Document peQVdpKbE5EV3OdXVyGaOwMz6

* ^tCE. This matoraal may w ooprxls fcnWrunirirmu/ IlmAli r. r\prri<i n Vo!. U, pp. U7-172. im Human! Exposure to Polychlorinated Biphenyls and Polybrominiated Biphenyls ^ by F. Gordie,* P. Corneiiussen,* C. Jelinek,* B. Hackley,t R. Lehman.t J. McLaughlin,** R. Rhoden,tt and R. Shapirott polychlorinated Biphenyls Inlrntluclion Although the polychlorinated biphenyls (PCDs) t c been used in a wide vai iety of industrial apph< in the U. S. from 1930 until 1970, when their iVint'ulioii was volunlarily restricted lo closed 11 i'r ttis, there is scant information on human expo > ic in adverse human health effects in the U. S. In t'.e U. S.. minimal human exposure of the populai> >-i to rcits is limited to food, air, and water, while i human exposure appears to be limited so fishermen consuming fresh water lish from si'n` liriinoicd streams and lakes; and to occupa *1 exposure in industrial workers. Itirt.iry Kxposure to PCBs The May 1972 Report of the Interdepartmental 1 nice tm PCBs (/) summarized the findings in (sM vaaipling progiams conducted by the Food and * *r4 Dru( Administration, 200 C St., S.W., v"' <.#(, |> c. jo;w. * .ml Muinc Fisheries Service. 3000 Whitehaven Si.. ` 'Mihi, I). C. 20233. lf *'f tci'loiiy and l-nvironmcnijl Conservation, N,v ` " ' ** .'n,l Alnio^phcric AUniirmli jlinn, Dcpjrlmeni of I1' i '', ***** *** *'IM* Consliiulinn Ave., N 'V., Washington, Y ' of ti.otnpcal Science. Bureau of Diomedical Sci- * Y " 1 Sl s . Washington, D C 20:tU , ` ' ,n'"'uk fur r.nvironmeniul Health Sciences, 1 ' KcKJich Tnancle Pork. N. C, 27709. Drug Administration and the Department of Agricullurc. Jelinek ct al. (2) have provided an update lo that summaiy and evaluated trends which is pre sented below. The 1972 Task Force report (/) outlined ihiec broad sources of food contamination. These arc re stated here in order to show which sources have been effectively controlled and which sources appar ently persist, as reflected by results obtained in con tinued food sampling; (1) environmental cont.mmalion (background levels of PCBs in fish from lakes and streams); (2) industrial accidents (isolated inci dents involving direct leakage and spillage or contact of PCB fluids and other PCB containing matenuls on animal feeds, feed ingredients, or food)1 (3) food packaging materials (PCB migration to food pack aged in PCB-contammatcd paper product:,. As discussed in the 1972 Task Force report (/), there were a number of other positive findings in foods which could not be traced to one of these broad sources prior lo 1972 and the souicc of such occasional findings remain speculative. However, in more icccnt years, essentially all positive find ings of PCBs in the food supply have been attribut able to one or more of these three sources. Jelinek and Corneiiussen (2) reported that for the 1969-1975 peiiod, there lias been a significant de crease in PCB levels in all foods with the exception of fish, where no particular trend has been noted. Fiom that observation they concluded (li.it proce dures instituted to exclude the use of PCBs in "open" applications have been effective, but that more needs to be done to prevent their entry imo the aquatic environment. Jelinek and Corneiiussen (1 > presented data on J"'i 197,1 157 *T HONS 206385 FDA's sampling program showing a very conclu* sive decline in l:Y 1973--1V75 period in terms of ocCinrcncc rate of PCli-. and maximum levels found in milk, eggs, cheese, annual feeds and components, processed fruits, and baby foods Except for fish, occurrence rates in FY 1975 had dropped to ?ero or less than ICA for all categories, and there were no findings in excess of the existing temporary toler ances, Similar data were presented covering USDA's sampling of meal and poultry which also showed a decline, to 0.3% positive and only 0 69fabove the temporal y tolerance. Jcltnck and Corueliusscn (2) also reviewed FDA Total Diet Study findings (FY '71-75), which showed that all food classes of the total diet have declined to