10 V. Current Government Activity on PCDDs and PCDFs............ .. 24- References........................................................... 25 LIST OF TABLES Table 1 - Findings on PCODs and PCOFs in Fly Ash and Other Combust ion Sources 6 Table- 2 - Chlorinated Dioxin Content of Particulate Matter From a Rotary Kiln Incinerator............................ 7 Table 3 - Chlorinated Dioxins in Rotary Kiln Incinerator Scrubber Water.......... 8 Table 4 - Chlorinated Dioxins in Soils and Dusts.................... 9 Table 5 - Results of 2,3,7,8-Tetrachlorodibenzo-p^dioxin (TCDD) Fish Monitoring Program Conducted by the U.S. EPA in Michigan during 1978.................-........ 14, 15, 16 Table 6 - Residues of Dibenzofurans and Dibenzo-p-dioxins in Composite Samples of Fish and Gulls from Different Sites on the Great Lakes.......................... . 21, 22 Table 7 - Samples Analyzed from Crete Metals, Crete, IL.......... .. 24 LIST OF FIGURES Figure 1 - Saginaw River Basin................... 17 Figure 2 - Dioxin in Gull Eggs...................................... 19 -1- I. Introduction In the last several years, concern over the environmental and public health effects from the use of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and Silvex, plant herbicides, has increased. Chemical products containing 2,4,5-T have been shown to contain a highly toxic trace contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), which is considered to be the most toxic of the 22 possible isomeric forms of TCOD. On February 28, 1979, an emergency suspension was imposed on certain uses of 2,4,5-T and Silvex based on extensive animal data showing that exposure to 2,4,5-T, Silvex and/or 2,3,7,8-TCDD resulted in fetotoxic, teratogenic, and carcinogenic effects and on selected epidemiological data (1,2).- TCDOs and other chlorinated dioxins, technically known as polychlorinated dibenzo-p-dioxins (PCDDs) and related compounds, polychlorinated dibenzofurans (PCDFs) are found in certain commercial products. Those compounds which have a broad range of toxicities, are also receiving considerable attention. Evidence exists that PCDDs and PCDFs may be released to the environment by combustion processes. This report summarizes those studies involving PCDDs and PCDFs in the Great Lakes Area. This report does not address the physical, chemical, and toxicological properties of these compounds. Several exten sive reviews on the properties of PCDDs and PCDFs are available (3,4,5,6). One of these reviews, "Long Term Hazards of Polychlorinated Dibenzodioxins and Polychlorinated Dibenzofurans," by Huff, et al is attached at the end of the report. -2- II. Sources of Polychlorinated dibenzo-p-dioxins (PCDOs) and dibenzofurans (PCDFs) in Commercial (Products A. 2,4,5-T and Si 1vex (phenoxy herbicides) 2,3,7,8-TCDD is formed in the manufacture of 2,4,5-trichlorophenol from 1,2,4,5- tetrachlorobenzene, especially if production temperatures exceed 160C(5). Drums of Agent. Orange, a mixture of 2,4,5-T and 2,4,-D, stored in the USA and in the Pacific prior to 1970 have been reported to have 2,3,7,8-TCDD levels ranging from 0.1 to 47 ppm (7). Only trace levels of other PCDDs and PCDFs were found. In 1978, producers of 2,4,5-T reported that their products contain less than 0.1 ppm of 2,3,7,8-TCDD (5). 1 B. Chlorinated Phenols PCDDs and PCDFs have, been found in tri, tetra, and pentachlorophenols (4,8,9).- The quantities of these compounds and their isomeric forms depend upon the reaction process and conditions. In 1978 concentrations* of 2,3,7,8-TCDU in 2,4,5-trichlorophenol and its sodium salt were found to be less than 0.1 ppm (10). Analyses of PCDDs in commercial grade pentachlorophenols (PCP) produced by various manufacturers during the years 1975 to 1977 found hexa-CDDs (HxCDOs) (non-detectable (N.D.) to 520 ppm), hepta-CDDs (HpCDDs) (125 to 180 ppm) and octa-CDDs (OCDDs) (N.D. to 3600 ppm). No TCDDs were found in commercial PCP. There were several isomeric forms of HxCDD, the major isomers being the 1,2,3,6,8,9; 1,2,3,6,7,8; and 1,2,4,6,7,9. The isomeric forms for HpCDD were 1,2,3,4,6,7,9 and 1,2,3,4,6,7,8(8). PCDFs were also detected in PCP including hexa-CDFs (HxCDFs) (9 to 90 ppm), HpCDFs (70 to 400 ppm) and OCDFs (55 to 260 ppm). C. Other Chemicals PCBs have been shown to contain 1-10 ppm of various PCDFs (11). Hexachloro- phene has been reported to contain traces of TCDDs (4). -3- III. Sources of PCDDs and PCDFs from Pyrolysis, Photolysis and Combustion Processes A* Chlorophenols and Related Compounds The pyrolysis or canbustion of chlorophenols, chiorophenoxy compounds or their derivatives has been shown to produce various PCDDs including TCDDs. The 2,3,7,8 isomer of TCDD has been detected in some experiments although generally as a minor component of the total TCDDs and PCDDs* Studies con ducted on the burning of materials such as grass, leaves or wood chips that have been treated with chlorophenols or related compounds have also demon strated that PCDDs are formed (7,12-16). B. Formation of PCDFs by Pyrolysis 1. The pyrolysis of commercial PCBs (Aroclor 1254 and 1260) at temper atures of 500-60QC has been shown by Buser and his co-workers to yield 30 major and more than 30 minor PCDFs. From 3 to 25% of the pyrolyzed PCB was converted to PCDFs. Above 700C only trace amounts of PCDFs are form ed due to the complete destruction of PCB. The formation of PCDFs was shown to be the result of intermolecular cyclizations of PCB (11). 2. PCDDs and PCDFs are produced from the pyrolysis of tri, tetra, and pentachlorobenzenes in the presence of air. TCDDs have been found in pyrolysates of trichlorobenzene. However, the 2,3,7,8-TCOD isomer was present only as a minor constituent (12). 3. Recently it was reported that soot from the burning of transformer fluids containing 65% PCB and 35% chlorinated benzenes, mainly trichloro benzene and tetrachlorobenzene, contained 3 ppm of 2,3,7,8-TCDD and 273 ppm of 2,3,7,3-TCDF (15). C. Formation of PCDDs by Photolysis Dechlorination of OCDD in pentachlorophenol produces tetra, penta, hexa and hepta chlorinated dioxins (8,17). -4- 0.. PCDDs and PCDFs from Combustion Sources and in SoiT and Dust Samples 1. Total amounts of PCDDs and PCDFs in fly ash from a municipal incinerator in Switzerland were found to be 0.2 ppm and 0.1 ppm respectively. At an industrial heating facility, the fly ash contained 0.6 ppm PCDD and 0.2 ppm of PCDF. Only traces of the more toxic PCOOs (2,3,7,8; 1,2,3,7,8; 1,2,3,6,7,8; 1,2,3,7,8,9) were detected (7). More recent comprehensive studies have shown that PCDDs and PCDFs were present in the fly ash of 35 municipal incinerators in Europe up to 1 ppm amounts (4,14). The for mation of PCDDs and PCDFs are thought to be from the combustion of wastes containing polychlorinated phenates related compounds (15,16). 2. A study released by Dow Chemical in 1978 and published in 1980 (18) reported no 2,3,7,8-TCDD (10 ppb detection level) in fly ash from their oil and coal power plant; however, 38 ppb of other TCDD isomers were found at a detection limit of 20 ppb. Detectable levels of PCDDs were found in samples from fireplaces, automobile and truck mufflers and cigarette smoke. The authors concluded that dioxins have been present since the advent of fire. The results of their*study are presented in Table 1 on page 6. In contrast to the 1978 report, the authors in their 1980 article tempered their remarks by stating that some combustion sources may be sources of airborne and waterborne particulates containing PCDDs. It was theorized that the formation of PCDDs could be the result of a reaction between inorganic chloride and organic material and not due to the condensation of preexisting polychlorinated phenols. The 1980 report also included data on emissions from a rotary kiln incinerator operated by Dow-Chemical and analyses of soils and dusts collected between 1976 and 1978. Particu late matter collected from the rotary kiln incinerator, operated without natural gas and burning solid wastes from the facility, had levels of total TCDD reaching 13,200 ppb (Table 2). Two of the samples collected had levels of the 2,3,7,8-isomer greater than all other TCDD isomers. No TCDO emissions were noted when the facility was operated with natural gas. Other PCOOs were found to be substantially reduced (>95%). Analyses were also performed on particulates filtered from the scrubber water (Table 3). Levels of 2,3,7,8-TCDD and other isomers were reduced by 90% when the kiln was operated with natural gas. Results of soil and dust samples reported by the authors are presented in Table 4. The highest levels of PCDOs in soil and dust samples were those collected at the Midland plant and could be from combustion sources and/or chlorophenolic production by Dow Chemical. Evaluation of all data reported has been made by EPA personnel (19,20). 3. The results of Kimble and Gross (21) contrasted with the Dow Chemical findings. At one coal fired power plant they found no TCDO at a detection limit of 1.2 ppt in fly ash. Based upon work in their laboratory Lustenhouwer, et al, (14) have questioned the extraction method used by Kimble and Gross; however, the method was not exactly duplicated (43,44). In addition, the apparently negative results of Kimble and Gross have subsequently been corroborated by EPA from tests on fly ash obtained from seven coal-fired power plants (45). -6TABLE 1 PCDOs and PCDFs In Fly Ash and Other Combustion Sources (Reference #18) Sample Number of sam ples Other isomers Apparent dioxin content, ng/g(ppb)' TCDD 2,3,7,8- Total HCDD HXCOO OCDD Incinerators, power house - Dow powerhouse Dow rotary incinerator stack (pre sent normal oper ation with sup plemental fuel) Dow stationary tar burner stack (nor mal operation with supplemental fuel) U.S. municipal in cinerator (elec trostatic precipi tator)(Nashvill e, TN) European municipal incinerators 1 5 5 1 38(20) N.D. 7.3 N.D.(10) 38(20) N.D.(2) N.D. 0.4 N.D. 7.7 2-20 24 24 1-5 4-100 9,950 1-20 27-160 190-440 14 28 30 30-200 60-130 40-120 Muff1ers Diesel truck muffler 2 0.02 0.003 0.023 0.020 Auto muff1er 4 N.D.-0.004 N.D.-0.004 N.D. -0.008 N.D. 0.100 0.26 0.003-0.01 0.02-0.07 Other sources Home fireplace soot Home electrostatic precipitator Cigarette smoke Charcoal-broiled steak 2 N.D.-0.3 1 0.4(0.4) 2 N.D. 4 N.D. N.D.-0.1 0.6 N.D. N.D. N.D.-0.4 1.0 0.2-3 34 0.7-16 430 N.D. N.D. 0.004-0.008 0.009 N.D. N.D. 0.9-25 1,300 0.02-0.05 0.03(0.03) Where multiple samples were analyzed from similar sources, the range of observed values is shown. 2) N.D. indicates that the signal observed was less than 2.5 times noise. Limits of detection not within these ranges are shown parenthetically after the value reported for sig nals between 2.5 and 10 times noise. 3) Data without supplemental fuel is not included here because this practice has been eliminated. i -7- TABLE 2 Chlorinated Oioxin Content of Particulate Matter1 From a Rotary Kiln Incinerator (Reference #18) Fuel! Apparent, dioxins, ng/g (ppb) Sam ple R iF i RiF2 r 2F! R3 F1 Kiln T,SW,G T,SW,G T,SW,G T,SW,G Secondary T Other isomers TCDD 2,3,7,8TCOO HxCDD Without supplemental fuel 1,800 2.8002 13,000 5,000 8,2002 65,000 3,300 110 1,300 12,000 N.D.(260)3 5,600 HpCDD OCDD 110,000 510,000 2,000 37,000 180,000 810,000 3,000 59,000 With supplemental fuel- *3 T,SW,G 0,6 N.D.(8.0) N.D.(2.0) 1.4 H T,SW,G N.D.(7.0) N.D.(5.0) N.D.(1.0) r 5 T,SW,G N.O.(2.0) N.D.(2.0) N.D.(0.5) r6 T,SW,G t .g N.D.(2.0) N.D.(4.0) R7 T,SW,G N.D.(2.0) N.D.(2.0) 5.0 4.0 13.0 4.0 6.0 27.0 110.0 30.0 9.0 15.0 170.0 950.0 1- T, tars; SW, sol id waste; G, gas ; 0, oil. 2. The high results reported for the 2,3,7,8-isomer are probably due to analysis by the nonspecific GC-MS packed-column method. Later results were obtained with a capillary column specific for 2,3,7,8-TCDD. The TCDD results from run 1 (R-) are not comparable to those from runs 2 and 3. 3. Numbers in parentheses are limits of detection. -8TABLE 3 Chlorinated Dioxins in Rotary Kiln Incinerator Scrubber Water (Reference #18) Apparent dioxins, ng/g (ppb) Sample Particulates filtered from scrubber water Without supplemental fuel Other isomers TCDD 300 2,3,7,8TCOO HxCDD HnCDD OCDD 2,200 * 3,400 26,000 42,000 With supplemental fuel 14 32* 200 Filtered scrubber water without supplemental fuel * ** 0.0018(0.01) 0.001*(0.0006) 0.005 970 0.024 1,200 0.026 * The analytical method did not separate 2,3,7,8-TCDO from 11 other isomers. ** Numbers in parenthesis are limits of detection. 9TABLE 4 Chlorinated Dioxins in Soils and Dusts (Reference #18): Apparent dioxin content, ng/g (ppb)l Num ber of sam ples Other isomers TCDD 2,3,7,8TCDD Total TCDD Soil Rural (Gaylord, MI) 5 N.D.2 Urban (Lansing & 5 East Lansing, MI) N.D. Major metropolitan (Chicago, IL) 8 0.005-0.03 Daw Chemical (Midland, MI) 5 0.8-18 0.3-100 1-120 HxCOO HpCDO OCDO N.D. N.D.-0.05 0.03-1.2 0.03-2 N.D.-0.2 0.05-2 0.03-0.3, 0.1-3 0.4-22 7-280 70-3,200 490-20,01 Dust Dow Chemical lab. 6 0.5-2 0.7-3 Midland, Michigan 2 Metropolitan (Detroit, MI) 4 Metropolitan (St. Louis, MO) 1 0.16 0.12 Metropolitan (Chicago, IL) 2 1-4 9-35 140-1,200 0.03-0.04(0.02)3 0.2-0.4 2-4 N.D.-(0.03) N.D.-0.3 0.3-4 650-7,50 20-30 0.1-4 0.3 2 34 210 0.04(0.04) N.D.-0.3 0.6-3 3-8 1. Where multiple samples were analyzed from similar sources, the range of observed values is shown. 2. N.D. = Not Oetectable 3. Value in parentheses indicates detection limit. -10- IV. Studies Involving PCDDs and PCDFs Conducted in the Great Lakes Area A. Dow Chemical Monitoring Study, Midland, Michigan (June, 1978) In June, 1978, Dow Chemical reported results of their monitoring program to the Michigan Department of Natural Resources (MDNR) as requested by that agency (22). The data has been summarized below1. Tittabawassee River Water and Sediment (1976) Ten samples (two water and eight sediment) from the Tittabawassee River and below the plant showed no detectable amounts of TCDDs. The detection limit (DL) for sediments ranged from 10 to 50 ppt. Water samples were analyzed at a DL of 1 ppt. 2. Plant Discharge Stream (1976-1978) Composite and grab samples of wastewater discharge revealed no detectable levels of TCDDs in 13 of 14 samples (DL=5 ppt or less). One sample was found to contain 8 ppt of TCDDs. 3. Bioconcentration Study (1978) Analyses performed on the edible portions of fish flesh from caged trout placed six miles downstream of the plant's effluent for periods of 7,14, and 30 days revealed no detectable level of TCDOs at a DL of 10 to 30 ppt. Five of six fish placed in the tertiary effluent stream for 7 days were found to have TCDOs ranging from 20 to 50 ppt at a DL of 10 to 20 ppt. When analyses were also performed on whole fish, the 30 day trout (downstream) showed TCDDs ranging from 10 to 20 ppt when analyzed at a DL of 5 ppt. The fish collected from the tertiary effluent stream showed higher levels of TCDDs ranging from 50 to 70 ppt at a DL of 20 ppt. Analyses on the 7 day trout (edible and whole fish) caged along the river bottom -11- reveal ed no TCDDs at a DL of 10 to 40 ppt. No TCDDs were detected in analyses performed on the edible portions of fish flesh from unexposed control fish (DL=20 ppt) and those placed in the. river at Dow dam (DL=20 ppt), indicating that TCDDs could be present in the plant's effluent (4)* 4. Native Fish Studies (a) 1976 (Analyses 1978) TCDDs were detected in 4 of 9 catfish samples, edible portions, at levels ranging from 70 to 230 ppt. Three of the four samples in which TCDDs were detected were located downstream of the plant's effluent. OCDDs were found in 8 of 9 fish, collected both upstream and downstream of the discharge. The levels ranged from 40 to 150 ppt. One fish sample was positive for HxCDDs (90 ppt). Detection limits ranged from 10 to 200 ppt. (b) 1977 (Analyses 1978) Fish caught downstream of Dow at Smith's Crossing (Figure 1) in the Tittabawassee River revealed contamination in 9 of 14 fish tested. Analyses were performed on the edible portions of fish flesh. The levels of TCDDs ranged from 20 to 244 ppt. (c) Saginaw Bay 1978 Of three fish collected from Saginaw Bay, one catfish was found to contain 24 ppt TCDDs, at a DL of 10 ppt. The analyses were performed on the edible portions of fish flesh. 5. Chlorophenols Chiorophenols were found in the Dow effluent up to levels of 70 ppb. 2,3,4,6-tetrachlorophenol and pentachlorophenol were present at ppb levels below the dam in sediments of the Tittabawassee River. Chlorophenols were also found in some fish at ppb levels above the discharge point of the plant's wastewater effluent. -12- Based upon these findings, the Michigan Department of Public Health issued an advisory on June 28 1978 against consuming fish caught in the waters of the Tittabawassee and Saginaw Rivers. This health advisory is still in effect at this date (23). B. Dow Chemical Monitoring Study, Midland, Michigan (October, 1978) Results of PCDD sampling indicated the presence of 2,3,7,8-TCDD in 2,4,5-T sludge at 10 ppt and in trichlorophenol scrubber fluid at 20 ppt (24). The 2,4,5-T sludge also contained 11 ppt HxCDDs, 4 ppt HpCDDs, and 43 ppt OCDDs Brine wastes and sludges from 2,4-D processes were negative for PCDDs. C. U.S. EPA TCDD Fish Monitoring Program (December, 1978) In response to Dow's first monitoring report, which indicated incidental contamination of fish from the lower Tittabawassee River, fish were collected and analyzed from the Tittabawassee, Grand and Saginaw Rivers (25). In 26 out of 35 skinless fillet fish samples, detectable levels of 2,3,7,8-TCDD were found and ranged from 4 to 695 ppt. Eleven of these fish samples contained TCDD levels greater than 40 ppt. All but two of these samples were from locations downstream of Midland. Four out of 6 samples collected upstream were found to be negative for 2,3,7,8-TCDD. Data is presented in Table 2 on pages 14 and 15. Analyses of spiked blind controls, which consisted of various known levels of 2,3,7,8-TCDD, indicated that the positive results were within +_ 20% of the values reported. Responding to a request from the Governor of Michigan, the FDA recommended that fish contain ing TCDD (2,3,7,8-TCDD) at a level of more than 100 ppt not be consumed. Where 2,3,7,8-TCDD had been found in fish below 100 ppt, it was recommended that no more than one average size portion of fish be consumed per week (26). -13- D. U.S. EPA-Michigan Monitoring Study of Dow Chemical, Midland, Michigan' (April, 1979) 1 Results of TCDD analysis of samples taken from Dow's 2,4,5-Trichlorophenol Injection well (DL=0.06 ppt), phenol treatment system (DL=82 ppt), plant effluent (DL=Q.0Q2 ppt) and upstream Tittabawassee River (DL=5.0 x 10"5 ppt), were found to be negative. However, the carbon filter concentration system utilized was believed to be unsuitable for concentrating contaminants found in water (27). E. Dow Chemical Study on Fish, April 1979 As part of Dow's study on dioxin the company reported finding the following ranges of dioxins in parts per trillion (ppt) in fish collected from other tributaries of the Saginaw River (28). Flint Fiver Cass River Shiawasse River Number of Samples 6 6 6 Number of Positive Results 5 4 1 TCDDs ND-n HD-104 ND-9 HxCDDs ND-6 ND-n ND HpCDDs ND-5 ND-11 ND OCDOs ND-20 ND-44 ND ND=not detected F. Composite Fish Sample from the Tittabawassee River (December 1980) A single composite whole fish sample of five carp, supplied by the MDNR, (collected downstream of Midland) and analyzed by Columbia National Pesticide Laboratories, yielded positive results for various PCDDs and PCDFs (29). The 2,3,7,8-isomer of TCDD constituted >90% of the TCDDs found (30,31). The results are shown below: Total TCDDs 31 PCDDs 31 HxCDDs 44 HpCDDs 53 PCDDs 14 PCDDs 223 ppt Total TCDFs 37 PCDFs 73 HxCDFs 145 HpCDFs 31 CCDFs 4 PCDFs 290 ppt -14 TABLE S RESULTS OF 2,3,7,8-TETRACHLORODIBENZO-P-DlOXIN (TCOO) FISH MONITORING PROGRAM CONDUCTED BY THE U.S. ENVIRONMENTAL PROTECTION AGENCY IN MICHIGAN DURING 1978 LOCATION Tittabawassee River Tittabawassee Road Freeland Road Smith's Crossing Road Above Dow Dam Dub!in Road FISH SPECIES FISH LENGTH (cm) * TCDD LEVEL CPPt) a Carp Yellow Perch Carp Carp Yellow Perch Channel Catfish Carp Channel Catfish Carp Sucker Sucker Channel Catfish Carp Carp Channel Catfish Yellow Perch Carp 42.2 16.2 11.0b 39.7 40.0 16.8 12.3 50.3 38.0 38.2 23.1 35.6 38.1 30.9 34.6 33.0 38.1 19.3 52.2 * Skinless Fillets 52 20 93 32 10 273 22 695 49 8 21 42 NDC ND 28 ND ND TCDO DETECTION LIMITS (ppt) 8 8 6 4 5 6 n 60 1 4 4 9 5 9 2 4 9 LOCATION Saginaw River Wickes Park Block's Marina Mouth Grand River Jones Road near Eagle Near Ionia Saginaw Bay Lat. 43 40* 16" Long. 83 501 2 V 15TABLE 5 (coni'd) FISH SPECIES FISH LENGTH (cm) * TCDD LEVEL (ppt)a TCDD DETECTION LIMITS (ppt) Carp Yellow Perch Channel Catfish Channel Catfish Carp Channel Catfish Carp Yellow- Perch 46.0 11.9 11.4 69.0 48.5 51.8 46.0 45.0 16.0 16.0 62 ND 105 52 28 30 153 .n Carp Carp Channel Catfish Small mouth Bass Smallmouth Bass Carp Sucker 39.0 39.0 -- 35 38.0 50.8 48.3 20 41 29 7 8 ND ND Sucker Yellow Perch 28.2 31.0 24.2 26.8 * Skinless F ille ts 4 ND 13 11 7 8 4 6 13 4 4 8 6 6 6 2 2 2 3 Location Lake Michigan Off Saugatuck -16TABLE 5 (cont'd) FISH SPECIES Lake Trout FISH LENGTH (cm) 50.8 * TCOD LEVEL (ppt)l TCDO DECTECTION LIMITS (ppt) _ NO 7 a ppt indicates parts per trillion which is equivalent to ng/kg. b signifies composite fish sample, c NO indicates that TCDD was not detected in the fish sample at the corresponding detection limit. * Skinless Fillets FIGURE 1 SAGINAW RIVER BASIN * Approximately 3 river miles upstream from confluence of Chippewa and Ttttabawasseeflivefs -18- G* Canadian Study on Gull Eggs from the Great Lakes Dr. Douglass Hal let of the Canadian Wildlife Service reported finding 2.3.7.8- TCDD in Herring gull eggs, collected in 1980, at 12 different locations within the Great Lakes (32).. The highest levels of 2,3,7,8-TCDD were found in Saginaw Bay eggs (43-90 ppt) Levels in' Lake Ontario eggs were slightly lower and ranged fhom 44-64 ppt. Lower levels (approximately 3-10 ppt) were found in eggs collected at other Great Lakes sites. The 2.3.7.8- TCDD isomer was found to predominate (>90%). These results are graphically presented in Figure 2. There have been no reports of abnor malities in gull chicks or mature birds. Egg samples collected from Lake Ontario in 1971 and preserved until analysis in 1980 had 2,3,7,8-TCDD levels of 800 ppt. It was conjectured that the decrease in 2,3,7,8-TCDD levels since 1971 (Figure 2) might be attributed to the discontinuation of 2,4,5-trichlorophenol production by Hooker Chemical at Niagara Falls, New York in 1971. Confirmational analyses of gull egg samples are now underway in U.S. laboratories. H. Gull Flesh Analyses From the Great Lakes (December 1980) Two flesh samples from gulls in the Saginaw- Bay were recently analyzed by Dr. David Stalling of the Columbia National Fisheries Research Laboratory (30). In the two samples, the 2,3,7,8-TCDD isomer predominated (>90%) and was found at levels of 70 and 160 ppt (31). HxCDDs and OCDDs were also found resulting in a total PCDD level of 186 and 196 ppt. Total PCDFs were found at 117 and 121 ppt with the PnCDFs and HxCDFs being the predominate furans. Figure 2: "Dioxin in Gull Eggs" (Reference 27) -20- I. PCDD and PCDF Analyses on Great Lakes Fish (April 1981) 1. The Columbia National Fisheries Research Laboratory has obtained positive results for TCOOs and TCOFs on composite whole fish samples from the Great Lakes (29). This fish sampling is being conducted under the National Pesticides Monitoring Program. Huron and Ontario fish samples ranged in TCOD concentrations from 33 to 94 ppt. The highest values were reported in fish collected from Saginaw Bay in 1978. Data collected to date is presented in Table 6. Tittabawassee fish data (see E. above) is included for comparison. The predominate (>90%) isomeric form of TCDD discovered has been 2,3,7,8-TCOD (30,31). The majority (>90%) of the other chlorinated dioxins and furans found in fish appear to have the 2,3,7,8 ring positions chlorinated (30,31). Therefore, the potential toxicity of these dioxins and furans may approach that of 2,3,7,8-TCDD (3). Very preliminary data indicates that the isomeric distribution of PCODs and PCDFs in river sediments do not reflect those found in fish (31,33). Differences in , solubilities of PCDDs and PCDFs, absorption or retention of these chemicals could account for the observed difference in distribution (33). 2. The FDA has also reported finding TCDDs in fish from Saginaw Bay. Analyses performed by FDA on edible fillets from 27 fish collected from Saginaw Bay in 1979, determined four to be positive for TCDDs (21 to 45 ppt). FDA recommended that fish having TCDD residues above 100 ppt should not be consumed and even lower levels, down to 50 ppt, consumption should be limited. FDA stated that no adverse health consequences would be anticipated from the moderate consumption of fish containing TCDD residues below 50 ppt (34). TABLE 6 Residues of Dibenzofurans and Dibenzo-p-dioxins in Composite Samples of Fish and Culls From Different Sites'' on the Great Lakes. Residues are in parts-per-trillion and by Number of Chlorine Substitutions(29). Site and Sample Dibenzof urans____________ 4C1 5C1 6C1 7C1 8C1 Total __________ Dibenzo-p-Dioxins__________ 4C1 5C1 6C1 . 7C1 SCI Total Sample Intjex 1 Saginaw Bay, L. Huron Carp 27 44 34 44 Saginaw Bay, L. Huron Herring Gull //I Saginaw Bay, L. Huron Herring Gull 02 16 28 57 17 l 15 50 40 7 Bay Port, L. Huron Carp 5 12 5 6 L. Huron 79-06 (Duplicate analyses) (1) 32 Lake Trout (2) 19 Tlttabawassee Riverbelow Dow Dam Carp 37 27.5 16.3 8.7 29 16 4 73 145 . 