no PCB occurrence and no calculable daily intake of PCBs. except tn the mcat-fishptuiltiy composites About 40% of these composites continue to contain detectable PCBs. although only traces have been detected in the latter years. The limn of qu,imitative detection in the Total Diet Study is about 0 05 ppm; positive findings below tliai level ate gcnertilly reported as traces since they arc not reliably quantitated. Occurrence of PCBs ended in 1973 in all other categories notably in dairy product composilcs and the composites of grain and cereal products. Tins probably reflects the control measures effected on animal feeds and on the control of ingredients in recycled paper used for food packaging What icmains, based on the Total Diet Siudy. is a continued low level occuriencc (about 409? positive and only nt trace levels) m the mcat-fish-poullry composiies. The fact that levels in these composites have de clined to only traces further supports the inference that the meat and pouliry and eggs no longer contain delectable PCBs and that tbe low level findings are primarily due to the fish in those composites. This would imply ihui ihc PCB levels in the diet may have "bottomed out" and may remain static until such time as there Is a change in die levels for fish. Estimates of dietary intake of PCBs based on the Total Diet Study must be taken as gross estimates because only traces are currently found and some type of estimated value must be assigned to those traces to calculate microgram per day intakes of PCBs. Jelinck and Corncliusscn Q) used a set of consistent assumptions for those traces in comput ing the daily intakes for the FY `71-75 period. Their calculations showed a steady decline from 15 jig/ day down to S 7 /ug'dny. with all of this coming from . the incat-fish-poultf) group in FY `74-75 (minor and declining portions attributable to other food classes in citrher years), Re view of this information implies that, although the various assumptions for trace residue reportings and varying food consumption data have a signif icant effect on daily intake calculations, an overall estimate in the order of 5-10 ^g/d:iy PCB diemry intake of PCBs for the general public seems reason able. This figure would uoi be applicable to diets which may include regular consumption of fish from certain locations wiih high PCB levels. PCB Residues in Fish Review of the data gathcicd by various agencies on fish residues indicates a serious incompatibility of sampling programs for obtaining data which reli ably define trends in PCB levels The Food and Drug Administration s primary concern is the levels which exist m the edible portion of commercially imported fish which arc marketed interstate. Therefore, in most cases, the heads entrails, skin, and fins arc excluded. Fuithermorc. FDA sampling has not included fish which are caught and con sumed locally (freshwater fish) and ihc sampling has dealt with 'lie most important consumption species which me piimai ily of marine origin and which gen erally do not coniain PCB levels as high as fresh water species from certain locations. In Older to dclcimmc the human exposure to PCBs through dietary fish, one must know the levels of PCBs residues in the edible portions of fish, and the amounts of the various kinds of fish consumed by the population'allafgc. and by special subpopulalions. Information has recently been compiled by the National Marine Fisheries Service-NOAA U) on the PCBs levels of these res idues in marine and freshwater fish and shellfish, and on dietary habits. Table 1 lists the 20 most important types of fish eaten in the U, S. today and the mean daily amount of each type eaten by the subpopulalions of actual users. Table 1 includes all diciary fish, from sport fishing and from domestic and imported commercial fishing. Tltcsc 20 items comprise 95% of the fish products eaten. The results are taken from informa tion in a recent seafood consumption study, spon sored by the Tuna Research Foundation, by the National purchase Diary of