31 L. St. Clair 79-12 Walleye 4 4.2 0.7 0.7 L. Erie 79-09 Walleye 17.6 9.2 5.7 5.3 Port Clinton, L. Erie Carp 5524 Saugatuck, L. Michigan 35 41 3 1.4 Lake Trout 4 153 3 121 5 117 1 27 6.3 91 2 70 4 290 2.6 12 2.2 40 1.5 17.5 1.4 87 94 157 122 12 ND 385 160 ND 20 ND 19 199 70 ND 88 ND 28 186 27 21 ND 31 32 i n 81 31 44 53 14 223 ND 9 ND 11 30 5 ND ND ND ND 50 5 GL1 GL2 Gp CL7 CL13 GL9 GL14 GL15 GL3 GL4 TABLE 6 (Continued) Residues of Dibonzofurans and Dibenzo-p-dioxins in Composite Samples of Fish and Gulls From Different Sites on the Great Lakes. Residues are in parts-per-trillion and by Number of Chlorine Substitutions(29). Site and Sample L. MichiBan~79-check Lake Trout Dlbenzofurans 4C1 SCI 6C1 7C1 8C1 Total 33 61 10.4 4.4 2 n o Keweenaw, L. Superior 26 9 2 1 2 40 Bloater Chub Isle Royale, L. Slskiwit, 10 L. Superior Lake Trout 5 ND ND Trace *5 L. Superior 79-02 Lake Trout 19 8, 9 5.4 3.7 2.7 40 1 Roosevelt Beach, L. 19 4 3 3 3 32 Ontario, Brook Trout L. Ontario 79-10 Lake Trout 34 48 29 6 2 119 Dibenzo--p-Dloxlns 4C1 5C1 6Cl 7C1 8C1 Total ND ND ND ND ND t ND ND ND ND ND Trace Trace 33 ND ND ND ND 33 Sample Index No GLJ6 CL5 guo A, GL 12 GL6 GL} 1 -23- 3. The New York State Department of Health is currently screening Lake Ontario fish for contamination. Previous analyses conducted on two fish determined dioxin contamination at 4.6 and 6.5 ppt (35). A potential source of contamination may be from landfills in the Niagara River area where 2,.4,5-trichl orophenoT wastes were dumped (36)-. Sediment samples from streams which drain into the Niagara River have been reported to contain dioxin (37). J. NIEHS Analyses of a Michigan Dairy Herd Tissue Samples and Michigan's Study on Pentachlorophenol Treated Wood (1978-1979) Studies by NIEHS of a dairy herd in Michigan, presumed to be contaminated by contact with PCP treated wood, revealed fat and liver contamination, re spectively, with OCDDs at 7 and 15 ppb; HpCDDs at 6 and 15 ppb; and HxCDUs at 1 and 9 ppb (6). The presence of these contaminants was suspected of causing the illnesses noted in the cattle. Analyses conducted for PCDDs, by the State of Michigan, on the PCP treated wood in barns established the link between the wood and the presence of PCDDs in the cattle samples (38). OCDDs ranged from 289-5000 ppb, HpCDDs from 9-1161 ppb, and HxCDDs from non-detectable to 3.7 ppb in the wood. K. U.S. EPA Assessment of Environmental Contamination in.the Area of Hemlock Michigan (October, 1980) As a result of numerous health complaints involving humans and domestic animals, the U.S. EPA conducted an environmental assessment in 1980 of the Hemlock, Michigan area, located 14 miles south of Midland (39). Citizens were dissatisfied with previous health and environmental studies (negative findings) conducted by county and state agencies. Residents were concerned that potable groundwater had been contaminated from a brine reinjection -24- system operated by Dow Chemical in that area. A study of TCDDs in 40 environmental and biological samples yielded only one positive result at a detection limit of low ppt levels. Several fish, downspout soils, house dusts, a well sediment sample, a septic tank sludge, and sediment samples i from Dow's injection systems were found to be negative for TCDDs at detection levels ranging from 1-43 ppt (40). The one positive sample was a cagedi fish collected from the Tittabawassee River, downstream of Midi and,*which contained 23 ppt TCDDs. L. Crete Metals, Crete, Illinois (December, 1980) TCDDs and TCDFs analyses were performed in 1980 on environmental and bio logical samples as a result of health complaints and the death of several horses near a wire reclamation facility (41). In the reclamation process, insulating and other materials were burned off wires, x-ray plates and transformer cables and other unknown metal containing products. Samples analyzed and results obtained are presented below in Table 7. TABLE 7 TCDDs (ppt) TCDFs (ppt) Stack #2 (Scrapping) Furnace #2 (Scrapping) Soil (on site) Adipose (dead horse) 410 53 21 45 11,600 730 230 165 A variety of isomeric forms of TCDOs and TCDFs were detected, however, the analytical technique utilized could not adequately discriminate and quan tify the isomers. V. Current Government Activity Except for disposal requirements for chlorophenolic wastes containing j 2,3,7,8-TCDD, no other regulations exist for controlling PCDDs and PCDF|s release to the environment (42). The implications of these data on the consumption of dioxin contaminated fish are currently undergoing review by various government agencies in this country and Canada. -25- REFERENCES 1. EPA, "Notice of Intent to Cancel Forestry, Rights of Way, and Pasture Registrations of Pesticide Products Containing 2,4,5-T," February 28, 1979. 2. EPA, Epidemiologic Studies Program, Human Effects Monitoring Branch, "Report of Assessment of a Field Investigation of Six-Year Spontaneous Abortion Rates in Three Oregon Areas in Relation to Forest 2,4,5-T Spray Practices," February 28, 1979. 3. Huff, J.E. et al "Long Term Hazards of Polychlorinated Dibenzodioxins and Polychlorinated Dibenzofurans," Environmental Health Perspectives 36, 221, 1980. 4. Espisito, M.P., et al, "Dioxins", U.S. EPA, Cincinnati, Ohio, 1980. 5. EPA, "Rebuttable Presumption Against Registration and Continued Registration of Pesticide Products Containing 2,4,5-T," Federal Register, Vol. 43, No. 78, April 21, 1978, 6. Joint NIEHS/IARC Working Group, "Long Term Hazards of Polychlorinated Dibenzo dioxins and Polychlorinated Dibenzofurans," June, 1973. 7. Rappe, C., H. R. Buser and H. P. Bosshart, "Polychlorinated Dibenzo-p-Dioxins (PCDDs) and Dibenzo Furans (PCDFs): Occurrence, Formation and Analysis of Environmentally Hazardous Compounds," CIPAC Symposium, Baltimore, Maryland, June, 1979. 8. EPA, Environmental Health Advisory Committee, "Report of the Ad Hoc Study Group on Pentachlorophenol Contaminants," December 29, 1978. 9. Creosote, Inorganic Arsenicals, Pentachlorophenol, EPA, Position Document No. 2/3, January 1981. ^ 10. EPA, "Rebuttable Presumption Against Registration and Continued Registration of Pesticide Products Containing 2,4,5-Trichlorophenol and its Salts," Federal Register, Vol. 43, No. 149, August 2, 1978. 11. 3user, H. R., H. P. Bosshardt and C. Rappe, "Formation of Polychlorinated Dibenzo Furans (PCDFs) from the Pyrolysis of Individual PCB Isomers, Chemosphere, 157, 1979. 12. Buser, H. R., "Formation of Polychlorinated Oibenzo Furans (PCDFs) and Oibenzo-p-Dioxins )PCDDs) from the Pyrolysis of Chlorobenzenes," Chemosphere. 415, 1979. 13. Ahling, B., et al, "Formation of Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans during Combustion of a 2,4,5-T Formulation," Chemosphere, 8, 461, 1979. -26- 14. Lustenhouwer, J., at al, "Chlorinated Dibenzo-p-dioxins and Related Compounds in Incinerator Effluents," Chemosphere. 501, 1980. | 15. Buser, H. R., "Identification of Polychlorinated Dibenzo-p-dioxin Isomers! Found in Fly Ash," Chemosphere. 7_, 165, 1978. ! 16. Rappe, C., et al, "Formation of Polychlorinated Dibenzo-p-dioxins (PCDDs)1 and Polychlorinated Dibenzo-p-furans (PCDFs) by Burning or by Heating Chlorophenates," Chemosphere. _7, 269, 1978.. 17. Nestrick, T. J. , et al, "Indentification of Tetrachlorodibenzo-p-dioxin 1 Isomers at the one ng Level by Photolytic Degradation and Pattern Recogni tion Techniques, Analytical Chemistry. 52, 1865, 1980. 18. Bumb, R. R., et al, "Trace Chemistries of Fire: A Source of Chlorinated 1 Dioxins," Science, 210, 385, 1980. 19. August 8, 1978, communication to Joseph J. Merenda, Director, Assessment Division, 0TE/0TS, "Interim Status Report 3EHQ-0778-0209," from Frank D. Kover, 0TE/0TS. 20. September 6, 1978, communication to Etcyl H. Blair, Dow Chemical, "EPA Document Control No. 8EHQ-0778-0209," from Warren R. Muir, 0TS, EPA. 21. Kimble, B. J. and M. C. Gross, "Tetrachlorodibenzo-p-Dioxin Quantification in Stack-Collected Coal Fly Ash," Science. 207, 50, 1980. 22. June 27, 1978, communication to John Hesse, Office of Toxic Materials Control, Michigan Department of Natural Resources, from John Gledhill, Dow Chemical. i 23. Forney, J., "Summary of Dioxin Contamination in Michigan," Office of Toxic Materials Control, Michigan Department of Natural Resources, December 9, 1980. i 24. January 15, 1979, communication to Mr. G. Amendola, EPA, EDO, "Results of! October Samples from Dow Midland Plant Production Facilities," from H. B.1 Frodge, Dow Chemical Company. 25. December 20, 1978, communication to K. Bremer, EPA, "Summary of Results for Analyses of Samples of Fish from Michigan," from E. 0. Oswald, ETD, HERL., 26. October 17, 1978, communication to Michigan Governor William G. Milliken from Sherwin Gardner, Acting Commissioner of Food and Drugs. 27. April 9, 1978, communication to Karl Bremer, "Results of Analysis of Environ mental Samples from Michigan for TCDD," from E. 0. Oswald, ETD, HERL. 28. April 12, 1979, communication to John Hesse, Office of Toxic Materials Control, Michigan Department of Natural Resources from John Gledhill, Dow Chemical. 29. Stalling, D., "Residues of Dibenzofurans and Dibenzo-p-dioxins in Composite Samples of Fish and Gulls from Different Sites on the Great Lakes," Presented at the Association of Analytical Chemists, Ottawa, Canada, May 12, 1981. -27- 30. January 12, 1981, communication to David Stalling, Columbia National Fisheries Laboratory, from Milt Clark, Office of Toxic Substances, EPA, Region V. 31. July 1, 1981, communication to Milt Clark, Office of Toxic Substances, EPA, Region V, from David Stalling, Columbia National Fisheries Laboratory. 32. Hallet, D. J. and R. Norstom, "TCDD in Great Lakes Herring Gulls," December 2, 1980 Report of the Canadian Wildlife Service, National Wildlife Service. 33. April 16, 1981, communication to Charles Fink, Connecticut Agriculture Experiment Station, from David Stalling,. Columbia National Fisheries Laboratory. 34. April 20, 1981, communication to Dr. Burton Cardwell, Toxic Substance and Emergency Office, Michigan Department of Agriculture From Alan L. Hoeting, District Director, FDA. 35. April 24, 1979, Press Release, New York Department of Public Health. 36. "Hooker Dumpsites May Pose Dioxin Threat," Chemical Week, 124, 16, 1979. 37. May 2, 1979, Press Release, New York Department of Public Health. 38. August 13, 1978, communication to G. Marsh, Pesticides Branch, EPA Region V, from Thomas 0.. Tiernan, Wright State University. 39. EPA Region V, "Evaluation of Suspected Environmental Contamination of the Hemlock, Michigan Area," September 1980. 40. April 25, 1980, communication to Mike Dellarco, Special Pesticides Review, EPA, from Michael Gross, Department of Chemistry, University of Nebraska. 41. Gross, M . , "Analysis of Tetrachlorodioxin and Tetrachlorodibenzofuran in Three Environmental Samples and One Biological Sample," Department of Chemistry, University of Nebraska, December 12, 1980. 42. EPA, "Storage and Disposal of Waste Material: Prohibition of Disposal of Tetrachlorodibenzo-p-Dioxin," Federal Register, Vol. 45, No. 98, May 19, 1980. 43. August 19, 1980, communication to 0. Hutzinger from B. J. Kimble, Letter Exhibit #1500, EPA, 2,4,5-T/Silvex Cancellation Proceedings, Inre: Dow Chemical Company, et al, FIFRA #415, et al. 44. Testimony of 0. Hutzinger, November 18, 1980, Transcript pages 17,466 - 17,471, EPA, 2,4,5-T/Silvex Cancellation Proceedings, Inre: Dow Chemical Company, et al, FIFRA #415, et al. 45. Harless, R.L. and R. G. Lewis "Quantitative Determination of 2,3,7,8-Tetrachlorodibenzo-p-dioxin by Gas Chromatography and Mass Spectroscopy," October 1980, Letter Exhibit #1501, EPA, 2 ,4,5-T/Silvex Cancellation Proceedings, Inre: Dow Chemical Company, et al, FIFRA #415, et al. Environmental Health. Pempectiven VaL dS, pp. JJt-titi, 1980 Long-Term Hazards of Polychlorinated Dibenzodioxins and Polychlorinated Dibenzofurans* by J. E. Huff,1, J. A. Moore/ R. Saracci/ and L. Tomatis* During January 10-11. 1978 In Lyon, France, a joint National Institute of Environmental Health Sciences/International Agency for Research on Cancer ad hoc Working Group consid ered and discussed the feasibility of coordinating epidemiological studies on the long-term haz ards associated with the chlorinated dibenzo-p-dioxins and chlorinated dibenzofurans ( PCDOs and PCDFs). Nineteen invited scientists from eight countries presented introductory working papers summarizing the most up-to-date and relevant information available from their individ ual programs. This report represents the collective views and scientific opinions of the Working Group. The greater part of this document comprises epidemiological studies related to episodes of human exposure. The review begins with a brief section concerning possible routes of human * exposure, an overview of the pertinent chemical characteristics, and the salient toxicological properties of the structurally siimilar PCDDs/PCDFs. The Working Group report ends with recommendations for future activities. Introduction Human exposure in the workplace can occur when chlorinated dibenzo-p-dioxins (PCDDs) are formed during the production of certain com pounds such as the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), the fungicide pentachloro phenol, and the germicide hexachlorophene (i). The dioxins, impurities/contaminants This report was prepared by the NIEHS/IARC Working Group and the full proceedings were printed in June 1978 as IARC Internal Technical Report 73/001. References cited in this report reflect in general those published prior to June 1973. Participants of the NiEHS/IARC Working Group: A. (J. Ar atila, University of Jyvaskyla, Finland: 0. Axelson, Regional Hospital. Linloping, Sweden (Vice Chairman): H. Sartsch, IARC, Lyon. France; P. J. Baxter. Employment Medical Advi sory Service. London, England; F. Benino, Instituto Nazionale per Io Studio e la Cura dei Tumori, Milano. Italy; L. Bisanti, Uffici Regione, Milano. Italy; R. Frentzel-Beyme, Deutsches Krebsforschungszentrum, Heidelberg, Federal Republic of Germany; A. Hay, University of Leeds, United Kingdom; J. S. Huif. IARC, Lyon, France; L. Jirasek, Universit Kariova FVL, Prague, Czechoslovakia: T. Kuroki, IARC. Lyon, France: G. May, Derbyshire. United Kingdom; R. Montesano, IARC, Lyon, France; J. A. Moore. National Institute of Environmen tal Health Sciences, Research Triangle Park. N.C,, U.S.A^ (Chairman): J. Parizek, WHO, Geneva, Switzerland; G. F. November 1380 associated with these end-products, result most often from treatment of chlorinated benzenes at elevated temperature and pressure under alkaline conditions. Via the widespread use of these com mercial products (i, 2) the general population may also become exposed. In recent years, out-of-control chemical reac tions during the production of 2,4,5-trichlorophenol have proceeded to the explosive Peruzzo, Uffici Regione, Seveso, Milano. Italy; F. Pocchiari. Istituto Superiore di SanitO, Rome. Italy; A. Poland. University of Wisconsin Medical School, Madison, Wise., UJ3.A.;C. Rappe, University of lime!, timed, Sweden: V. Riinimaki, Institute of Occupational Health. Helsinki, Finland: R. 'Saracci, IARC, Lyon, France; I. J. Selikoff, Mount Sinai School of Medicine, New York, N. Y.. tiJS.A.; R. R. Suskind. Kettering Laboratory, University of Cincinnati Medical Center, Cincinnati, Ohio U.S.A.; L. Tomatis. IARC, Lyon. France: J. G. Vos, Rijks Instituut voor de Volksgesondheid, Bilthoven, The Netherlands; N. Wald, University of Oxford. Oxford. United Kingdom; J, Wilbourn, IARC, Lyon, France. Address reprint requests to J. S. Hull, National Toxicology Program, P.O. Box 1X233, Research Triangle Park. NC 27709. f National Toxicology Program. P.O. Box L2223. Research Triangle Park. N.C.. 27709. 1International Agency for Research on Cancer, 150 Cours Aibert-Thoraas, 69372 Lyon, Cedex 2. France. 221 'J U j j t a g J B ii- g a g i " i w u f t i ' i " I ' ^ i stage thereby exposing persons to toxic levels of PCDDs. From certain of these accidents, more over, not only did those occupationally involved receive dangerous exposure but also those in habiting the surrounding areas received uncom mon risk. The structurally-related chlorinated dibenzofurans (PCDFs) are contaminants found in somepolychlorinated biphenyl compounds: Aroclor, Clophen, Phenoclor ('). These impurities are more toxic and represent a greater environmental hazard than the. com pounds they contaminate (1, 3-9). For instance, 2,3,7,8-tetra-CPD has been recently found in beef fa t from cattle grazed on 2,4,5-T-treated rangeland and in breast milk from women living in areas where 2,4,5-T is used on rangeland or in for est areas (10). Various investigators (11-14) have also discovered PCDDs and PCDFs in fly ash and flue gas from municipal incinerators, and in dust from fungicide-treated wood (15). Chemical Aspects The PCDDs and PCDFs are two series of tri cyclic aromatic compounds which exhibit similar chemical and physical properties {1, 3, 4). The basic two-dimensional structures (I, II) have eight possible points of chemical addition. From the monochloro to the octachloro derivatives, a va riety of positional isomers are possible: 75 PCDDs and 135 PCDFs (Table 1). The extreme toxic potency of some of these compounds, as well as the large number of poten tial isomers, warrant analytical methods exhib iting high sensitivity and specificity to monitor the environment. A desirable detection limit of one part per trillion (ppt, 1 picogram/gram sample) is being reached with current methodol ogy. Essential requirements included efficient clean-up, good separation and selectivity, ultra sensitive quantification, and validation (iff, 17). Toxicological Aspects Animals The prototype and most extensively studied iso mer of the PCDDs and PCDFs is the 2,3,7,3-tetrachlorodibenzo-p-dioxin (2,3,7,8-tetra-CDD), perhaps the most potent man-made toxin pres ently known. The comparative oral lethal dose val ues for various PCDDs in mice and guinea pigs (Table 2) show clearly that the 2,3,7,8-tetra-CDD and the 1,2,3,7,8-penta-CDD isomers are the most toxic (13). 99 Toxic effects induced by PCDDs and PCDFs vary quantitatively and qualitatively among dif ferent species; however, within a single species the untoward consequences are markedly similar for all PCDDs and PCDFs that have been studied. For example, the toxic effects induced by 2,3,7,8tetra-CDD which are most often observed in mice, guinea-pigs, and monkeys, are illustrated in Table 3 (20). In a brief report, daily oral intake. (12-til days) of <1 /ig/kg body weight 2,3,7,8-tetra-CDD was stated as being lethal to young male rhesus monkeys (21), whereas McConnell et al. (22) re ported an LDm, in female rhesus monkeys as <70 Hg/k g body weight. A preliminary report on 2,3,7.8-tetra-CDF con cerning the toxicity of PCDFs (23), and a report on PCDFs (24) have been published. The toxic syndrome produced by PCDDs and PCDFs may be divided into seven categories: Chioracne. 2,3,7,8-Tetra-CDD and the triPCDF and tetra-PCDF were found to be active skin irritants and to induce acneform lesions in the skin of rabbit ears (25). Classical chioracne is a hallmark of PCDD ex posure in humans and an analogous hyper keratosis and the modulation of sebaceous struc tures to keratin cysts have been observed in monkeys, rabbits, and hairless mice. Chioracne or acneform dermatitis is a common occupational derm atitis characterized by com edones, keratin cysts, pustules, papules, and ab scesses. In 1957, Kimmig and Schulz (28) found that 2,3,7,8-tetra-CDD was the agent responsible for causing occupational chioracne in employees of chlorophenol-producing factories. Further, in 1971 PCDDs were implicated as causing chioracne in male workers in a plant producing 2,4-D and 2,4,5-T (27, 28). Chioracne may appear weeks or months after the initial exposure to PCDDs and PCDFs. H e p a to x ic ity . The degree of hepatic in volvement appears to be dose-dependent, and the severity of the changes produced varies between species (29). Hepatic necrosis produced by 2,3,7,8tetra-CDD is probably a contributing cause of death in rats and rabbits, while hepatic necrosis and liver insufficiency are less extensive in mice and are minimal in comparison in guinea pigs and monkeys (22, 30-37). Hepatic porphyrin accumu lation has been observed in mice, rats, and chick ens. Hypop/asia o f th e L y m p h o id Tis sues. Particularly involved are the cortical ceils of the thymus and this hypoplasia has been ob served in mice, rats, guinea-pigs, and monkeys. The most significant findings in both mice and Environmental Health Perspectives . \ J4 4 - : rL. i? ? 3 4 04 CIx I / 6 O Cly II guinea-pigs treated with sublethal doses of 2.3.7.8- letra-CDD were in the lymphoid system, resulting in suppression of cell-mediated immu nity, particularly in young animals (*6, 38). Low levels of 2,3,7,8-tetra-CDD that did not produce overt clinical or pathological changes 3till reduced host defences: 1 jig/kg bw given orally once weekly for 4 weeks to mice before infection with Salmonella increased mortality and decreased the time from infection to death {39). The increased mortality may be caused by the endotoxin content of these gram negative bacteria, since 2,3,7,8tetra-CDD markedly increases the susceptibility of mice to endotoxin (lipopolysaccharide of Esche ric h ia coli) UO). Treatment of female mice and rats with 2,3,7,8-tetra-CDD during the latter half of gestation and in the postnatal period resulted in a severe depletion of lymphocytes in the thymic cortex of the offspring (41), Cellular immunity was impaired. Hematological changes in mice, rats, and guinea pigs treated with 2,3,7,8-tetra-CDD in clude lymphopenia and thrombocytopenia (45, 43) ; manifest also is an increased susceptibility to infection concomitant with the suppression of cell-mediated immunity. For 9 months, female rhesus monkeys received a diet containing 500 ppt 2.3.7.8- tetra-CDD; within 6 months, the monkeys became anemic and after 9 months pancytopnie Table 1. Possible number of isomers for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans. Chlorine atoms PCDD isomers- PCDF isomers4 1 2 3 4 5 6 7 3 Total 2 10 14 22 14 10 2 1 75 4 16 23 33 23 16 4 1 135 ` Chlorinated dibenzo-dioxins: empirical formula C12HT_o C I^O * molecular weight ranges, 218-460. h Chlorinated dibenzofurans: empirical formula, C iaH ^ CI^G; molecular weight ranges, 2Q2-144. November 1.980 (44) . The marked thrombocytopenia was associ ated with widespread hemorrhage. Death oc curred in five of the eight monkeys between months 7 and 12 of the experiment at total ex posure levels of 2,3,7,8-tetra-CDD of 2-3 /ig/kg body w eight At autopsy, in addition to extensive hemorrhage, there was a distinct hypoceilularity of the bone marrow and lymph nodes. Hyper trophy, hyperplasia, and metaplasia of the epithe lium in the bronchial tree, bile ducts, pancreatic ducts, salivary-gland ducts, and palpebral conjunctivae were observed. Squamous metaplasia and keratin ization of the sebaceous glands and hair follicles were present in the skin. Death was attributed to complications from the severe pan cytopenia (44). Genera/ Debilitation and Wasting. Animals that receive a toxic or lethal dose of PCDDs or PCDFs exhibit a chronic and progressive weight loss with parallel mobilization of peripheral fat, increased serum triglyceride levels, and develop ment of a fatty liver. Death due to PCDDs or PCDFs intoxication is delayed, as exemplified by an elapsed time period of 6 to 8 weeks following administration of a lethal dose and eventual death {18,22, 44). E m b r y o to x ic ity a n d T e r a to g e n ic ity o f 2,3,7,8tetra-C D D . In repeated or single doses of 2,3,7,8-tetra-CDD to mice, as little as 1-10 .ug/kg cause increased frequencies of cleft palate and kidney abnormalities (45-48) (see Table 4). In rats, embryo-lethal effects occur under experi mental conditions (45, 50), and kidney anomalies (45) , intestinal hemorrhages, and general edema can be produced in the fetuses (Ji). Few follow up studies of the effects of prenatal exposure on postnatal functions have been published. In mice, fetal kidney abnormalities caused by 2,3,7,8-tetraCDD may progress into a hydronephrosis during the postnatal period (53). Chicle Edema Disease. Hydropericardium, as cites, subcutaneous edema, liver necrosis, and death were described in 1957 following the acci dental administration of toxic fats in the feed of broiler chickens (ascites have been observed also in mice) (!). The toxic material was later idenci- 223 m i 4 -ii 1 ? V.3 b h 3 .3 f. a As2* Table 2. Estimuted sinic oral L.D50-30 values of certain polychlorinated dibenzo-p-dioxin isomers,* C hlorine isom er J* 2.3.7 3.7,8 1,3.7.8 t.2.4.7,3 1.231.4.7.8 lA W A 1JU .7A 9 L,3.4.6.7,3 l-N O --3.7,8 1-NH..-3.7.S \-N O -2,3,7 ^ UNH.r iU ,7,3 >300,000 29,444 2 3.1 U 2S 725 70-100" 60-100" >600 >30,000 >30,000 47.5 194.2 G uinea pigs im oie/kg >1,180 120.41 0.006 0.009 3.15 0.185 0.178-0.255 0.153-0-255 >1.400 >90 >99 0.129 0.576 __ >3,000 283.7 337.5 >5,000 825 U250 >1,440 -- -- -- >2,000 >4.800 Mice jum oJe/kg >10 Q8 0.94 >14 2.11 3.19 > 3 .6 7 --. -- -- > 5 .4 > 1 4 .2 * Data from McConnell at al. (IS). The was calculated by the Spearman-Karber method (IS). h Estimated range due to variability in replicates. ficd in commercial oleic and stearic acids produced from inedible tallow recovered from animal hides; trichlorophenols and pentachlorophenols had been used in the curing of the hides. The edema causa tive was termed toxic fat and more specifically chick edema factor and was characterized by xray crystallography as 1,2,3,7,8,9-hexa-CDD {53). 2,3,7,8-Tetra-CDD, hexa-CDD, and octa-CDD have been also identified in several commercial fatty acids {51). Daily doses of 10 or 100 fig hexaCDD/kg bw, or of 1 or 10 fig 2,3,7,8-tetra-CDD/kg bw, produced a positive response in the chick edema bioassay; 0.5% octa-CDD in the diet had no effect (5). Similar edematous effects were ob served in rats, pigs, dogs, and monkeys, but not in Table 3. Summary of the toxic effects of 3.7,3tetrachlorodibenzo-p-dioxin.* Thymus involution Spleen reduction (white pulp) Bone marrow hypoplasia Liver megalocytosis/generation Bile duct hyperplasia Testicular degeneration Renal pelvis hyperplasia Urinary bladder hyperplasia Adrenal cortical atrophy (io/ia g i o m . e 7 v.losa) Hemorrhage Intestinal Adrenal Anrilea Cutaneous lesions Mice +++ + -- +-M- +-t- -- -- -* - Guinea Monkeys Pga (female) +-M- + -H- - +-W- ++ + -- -MH- NA + -- -- --+ - *M*+ * Data from Moore {20). guinea pigs (55). Decreased serum albumin may be associated with the edema; edema has been also shown to occur in chicks dosed orally with 2.3.7.8- tetra-CDF (55). . O th er E ffects, la one or more species of labo ratory animals, bone marrow hypoplasia, testicu lar degeneration, renal pelvis and urinary bladder hyperplasia, and hemorrhage in the intestines and adrenals have been observed. E n z y m e In d u c tio n . 2,3,7,8-Tetra-CDD and other halogenated dibenzo-p-dioxins and dibenzofurans stimulate a number of enzyme activities, most notably in the liver (i). 2,3,7,8-Tetra-CDD is a potent inducer of hepatic and renal microsomal drug metabolizing enzymes {57-6$). Intoxication with 2,3,7,8<etra-CDD results in a marked in crease in the cellular smooth endoplasmic reticu lum content of hepatic and-renal cells {60,69). 2.3.7.8- Tetra-CDD can simultaneously activate and suppress certain microsome-associated for eign-compound and steroid-hormone-metabo lizing enzyme systems {63) as well as increase the activity of both renal and hepatic giutathione-S transferase (70). 2,3,7,8-Tetra-CDD is the most active of the PCDDs in inducing hepatic S-aminolevulmic acid (ALA) synthetase and aryl hydrocarbon hydroxy lase (AHH) in chick embryo liver preparations (71, 72). The PCDDs that induce ALA synthetase in chick embryo have two common properties: (1) halogen atoms occupy at least three of the four ring positions (2,3,7,8), and (2) at least one free, nonhalogenated carbon atom is unoccupied (71). The available toxicological data (35) indicate that those PCDDs that are lethal at low doses, terato genic, or produce acne also induce ALA synthe- 224 Environmental Health Perspectives Tabled. Evaluation of reported embryotoxic and teratogenic effects induced by !L3.7.3-tetrachlorodibenzo-p-dioxins in ruta and mice* Dose, jig/kg Species Rat Mouse Strain CD CD-I DBA/2J C57BL/6J NMRI Embryotoxic/ teratogenic effect Intestinal hemorrhage Kidney abnormality Cleft palate Kidney abnormality Cleft palate Kidney abnormality Cleft palate Kidney abnormality Cleft palate Lowest Tested* 0.125 0.5 l? 3 1 3 3 3 3 3 9 15 5 EDwe 0.57 >1 >3 1-3 >3 >3 >3 <3 6.5 <3 40 15- Period of dosing, days 6-15 6-15 6-15 6-15 6-15 6-15 6-15 6-15 9-13 13 U Route Oral S.C. S.C. S.C. S.C. S.C. S.C. S.C. Oral Oral Oral Oral Reference (soy US) US) US) US) US) US) US) Us) Us) U7) un Data from Neubert et al. (7). hThe lowest dose with which an embryotoxic or teratogenic effect detectable at birth has been produced is indicated. Since sometimes only one dose level was tested, this does not necessarily represent the lowest dose from which an effect could result. *EDso*dose required to produce an embryotoxic effect in 50% of animals. tase; those PCDDs that are not toxic generally do not induce ALA synthetase. The structure-activ ity relation of PCDDs to induce AHH in chick em bryos was identical to that in inducing ALA syn thetase (71). Mixed-function oxidase enzyme systems of mouse strains "non-responsive'" to other aromatic hydrocarbons were induced by single doses of 2.3.7.8- tetra-CDD, as evidenced by increases in hepatic monooxygenase activities and in concen trations of cytochrome P-448 (73-76). Genetic resistance to induction of AHH by 3-methylcholanthrene in DBA/2J mice was overcome by treatment with 2,3,7,8-tetra-CDD. This result con flicts with the hypothesis that induction of AHH activity is a consequence of the formation of cyto chrome P-448 (77). A component that has a high binding affinity for 2,3,7,8-tetra-CDD was found in mouse liver cytosol (78). 2,3,7,8-Tetra-CDD induces AHH even in `poorly responsive' strains of mice (73), not only in liver but also in lung, kidney, and colon. The DBA/2N strain, which responds only weakly to the sarcomatogenic action of 3-methylcholanthrene, be comes highly susceptible after treatm ent with 2.3.7.8- tetra-CDD (7,80). _2,3,7,8-Tetra-CDD is approximately 30,000 times more potent than 3-methylcholanthrene in inducing AHH activity in rat liver (81). McConnell et al. (itf) reported that the com parative toxicity of 13 PCDDs in mice and guinea-pigs (see Table 2) supports the idea that the relative potency (or rank order) of a congener to produce one toxic response is a good indicator of its relative potency (or rank order) to produce other toxic manifestations. H ep a tic C yto so l Binding Protein. A macromolecular binding species has been characterized in the hepatic cytosol fraction of mouse and rat liver which has the in vitro binding properties predicted for the receptor for the induction of AHH activity based on the in vivo biology (78): namely, (1) 3H-2,3,7,S-tetra-CDD binds to this cytosol protein reversibly with a high affinity (K 0.27 nM ) comparable to the EDW for hepatic AHH induction ('EDm in mice = 1 amole/kg); (2) the binding affinity of halogenated dibenzo-p-dioxins and dibenzofurans for this protein in m tro corresponds to their potency to induce hepatic AHH activity in the chicken embryo: and (3) other compounds, such as the polycyclic aromatic hydrocarbons, which induce AHH activity and cytochrome P,-450 also compete for this cytosolic binding protein, but compounds which induce other types of microsomal monooxygenase activi ties (e.g., phnobarbital) and steroids fail to bind. Thus, this cytosolic binding protein may be the re ceptor for the induction of AHH activity. Structure-Activity Reiafions. The pathologic effects produced by the toxic PCDD and PCDF isomers are similar to those of 2,3,7,8-tetra-CDD for a given species, differing only in the intensity of the toxic effect produced by a given isomer. The toxic PCDDs have chlorine atoms in at least three of the four lateral ring positions (2,3,7, and 8) with at least one unsubstituted ring position (the octa-CDD is comparatively inactive). To the extent that the toxicity has been determined, a November 1980 225 1 '} "i d3! 4 * i 1 \ 1 ,ri t "1 '5 * * 3j *T * .*J1 .imilar .structure-toxicity relation has been oh- .,,rv.-il for the PCD Fa. The .structure-activity relation established for IVIXJs anti PCDFs for the induction of hepatic aryl hvilrocarbon hydroxylase (AHH) activity uni for binding to the hepatic cytosol binding has been extended to other classes of chlorinated aromatic compounds. 3,4,3'4'-Tetraehlnrtnizoxybcnzene (TCAOB) and 3,4,3',4'-tet- rachloroazobonzene (TCAB) are potent acnegens formed as trace contaminants in the synthesis of :i.-l-dichloroaniline or herbicides based on this cornpound (82). At high doses in animals, TCAB is reported to produce thymic involution and liver damage similar to 2,3,7,3-tetra-CDD (83). Both Ti'AOM and TCAB are potent inducers of hepatic AllII activity and bind to the hepatic cytosol binding protein with a high affinity. Congeners such as 3,5,3'5'-tetrachIoroazoxybenzene and ;i.f).:i',:V-tetrachioroazobenzene fail to induce AHH activity, fail to bind to the hepatic cytosol species, and fail to produce chloracne. Of 16 halogenated biphenyl compounds tested, only 3,4,3'4'-tetrachloro-, 3,4,5,3'4o'-hexachloroand I^.o.SM'S'-hexabromobiphenyls induced hepatic AHH activity and bound to the hepatic cytosol binding species (34). The 3,4,3'4'-tetrachlornbiphenyl has been reported to produce chlor acne. McKinney et al. (55) found that of five hexachlorobiphenyls te ste d in chickens, 3,4,5,3'4'5'-hexachlorobiphenyl was by far the most toxic, and the only one that induced signifi cant chick edema and involution of the thymus. rh a r m a c o k in e tic s . In the rat, following acute or chronic administration, 2,3,7,3-tetra-CDD is ac cumulated primarily in the liver and to a lesser extent in the fat, and is largely eliminated unme- tabolized in the feces with a whole body half-life of about 3 weeks. Some pharmacokinetic experi ments suggest the formation of a polar metabo lite appearing in the urine, but direct attempts to demonstrate metabolism with hepatic microsomes in vitro have been negative (1). .Mutagenicity. Only four dioxin isomers have been evaluated for mutagenicity: the 2,7-di-, 2,3,7.8-tetra, and octa-CDDs as well as the unsubstituted dihenzo-p-dioxin (35). 2,3,7,8-Tetra-CDD increased the reversion fre quency to streptomycin independence in Esche richia coLi Sd-4. In S a lm o n ella ty p h im u r iu m ,, frameshift mutations in strain TA1532. but not biwe substitutions in strain TA1530, were induced by toxic concentrations of 2,3,7,3-tetra-CDD (35). tn plate assays, the response was positive with S. im u riu m TAI532, doubtful with TA1531 and TA1534, and negative with G46 and TA1530 (37). 226 McCann (83) tested 2,3,7,3-tetra-CDD in S. ty p h im u r iu m , both with and without metabolic acti vation, using a spot-test and the standard' plate test with strains TA1532, 7A1535, TA1537, and TA1538; all these tests were negative. Octa-CDD was nonmutagen ic in S. ty p h im u r iu m strains G46, TA1530, and TA1531, and doubt ful results were obtained with strains TA1532 and TA1534 (37). Metabolic activation systems were not included in any of these microbiological as says. Inhibition of mitosis and chromosomal abnor malities (dicentric bridges and chromatin fusion with formation of multinuclei or a single large nucleus) were observed in endosperm cells of the African blood lily (H a e m a n th u s K a th e r in a e Baker) treated with 2,3,7,3-tetra-CDD in the presence or absence of 2,4,5-T (39). No chromosomal aberrations were observed in bone marrow cells of male rats treated with 2,7di-CDD, 2,3,7,8-tetra-CDD, or dibenzo-p-dioxin by oral intubation, with 2,3,7,3-tetra-CDD by ,intraperitoneal injection or orally (.90). However, when Osborne Mendel rats of both sexes were treated twice weekly for 13 weeks with 2,3,7,8-tetra-CDD, a significant but weak increase in the number of chromosome aberrations in bone marrow cells was reported (91). 2,3,7,8-Tetra-CDD did not induce dominant le thal mutations in Wistar rats after oral adminis tration to males for 7 days (51). C a rcin o g en icity. Two reports indicate; that chronic administration of low levels of 2,3,7,3tetra-CDD' to rats is associated with an increased incidence of neoplasia (1, 92, 93). Groups of 10 male Sprague-Dawley rats were fed a diet containing 2,3,7,3-tetra-CDD for 78 weeks in the following amounts (figures in paren theses are approximate weekly doses): 0, 1 ppt (0,0003 p g /k g body weight) 5 ppt (0.001 p g / k g ) , 50 ppt (0.01 p g /k g ) , 500 ppt (0.1 p g /k g ) , 1 ppb (0.4 p g /k g ) , 5 ppb (2.0 p g /k g ) , 50 ppb (24 #igi/kg), 500 ppb (240 /ig/kg), and 1000 ppb (500 ,ug/kg). The three highest dose levels (50, 500, and! 1000 ppb) were toxic and killed all animals by the fourth week. Of the six remaining test groups, the overall incidence of neoplasms was 23/60 (38%); none occurred in the 1 ppt group. In the 5 ppt group, 5/10 animals had 6 neoplasms [earduct carcinoma, lymphocytic leukemia, adeno carcinoma, malignant histocytoma (with rrietastases), angiosarcoma, Leydig-cell adenoma];; the following groups also showed neoplasms: 50 ppt, three observed in 3/10; 500 ppt, four 4/10; 1, ppb, five observed in 4/10; 5 ppb, ten observed in 7/10. Neoplasms were not observed in the controls (92). Environmental Health Perspectives 4 H J . -J t .-3 . .3 Vi Groups of 100 Sprague-Dawiev rats (50 maiea and 50 females) received for two years diets con taining 0, 22, 210, and 22,000 ppt, equivalent to 0.0, 0.001. 0.01, and 0.1 fig 2.3,7,3-tetra-CD D /kg/ day. Continuous ingestion of 0.001 /xg/kg/day did not cause any chemically related changes in tumor incidence or toxicity; feeding with 0.01 jig/kg/day induced an increased incidence (p < 0.05) of he patocellular hyperplastic nodules (female: 18/50 versus 8/86 controls), of focal alveolar hyper plasia in the lungs, and of urinary excretion of porphyrins (female). Dietary intake of 0.1 fig /kg/ day caused an increased incidence (p < 0.05) of hepatocellular carcinomas (female: 11/49 versus 1/86) and squamous-cell carcinomas of the lung (female: 7/49 versus 0/86), of the hard palate/ nasal turbinates (male: 4/50 versus 0/85: female: 4/49 versus 0/86), and of the tongue (male: 3/50 versus 0/85). Further increased were adenoma of the adrenal cortex (male) and hepatocellular hy perplastic nodules (female). At this dose, certain age-related lesions were reduced (males: acinar adenoma of the pancreas; females: granulosal cell neoplasm of the ovary, benign and malignant tu mors of the mammary gland, pituitary adenoma, and benign tumors of the uterus). Also, chronic administration of 2,3,7,3-tetra-CDD caused mul tiple toxicologic effects, including increased mor tality, decreased body weight gain, slight depres sion of certain hematologic parameters, increased urinary excretion of porphyrins and 5-aminolevuiinic acid, increased serum levels of alkaline phosphatase, glutamyl transferase and serum glu tamic pyruvic transaminase, and morphologic changes primarily of the hepatic, lymphoid, res piratory, and vascular tissues of the body (93). These two reports show that chronic adminis tration of 2.3,7,8-tetra CDD causes an increased incidence of neoplasms, but not whether 2,3,7,3tetra-CDD acts as an initiator or promoter. This consideration is particularly important because unequivocal evidence is lacking that 2,3,7,3-tetraCDD is a mutagen or is metabolized, and no evi dence is available that 2,3,7,8-tetra-CDD and/or metabolite (s) bind covalently to macromolecules. As summarized in Table 5, at least 24 long-term carcinogenicity studies on mice and rats are in progress ($4). Humans T o x ic E ffe c ts in H u n ta n s. Toxicity due to 2,3,7,8-tetra-CDD has been reported after occupa tional exposure during the industrial synthesis of 2,4,5-trichlorophenol (TCP) and 2,4,5-T, after ex posure in factories and in the surrounding envi ronment due to accidents occurring during the November 1980 synthesis of TCP, and after exposure to herbi cides and other materials containing 2,3,7,3-tetraCDD. Exposed subjects have been found to de velop a wide variety of lesions and symptoms (Table 6). For instance, a typical exposure victim experiences a number and a variety of clinical signs and symptoms: early exposure symptoms may include a burning sensation of the eyes, nose, and throat followed by headache, dizziness, nau sea, and vomiting. Some days later, severe itch ing, redness, swelling of the face, more marked over the eyelids, nose and lips, may develop. Within the initial weeks after exposure, inflamed nodules as well as pustules appear on the face, forearms, shoulders, neck, and trunk, leading then to comedones and cysts. After a month or two, acneform eruptions emerge and the skin becomes hyperpigmented. At about the same time, aching muscies, mainly in the thighs and chest area, be come manifest and aggravated on exertion. In somnia, extreme irritability, and loss of libido also occur during this stage. Other than the consistently found clinical fea ture of acne, other findings in humans mavinclude: neuromuscular symptoms (weakness and pain with nerve conduction abnormalities), por phyria cutanea tarda, hepatic dysfunctions, hy perlipidemia, cutaneous hyperpigmentation and hirsutism, chronic eye irritation, emotional dis orders, and neuropsychiatric syndromes. Chloracne, one of the most constant and promi nent features of 2,3,7,3-tetra-CDD exposure, has been described as a refractory acne characterized by inclusion cysts, comedones and pustules, with eventual scarring of the skin, more frequently originating on the face and sometimes spreading to other parts of the body. -Many patients also have blepharoconjunctivitis and irritatio n of other mucous membranes. Sometimes the chlor acne is preceded by erythematous and edematous skin lesions. The latent period between exposure and the appearance of dear signs of chloracne ranges from a few weeks to several months (106). An important and unique episode revolves around three scientists who were self-exposed to 2,3,7,8-tetra-CDD: one heated trichlorophenol in an alkaline solution, a second heated potassium tricfalorophenate, and a third worked in the same laboratory as the second and used a diluted solu tion of the synthesized dioxin (107). The first two scientists developed chloracne eight weeks after exposure, whereas the third showed no evidence of the characteristic acneform lesions. Delayed symptoms, probably due to 2,3,7,8-tetra-CDD, de veloped approximately two years later, and the second two scientists showed personality changes wmmm J -i Table 5. Ongoing tong*term carcinogenicity tenting of chlorinated dibenzo-p-diuxins.'*-*1 -3 Number of Compound studies Route Species Dibenzop-dioxin 4 Oral (diet) Mouse, ra t Skia Mouse Mouse (withDMBA)c 2,7-Oi-CDD 4 Oral (diet) Mouse, rat Skin Mouse Mouse (with DMBA)e 2A7-Tri-CDD 3 Oral (gavage) Mouse, ra t Skin Mouse 2A73-Tetra-CD Dd 5 Oral (diet) Rat 1 Oral(gavage) Mouse Oral(gavage) Mouse, rat Skin Mouse 1,2,3,6,73-Hexa-CDD'1 3 Oral (gavage) Mouse, rat Skin Mouse 1 1.2,3,7,3,9-Hexa-CDDM 2 Oral (gavage) Mouse Skin Mouse (with 1.2,3.6,7,3-hexa-CDD) lA3,4,S,7^>Octa-CDD 3 Oral (diet) Mouse, rat Skin Mouse *Data taken from Information Bulletin on the Survey of Chemicals Being Tested for Carcinogenicity, No. 7 ($4). Details of these studies as well as the auchora/institutes are available in this source reference document. I b As of October 1979. carcinogenesis bioassay testing within the National Toxicology Program included unsubstituted dibenzo- p-dioxin (UDD; CAS 262-12-1: NCI Tech. Rept. No. 122). considered not carcinogenic to Osborne-Mendel rats and B6C3FI mice when administered in feed at dose levels of 5 and 10 ppb, and 2,7-dichlorodibenzo-p-dioxin (DCDD; CAS 22357-26-0; NCI Tech. Rept. No. 123). considered not carcinogenic to Osborne-Mendel rats and female B6C3F1 mice but suggestive of a carcinogenic ef fect in male B6C3F1 male mice when fed concentrations of 5 and 10 ppb. Studies are in progress on 1,2,3.6.7.3-hexachlarodibenzo- p-dioxin (HCDD, CAS 57653-65-7) and 2^3,7,S-tetmchlorodibenzo-p-dioxin (TCDD: CAS 1746-01-6) by gavage to Osborne-Mendel rats and B6C3F1 mice and by skin painting on Swiss mice. Testing on 2^,7,3-tetrachlorodibenzofuran (TCDF; CAS 51207-31-9) is to begin in fiscal year 1980. For chemical disposition studies octachlorodibenzo-p-dioxin, 2^J,7,8-tetrachlorodibenzoluran, and the 3tereochemically related 2.4.3',4'-tetrachloroazobenzene are also proposed. n . c DMBA * dimechylbenzanthracene. d The National Toxicology Program has completed and reported the results for the long-term carcinogenesis bioassay studies on | 2^73-tetrachlorodibenzo-p-dioxin and l.2.3.6.7,3-/1.2,3.7,S,9-hexachIorodibenzo-p-dioxins, with the following results. 1 zi 2A7^-tetrachlorodibenzo-p-dioxin--gavage, carcinogenic for Osborne-Mendel rats {increased incidences of follicular-cell thy.roid tumors in males and of liver tumors in females) and carcinogenic for 36C3F1 mice (liver tumors in both sexes and thyroid I tumors in females); dermal, carcinogenic for female Swiss-Webster mice (fibrosarcoma in the integumentary system) and al though not shown carcinogenic for male Swiss-Webster mice, an increase in the same tumor type was observed. Mixture of hexachlorodiben2o-p-dioxins--gavage, carcinogenic for female Osborne-Mendel rats (hepatocellular carcinomas or neoplastic nod ules), carcinogenic for male and female S6C3F1 mice (hepatocellular carcinomas and adenomas), and not demonstrated as carcinogenic for male Osborne-Mendel rats; dermal--not considered carcinogenic for male and female Swiss-Webster mice. (mainly loss of energy and drive); impairment of vision, taste, and muscular coordination; sleep dis turbances; gastrointestinal symptoms; and hir sutism. The first of the three experienced none of these adverse effects. All three exhibited hyper cholesterolemia (>300 mg/lQG ml). Human Exposure to PCDDs and PCDFs Major sources of human exposure to PCDDs and PCDFs include: exposure in the workplace; exposure in factories and in the surrounding envi ronment from industrial accidents: exposure to contaminated materials, wastes, or food in the general environment; and exposure in Vietnam and other intensive herbicide spraying opera tions. (Prior and subsequent to use as a defoliant, 2,4,5-T was used in weed-killing and forest-thin- 228 ning operations in the United States of America and elsewhere). Occupational exposure may occur in manufac turing plants producing chlorinated phenols (tri-, tetra-, and pentachlorophenols), or phenoxy acid herbicides (2,4-0, 2,4,5-T), or PCBs; in factories utilizing these chemicals for the production of other substances (hexachlorophene from 2,4,5-trichlorophenoi) ; in factories manufacturing or re pairing transformers and capacitors or ;having heat exchange or heat hvdrauiic systems contain ing PCBs; and in the use processes of these chem icals under various occupational conditions such as spraying of herbicides, using chlorinated phe nols for a variety of applications (especially wood preservative), sawing, or otherwise processing treated wood, and using hexachlorophene in sani tary occupations. Environmental Health Perspectives to pvp i i Table ($. Toxic eiTecta of 2JL7J-letrnchlon>dibenzo>dioxine in humans. Effects References Dermatological Odorarne Porphyria cutanea tarda Hyperpigmentation and hirsutism Internal Liver damage* Elevated serum hepatic enzyme levels Disorders of fat metabolism Disorders of carbohydrate metabolism Cardiovascular disorders Urinary tract disorders Respiratory disorders Pancreatic disorders Neurological Polyneuropathies (peripheral neuritis) Lower extremity weakness Sensory impairments (sight, hearing, smell, taste) Psychiatric Neurasthenic or depressive syndromes (25, as, 95-108) {27, 101, tOS, 109) {27, 28,107) {27, 95, 98, 101, 102, 10110$, 110) {27, 28, 9$, 101-106,110) (28.101, 107) (28.101, 102,10L 105) (101,102,101, 105) (97,101, 102) (95,101, 102) (101, 102) (101, 102,101, IQS) (28, 95, 99, 101,102, 101, 105,108) (28,101,102, 107,110) (28, 95, 99, 101,102,101, 105,107) * Mild fibrosis, fatty changes, hemofuscin deposition and pa renchymal-cell degeneration were observed in a few cases. The burning of materials impregnated with commercial 2,3,4,6-tetrachIorophenates yielded 150-1000 pg of mixed PCDDs/g chloropnenate. Al though only found as a minor constituent, 2,3,7,3tetra-CDO has been quantified at levels exceeding 10 pg/g chlorophenate (111). Pyrolysis of a technical grade PCB mixture yielded many PCDF isomers; the total yield could be as high as 3-25%. One of the main constituents is 2,3/7,S-tetra-CD F, the most toxic PCDF-isomer. Consequently, uncontrolled burning of PCBs can be an important environmental source of the haz ardous PCDFs, and operations such as welding or soldering electrical equipment containing PCBs, or using casting waxes in foundries, may possibly entail a significant exposure (112). A PCB used ina heat exchange system for two years contained approximately 1.25 ppm of 2,3.7,3-tetra-CDF and a total of 15 ppm of PCDFs (112). Apart from accidents such as the one which oc curred in Seveso in 1976, general environmental exposure may originate from herbicide spraying and waste disposal. An outbreak of PCDDs poisoning in humans, November 1980 horses, and other animals occurred in Missouri in 1971 (97, 111) following the spraying of contami nated oil for dust control in horse arenas. Another possible source of exposure to PCDDs and PCDFs pollution are waste oils, and possibly other waste, when burned both in industrial and municipal incinerators. Under simulated environ mental conditions, the combustion of a standard 2,4,5-T formulation led to formation of small amounts of PCDDs and PCDFs (H5). Buser and Bosshardt (11) quantified the total amount of PCDDs and PCDFs in fly ash from an industrial incinerator heating facility as 0.2 and 0.1 ppm, and in the fly ash from an industrial heating facil ity in Switzerland as 0.6 and 0.3 ppm. More than 30 individual PCDDs can be identified in the fly ash, but the known highly toxic PCDD isomers are only minor constituents (i2). The number of PCDF isomers was larger; but, in this case, the known highly toxic isomers are major constitu ents (12). An additional potential source of human ex posure has been revealed: beef fat taken from cattle grazed on 2,4,5-T-treated rangeland con tained 2,3,7,3-tetra-CDD; of the 11/14 positive samples, the four with the highest levels had 12, 20, 24, and 70 ppt (10). In another study, 3 of 24 samples of beef fat contained 3-4 ppt 2.3,7,8tetra-CDD (U S ). Moreover, in a preliminary re port of an ongoing enlarged study of women liv ing in areas where 2,4,5-T is used on rangeland, 4/ IS breast milk samples each contained approxi mately 1 ppt (10). Workers in wood processing industries are ex posed to wood dust containing preservatives as well as accompanying impurities and degradation products. Wood dust from a saw-mill in which a 2,3,4,6-tetrachlorophenol formulation was used as a fungicide was found to contain 1-10 ppm PCDFs and <0.5 ppm PCDDs (15). In 1968. more than 1200 persons in South-west Japan were intoxicated by consuming a com mercial rice oil contaminated with 1000 ppm PCBs. Nagayama et al. (117) analyzed the rice oil {Yusho oil) and found 5 ppm PCDFs, the major constituents of which were tetra- and pentaCDFs. Buser et al. (113) recently showed that 2,3.7,3-tetra-CDF was the main PCDF in the Yusho oil (0.45 ppm). The high levei of PCDFs was caused by leakage from heat exchangers con taining PCBs contaminated with PCDFs. Workers manufacturing 2,4,5-trichioropnenol (TCP) or 2,4,5-T during normal production opera tions, and/or following explosions taking place in these plants, may have been exposed to a variety of polychlorinated chemicals whose type and 99Q iM lt f quantity depends on the particular chemical proc ing up to 30 mg/kg or more 2,3,7,S-tetra-CDD), esses in use and on the phase of the reaction in may be found in the literature (i. 110,125-127).m which the accident took place. Apparently, for in stance, PCDFs are produced in the earlier stages Exposure Episodes Considered in when mainly tetrachlorobenzene is present and PCDDs are produced nearer the end of the reac- Detail by the N IEH S/IA R C ad h oc tion when primarily trichlorophenol is extant. The Working Group ; concentration of chlorophenols and chloroben zenes, for example, was probably higher in the 1963 episode in The Netherlands, where the acci dent took place at the beginning of the reaction, The text below is a condensed version of the discussions which took place during the two-day NIEHS/IARC ad hoc Working Group Meeting. then in the 1968 episode in the United Kingdom, o r the 1976 accident in Italy, where the explosion Phenoxy Acids Exposure \ -] took place at the end. A thorough description of the reported indus trial accidents and other cases of intoxications ob served in exposed workers is given in the IARC Monograph ( i) . In this present report, only those episodes specifically discussed at length by the NIEHS/IARC ad hoc Working Group will be considered. (A sequential perspective of known, acci dents is given in Table 7). In 1949, the first, reported cases1of industrial poisoning due to the formation of 2,3,7,3-tetraCDD in uncontrolled exothermic reactions oc curred during the m anufacture of 2,4,5-tri- chlorophenoi at a 2,4,5-T-producing factory in Nitro, West Virginia; 288 persons were affected {99, 113). In November 1953, an accident occurred in Ludwigshafen, Federal Republic of Germany, during the manufacture of TCP {101,102,119,120); 53 workers were affected by chloracne. Five cases of chloracne were reported following an industrial accident in an Italian TCP-producing factory {121). In 1963, an accident occurred at the 2,4,5-T-producing factory in The Netherlands; approximately 50 persons were affected by chlor acne {122, 123). In 1966, Dugois et al. (3S) ob served 21 cases of chloracne after an accident in a French factory producing TCP in the Grenoble re gion. In 1968, an accident occurred at the TCPproducing factory at Bolsover, Derbyshire, United Kingdom {103, 106). Within the next 7 months, 79 workers developed chloracne. In 1971, 2,3,7,8-tetra-CDD contaminated waste oil caused an outbreak of poisoning in humans, horses, and other animals {97, 12U). In July 1976, an accident at the TCP-producing factory in Meda, Italy ($) resulted in the contamination of a large, densely populated area, including the towns of Seveso, Cohort studies on herbicide sprayers have been conducted or are being planned In Scandinavian countries. The more advanced of these concerns Swedish railroad workers with exposure to a vari ety of herbicides. These people exhibited a signif icantly increased tumor incidence (apparently dose-dependent) and tumor mortality {129). The excess of tumors was found particularly, among workers with exposure to am itrole (iaminotriazoie), whereas those exposed to phenoxy acids (2,4-D and 2,4,5-T) showed only a slightly in creased excess of cancers. The study was smallsized, comprising 2978 person-years at observa tion in the total cohort and with 18 deaths versus 20.54 expected. The original conclusion from this study was that amitrole exposure may have caused an excess of tumors, whereas there was probably no pertinent increase in tumor incidence associated with exposure to phenoxy acids. The study has been recently reanaiysed using a casecontrol approach, and through stratification on amitrole when considering the effect from phe noxy acids, and vice versa. The results show a pos sible and previously masked tumor-inducing ef fect also from phenoxy acids. Another retrospective cohort mortality study, conducted in Finland on workers of five com panies involved in spraying 2,4-D and 2,4,5-T on brushwood, did not show any increase in mortal ity. During 1955-1971, in the younger group of workers (under 45 years of age), however, four cancer deaths were observed versus less than two expected (no statistically significant difference). A prospective follow-up study for the period 19721976 revealed fewer cancer-related deaths than expected in all age groups. Clinical and anamnes- Meda, Cesano Mademo, and Desio. Key information concerning the effects of hu man exposure to herbicides in Vietnam, especially to the so-called "Agent Orange" (a 50:50 mixture of the rc-butvl esters of 2,4-D and 2,4,5-T, contain- " More than 2,000,000 gallons of Agent Orange remaining from military defoliant operations were destroyed by in cineration on board ship in the Pacific Ocean. L20 miles from Johnston Island. Temperatures not lower than I250C were used. The steel containers were melted (128). 230 Environmental Health Perspectives -- Jggggggl. ILUOiU  tic investigations were also performed showing1a vanced five severe and six slight malforma picture of acute complaints during and following tions were observed in 65 children in the exposed the spraying operations: headache, transient diz group, whereas only one slight malformation was ziness, fatigue, abdominal complaints, skin and observed in the 68 children of the unexposed mucous irritations, and a. few cases of persistent group. This report has been followed by another papulae. study {to be published) of a similar group of chil Interestingly, some samples of 2,4,5-T used in dren of exposed mothers in comparison to chil Finland for spraying operations contained from dren of unexposed mothers. Again a high fre 0.04 to 0.07 ppm 2,3,7,8-tetra-CDD. This may im- quency of malformations among the offspring of ply that the 2,4,5-T produced before 1965 con exposed mothers was reported {133). From these tained lower levels of 2,3,7,8-tetra-CDD impur studies, however, it is not clear if exposure to ities than has been observed subsequently from other hazardous chemicals could be excluded. A 2,4,5-T used elsewhere. However, the analytical retrospective-prospective study is being initiated methods used in the determination of 2.3,7,3- among long-term workers of an United States' : tetra-CDD in the Finnish samples were anti factory which used Seveso-produced 2,4,5-tri- quated in view of the rapid advancements made chlorophenol in the manufacture of hexachloro in analytical methodology and thus a con- phene. However, in the case of hexachlorophene, : firmatory analysis of the samples using modem polychlorinated xanthenes have been also identi i techniques was made by Rappe et al. {130). Five fied as contaminants at a higher level than 2,3,7,8- : samples of 2,4,5-T ester dating from 1962 to 1967 tetra-CDD {133). were analysed for PCDDs and PCDFs; levels of 0.1-0.95 ppm 2,3,7,3-tetra-CDD and 0.1-0.15 ppm Phenoxyacids and Chlorophenols tetra-CDF were found. A second feasibility study was designed and conducted in Finland to determine whether one Exposure in Forestry and in Wood Industry Workers could obtain anamnestic, clinical, hematological, At the Regional Hospital in Umea (Northern and immunological inform ation on Finnish Sweden), Hardell {134.) observed that several pa railway and forestry workers who had been ex tients suffering from mesenchymal tumors re posed for several years to herbicides containing ported occupational or other exposures to phen 2,3,7,8-tetra-CDD. The exposed group consisted of oxyacids. More specifically, 87 mesenchymal 30 men who were control-matched to persons of tumors were diagnosed during the years 1970 the same age coming from the same district with through 1976. Of these cases, 55 were men (more similar job backgrounds and living conditions. Of than expected) and 43 of these 55 men were the tests made, including liver and immuno- known by profession: 19 were either forestry function studies, no differences were observed be workers, farmers and forestry workers, or work tween the exposed and control groups. Although ers in sawmills and papermills where exposure to the population study is too small to permit any chlorophenols is common. Based on the official sta general conclusions as to the potential adverse tistics of Sweden, one can calculate approximat health effects from long-term exposure to phe- ive^ the expected fraction of tumors within these noxy acids, the investigation shows that follow-up trades, resulting in an expectancy of approxi is possible on the health status of persons exposed mately U cases versus the 19 observed. for several years to 2,3,7,8-tetra-CDD-containing The Mount Sinai School of Medicine in New phenoxy acids, and then to compare the exposed York is currently planning a field survey on long group results to carefully matched controls. The term health effects on wood-preservative workers study is in progress. in Arkansas and Oklahoma in the United States of America. Hexachlorophene Exposure An excess of malformations, some severe, has been reported among children whose mothers were employed as nurses in a hospital. The mothers were exposed to hexachlorophene soap during early pregnancy, and the hypothesis of a causal relation between such an exposure and the occurrence of the malformations has been ad- Exposure to 2,3,7,8-Tetra-CDD during Production of 2,4,5-T or Polychlorinated Phenols and Following Industrial Accidents The following cases, as well as others not con sidered at the meeting, have been described in IARC Monographs Volume 15 (I), and only some November 1980 231 nf the previously available information will be ,,'.vrn here. The ongoing epidemiological studies on these cohorts arc summarized in Table 7. As each individual cohort has a relatively small number of person-years, a study has been pro posed in which ail the cohorts would be pooied and the mortality compared to that expected from the national statistics. The first reported cases of industrial poisoning due to the formation of 2,3,7,3-tetra-CDD in un controlled exothermic reactions occurring during the manufacture of TCP were seen in 1949 at a 2.4,5-T-producing factory in Nitro, West Virginia, USA; 228 persons were aifected. These individuals were studied by Suskind and Ashe (i35) and fol lowed up for a period of four years. Symptoms in cluded ehloracne, nausea, vomiting, headaches, se vere muscular aches and pain, fatigue, emotional instability, and intolerance to cold. Laboratory findings showed raised total lipids and raised pro thrombin time. Among those aifected were not only workmen, but also laboratory personnel, medical personnel, and even the. Safety Director who visited the areas of exposure. Several wives who had never visited the plant also developed acne, usually at the same time as their employee husbands. It is important to note that information on the toxicity as well as on the stability (long per sistence and slow degradability) of 2,3,7,8-tetraCDD was not available at the time the first re ports of acute toxicity were observed, and no measures were taken to decontaminate the facto ries and control the residue levels of 2,3,7,8-tetraCDD. In fact, the presence of 2,3,7,8-tetra-CDD or other PCDDs and PCDFs was not even suspected. Workers, therefore, were probably exposed for a considerable time to 2,3,7,3-tetra-CDD following the first observations of acute toxic effects. In November 1953, an accident occurred at a TCP factory in Ludwigshafen, Federal Republic of Germany; 75 workers were exposed to the reac tion products during the accident and the sub sequent cleaning work; most were affected by ehloracne, 42 severely: 21 of the 42 suffered con sequent damage to internal organs or distur bances of the nervous system. The most relevant features were polyneuritis, sensorial impair ments, and liver damage. The son of one of the workers developed ehloracne following contact with his father's work clothes. An additional case of poisoning occurred 5 years later in a worker who was involved in repair work (welding one of the auto-claves) at the contaminated site; sub sequently this worker died with necrotic pan creatitis. J32 All the 75 workers could be traced in a cohort study 25 years later; mortality was compared both with the regional and national mortality and with a control group of workers from the same factory. In the exposed group, 17 deaths were observed (11 to 25 expected depending on the control popu lation); six from cancer (four or less expected), five from cardiovascular diseases (as expected), two from suicides (0.2-0.6 expected), one from liver cirrhosis, one from a urogenital tract dis ease, and two from traffic accidents. Of the six cancer deaths, three were from stom ach cancer and occurred in the age group of 60-69, which is significantly more than expected. This effect was more pronounced when a minimum ob servation period of 10 years was considered, and more so for stomach cancer after a 20-year obser vation period. (Use of a long observation period permits a better estimation of the relation be tween exposure and disease when long "latency" periods are involved, as for cancers). A similar accident occurred at the 2,4,5-T-producing factory in The Netherlands in 1963; 106 men are likely to have been exposed to 2,3,7,3tetra-CDD (and possibly PCDFs) as they were in the building where the accident occurred during the subsequent period, March-July 1963. These workers may be divided into three groups: (A) factory employees (exposed during all phases of the cleaning and reconstruction activities), 44 men; (B) clean-up crew (nonfactorv personnel, exposed during the months May-July), l!8 men; and (C) plumbing, painting, and insulating per sonnel (nonfactory workers, exposed during the months May-July), 44 men. During the explosion in Amsterdam, two oper ators were present in the building. With the ex ception of these men, who were probably exposed primarily by the inhalation route, all other work ers used safety masks and were probably exposed by dermal contact. Chloracne was the most com mon and prominent lesion observed following 2,3,7,8-tetra-CDD exposure (26/44 examined in group A, 10/16 in group B, and 8/16 in the group C). Liver function tests (thymol turbidity and serum glutamic pyruvic transaminase and serum glutamic oxaloacetic transaminase) did not in dicate liver damage. A few men complained of fa tigue. The latent period between exposure and the appearance of chloracne, characterized by comedones, pustules, and cysts on the face and sometimes on other parts of the body, was ap proximately 4-6 weeks. Sometimes, erythematous and edematous skin lesions, possibly due to phe nolic compounds, were noted one day after ex posure. No skin lesions (chloracne) were reported Environmental Health Perspectives in family member? of the employees. Of group A, 3/44 workers died, one of pancreas carcinoma in 1964, one of myocardial infarction at the age of 69, and one of a traffic accident. Of the IT/13 traced individuals in the B group, four have died (three from sudden death, probably of myocardial infarction, at apes, 41. 53. and 65, and one of illdefined pulmonary or cardiac cause at age 44). Only 32/44 of the C group were traced, and one of them died of sudden death, probably myocardial infarction, at age 50. Jirasck et al. (104, 105, 109) studied 55 subjects from a cohort of TS workers from a factory in Czechoslovakia producing 2.4,5-T and pentachlorophenol, who were affected by chloracne. The workers were probably exposed during the years 1965-1963 to unknown levels of 2,3,7,8-tetraCDD. A significant symptom was the disturbance in porphyrins metabolism with signs of porphyria cutanea tarda. Many workers also suffered severe hepatic and neurological damage and had raised blood levels of cholesterol and total lipids. In the first years of follow-up, five deaths were observed, two from bronchogenic carcinoma at age 47 and 59 (only 0.12 lung cancer deaths were expected from national mortality statistics), one from atypical atherosclerosis at age 57, and one from the acute occupational intoxication. One further death, probably from liver cirrhosis, has recently been observed and 50 workers are still being fol lowed. Many workers continue to show lipemia and hypercholesterolemia and have developed prediabetic changes and hypertension. The work ers lost to follow-up are mostly foreigners who re turned to their country of origin. In July 1976, an accident in a TCP-producing factory in Meda, Italy resulted in the con tamination of the towns of Seveso, Meda. Cesano Mademo, Desio, Nova Milanese, and possibly oth ers of a large, densely populated area called the Brianza di Seveso with a total population of about 220,000 inhabitants. A retrospective health survey conducted on the workers of the ICMESA factory revealed that two workers among those directly involved in the production of 2,4,5-trichlorophenol suffered from skin lesions previous to July 1976. These facts may be indicative of a previous 2,3,7,8-tetra-CDD exposure. A large and intensive follow-up program is in progress in the Seveso area; data were presented about the first dermatological, neurological, clini cal, and laboratory findings, as well as about fetal damage. Dermatological examinations, including the screening of 32,000 children, resulted in the finding of hundreds of children with skin lesions, 135 of which were eventually identified as chlor- November 1980 acne; 59 cases were from the more contaminated area (Zone A). However, precise description of diagnostic criteria and accurate anamnestic infor mation, including, among others, data on places of residence, were not included. This information is needed before evaluating the meaning of the chloracne incidence data by territorial areas and efforts should be made obtain it. Chloracne cases were not systematically searched for in adults. Neurological examinations showed both signs of subclinical neurological damage and cases of clini cally detectable polyneuropathy in adults (34/338 persons from zone A and 8/185 from the sur rounding areas). In about 30% of 1654 adults from both A zone and nearby zones, hepatomegaly was reported to be present on clinical investigation. No informa tion, however, is given on the criteria by which the hepatomegaly was evaluated. The same per centage of abnormalities was observed in one or more liver tests (mainly glutamyl transferase and serum glutamic pyruvic transaminase and serum glutamic oxaloacetic transaminase). Ex tensive monitoring of various hematological pa rameters from 25,000 persons is now in progress and the data are expected to become available during 1978. Results of this investigation should allow a better understanding as to whether or not these alterations are caused by exposure to 2,3,7,8-tetra-CDD and PCDDs. So far, immunological investigations, cyto genetic research, and embryomorphology analy ses on cases of therapeutical abortions have not given abnormal results. However, the study of the frequency of congenital malformations and spon taneous abortions seems to be very difficult to ac complish. The importance of a systematic study on this subject has been stressed by the Working Group, because the questions on the teratogeni city of 2,3,7,8-tetra-CDD in humans cannot be solved by any ocher study. A preliminary mortality study has been pos sible in 2 of the U towns of the Seveso area. The 1975-1977 mortality rates from liver cirrhosis and leukemia in these two limited zones of the Seveso area were compared to that of a nearby area (province of Varese). Within an overall mortality which did not appear different, an increase of deaths from liver cirrhosis and from leukemia was noted. The validity and significance of these observations should be carefully evaluated. Recommendations A chemical analytical program should be en couraged to identify and standardize analytical OOO iS t H MtlhI 1111 - r_ T kblf 7. Kpiiltnij(iluj(irAl ilu d ic i on 2,3.7.6-lctrochlorodib<:nio-p-dtoxin; tium un exposure episixlrs rau sed b> a rrid rn la l or iN t u palional n p < u (r o r r u r r in j in facloriex producinc 2,i,S-(ricliloroplienol and/or 2,1,5-Irichlorophenoxj arctic arid. Town and country Numlwr Year of of exposed exposure persona Clinical follow-up and cohort studies Observations tu date Proposed actions CuininuriU and recommendations of the NIEI1S/IAHC Working Group Accidental exposures Nitro, West Virginia, (USA) 1343 Ludwigshafen/Uhetu, Federal Republic of Germany 1863 Amsterdam, The Netherlands 11)63 Uulaover, Derbyshire. United Kingdom 1363 223 Only 36 individuals were No significant lung-term followed, for u period of observations are yet avail 4 years able (some followed-up individuals bad symptoms of severe intercostal neuritis 76 A mortality cohorL study has 6 Cancer deaths were ob conducted 21 yr after tho served: 3 of stomach cancer accident; alt exposed workers in the age group 60-63 were traced for a total of (significantly higher lhan 1626 person-years of ob expected), 2 uf uat-cell servation carcinoma of the lung, and 1uf colonic adenocarcinoma 106 Preliminary observations Of 3 deaths, S or 6 were from on mortality are uvuilahle; cardiovascular diseases, 6 33 exposed workers have probably from myocardial been traced up to 1377 infarctions; the myocardial infarction death rale seems higher in the most heavily exposed workers uffected by chluracne. One worker, who did not develop chluracne, died from paucreulic car cinoma 14 months after the accident; huwever, he com plained of abdominal pain 00 Of the workers belonging prior to the accident One worker is known tu to the original cohort, 60% have died from coronary are still employed and Lhromhusis routinely undergo clinical and laboratory investiga tions Mortality cohort study being planned Follow-up tu bu continued Full report planned for 1378 Epidemiological cohort study to he planned when the results of the present clinical follow-up investiga tion become available Efforts should he made to trace the individuals who were exposed, possibly through the employment compensation files. The results of the continuing follow-up study should periodically he made avail able. Efforts should he made to trace all the workers who were exposed. Eiforts should be made to trace all the workers who were exposed. Environmental Health Perspectives J_j_ JjL tlll(ttill] I li Ululiliifcdr W i t t i a ^ u i i ^ i u.LL. tA U rih M d tfa N d k 0861 quAOX Muda, Uriauza di Seveao,Italy Occupational exposure Czechoslovakia 1976 19661969 V A clinical follow-up of Ihu Initial clinical observations Among other ongoing inhabitants front the more showed a high incidence investigations, a contuniiuatcd areas ia of 2,3,7,8-letra-Cl)D- long-term morbidity being curried out. At the dcpcndeiiL skin lesions study bus been Limo of tho accident, living uinong children living in initialed In Zone A was a population the more contaminated area. of 730 people, with 200 of Also, a number ef persona those being between 0-14 resiiling in the zone sur years of age. Of these 730 rounding the more con pursous, G23 (126 between taminated areas bad skin 0-14 years of age) were lesions, but with poorly de fotlowcd-up. Zone 1) con fined, clinical features; these tained a population of 4732 lesions muy be the result inhabitants with 1293 of 2,3,7,8-tetra-f'D)> ex between the ages 0-14 years. posure. Moreover, both An accurate count uf those clinical and laboratory find followed in Zone 11is not ings suggest an Increased available, hut 043 young incidence of hepatic suffer sters between 0-14 yeurs of ance among adults living tfge are included in the in the highly contaminated follow-up areas. A preliminary mortal ity study suggests that al though the overall rules from 2 Suvcso'tuwna are not differunt from a nearby urea, an increase uf deaths from liver cirrhosis and leukemia was nuled passible teratogenic and other adverse reproductive und developmental effects from 2,3,7,8-tetra-CDD exposure should be investigated. A -mortality register ami pop ulation files, suitable fur adequate descriptions uf morbidity data, should be established. Further, the cancer registry that already covers a nearby province, should be extended to in clude the Seveso area. 80 A follow-up baa been made regularly on 65 workers of the original cohort. The workers losL to follow-up are mainly foreigners who left the country Five patients died during the first 6 year-follow-up * period: 2 died from bron chogenic carcinoma and 1 from u rapidly developing atypical atherosclerosis. One further duatb, probably from liver cirrhosis, has recently occurred. Many of the workers are now sulfering from hypertension and show signs of hyperlipi demia and hypercholeste rolemia us welt us prudiulielic symptoms ami signs Follow-up to be con tinued. A 10-year report will be prepared during 1978 The results of the continuing follow-up study should periodically be made avail able. * Mo reliable information was available to the Working Group about the actual number of exposed persona; the entire area bus a population of approximately 200,000 people. methods used, to eataloirue products contami nated with PCDDs and PCDFs, and to establish a register of known PCDD and PCDF standard samples. The Working Group unanimously recommended that a system he developed for an international exchange of information and research coordina tion on the health effects of chlorinated dibenzo-pdioxins/chlorinated dibonzofurans. Further, and in particular, the following three areas were in dicated as deserving special attention: 1. Development of sensitive and reliable mea surements of body burden: improved, more sensi tive, and less expensive analytical technology should be generated. Standardized sampling (air, water, soil, tissues and body fluids, environmen tal) , preparation, clean-up, and analysis should be promoted; 2. Development of common protocols for clini cal examinations (including reproductive experi ence) and, in particular, design of a protocol for basic core information; 3. Development of an international registry of exposed persons to serve as a basis for long-term follow-up: this was considered especially impor tant because the relatively small size of popu lations involved in individual exposure episodes are ah obstacle to risk assessment and thus pool ing of data is almost a necessity. The Working Group recommended that IARC explore the technical and financial feasibility, pos sibly in cooperation with other national and/or in ternational organizations, of setting-up such a permanent mechanism which could include as a minimum starting program: (a) a periodical, per haps biennial, meeting to up-date the progress of ongoing studies, and to identify needed develop ments; (b) an exchange of relevant information accruing during the interval between meetings; and (c) a register of chloracne cases, containing simple, essential information in a standardized form. This PCDDs/PCDFs exposure-related sign may help to better define an exposed cohort popu lation suitable for long-term follow-up. This report represents the views and opinions of the Q.S. NIEHS/IARC (National Institute of Environmental Health Sciences/International Agency for Research on Cancer ad W Working Group which met January 10-11. 1073 in Lyon France to review the history of human exposure to these chemicals, to collutc current information, anti to plan anti fore cast needed new directions. The meeting was funded jointly by NIEHS and IARC. REFERENCES 1. International Agency for Ruserach on Cancer. (ARC Monographs on the valuation of the Carcinogenic Risk of Chemicals to Man Vnl IS, dome Fumigants, the Hertiicides 2,4-D and 2.4,5*T, Chlorinated Dihenzmlitjxins and 2.*6 Miscellaneous Industrial Chemicals. [ARC, Lyon. August 11)77. 2. CJussolin. R. K,, Hodge, H. C.. Smith, R. f\. and Glejwtm, M. N. Clinical Toxicology of Commercial Products, -1th cd., Williams & Wilkins Co.. Baltimore. 1976. .`I. International Agency for Research on Cancer, 1ARC Monographs on the evaluation of the Carcinogenic Risk of Chemicals to Humans Vnl. 13. 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