Schaumburg. Illinois {4), and National Marine Fisheries Service data on the amount of fish and shellfish processed and distributed in the U. S. Several items in Table I are worth noting for purposes of the present anal) sis. Although 93% of ihc U. S. population (197 million) cat fish, the a\`cragc annual per capital consumption of fish is small 15.0 Ib'vcnr; a large 'unclassified" fish fraction exists in the U. S- diet, ranking just below tuna in importance, the ma.ior portion of many of our most familiar types of seafood is im ported, and freshwater species, led by trout, bass, 158 Environmental Health Perspectives HONS 206386 . , i . r t > t' 1 ' J 1 1 , , , *nd catfish, compile about 9% of our tola! fish dicl. A compil.ilion of PCB d.ii.i. rcprcxcnimg the rc- soils of a!! Lhc measurements known to NMI-'S of PCBs in fish used in the U. S. diet is presented in the Compendium of PCB Data (/). It includes dut.a from government leports, and state ;md private publications. Alt effort was made to include current. unpublished data fiont marine laboratories The compilation includes the results of a comprehensive literature search by the NOA A-Ennionmcntnl D.iia Service (EDS) An EDS-CNDEX data search for unpublished data and a EDS-OASI.S search were made, dossing mnniic food species with PCBs, Two significant sources of data--the 1975 PDA Market Basket results, and the results of the extensive analyses by the New York State Deparlmeat of Environmental Analyses (5)--were not available to NMFS at the time the Compendium (4) was published. However, PDA has indicated that the 1975 Market Basket results do not differ dramaliciiliy from 1973/4 daia Preliminary results of the New York study arc included in Table 3 below, Table 2 summit! izes the PCB information assent bled in the Compendium relating to the 20 most im portant kinds of dietary fish identified in Table 1, Although at one time or another, some PCB mca surements have been made on many fish, Table I points oul the inadequacy of information on PCB residues in die most impoilant Hems m die fish diet. Sampling nnd analysis have been spoi.idic and not designed to monitor bends in human expuMiic Systematic surveys of neither the important items nor the species most likely lo be contaminated have been undcitakcn. Very few recent measurements have been reported. However fragmentary the data on PCB levels may be, (hey do not include a single measurement exceeding t ppm in any of the ten mosi important fish foods, except for Dover sole and ct.ib taken in the immediate vicinity of Los Angeles sewerage outfalls, and crab living on contaminated sediments in Upper Chesapeake Bay No mote than I 6 ppm has been rcpoitcd in items 11 through 20 m impor tance. with the exception of frcshwaici bass and catfish living in river and take areas known t0 be contaminated with PCBs Nonetheless, as em phasized in Table 2, there have been no PCB men- surements on the impoilant unclassified dietary fish items, nnd the analytical information is in no in stance systematic enough to permit an estimate of the actual mean PCB values, hence human expo sure. The strongest statement that can be made, based on the incomplete data suminanzcd in tile Compendium (4), is Ihe most of the important fish Table 1. Fish and shellfish consumption in Ihe United Stales (September 1973-August 1974)." f f Total 1 Tuna (mainly canned) Unclassified (mainly breaded. including fish sucks) 1 Shrimp Ocean perch* 1 Flounder ' Clams l Crabs'!obstere Sulmon 1 Oysters/scaJIops Trouir Cod* t Bass* Catfish' 1 Haddock* 1 Pollock* Hemnp'smell Sirdjnc* 1 Pike' Hilibul* . 1 Snapper Whjlinp All el Iter classified * NMt'S dot* U1 * Mainly imports. ' Fresh water. Rank * 1 2 3 A 5 6 7 t 9 9 11 12 12 12 15 ' 16 17 It It 20 Amount, 10* tWyr 2957 6)4 . 542 301 149 . 144 ID 110 101 ss tt 78 73 75 73 60 54 35 32 32 25 152 Percent of loint by weight too. 21.4 It.4 10.2 5.0 4.9 3-t 3.7 3.4 3.0 3.0 2.7 2.5 2.5 2.5 2.0 I.S 1.2 1.1 1.1 0.9 5,1 Number of actual users (million si 197 DO 6* Mean amount per user. g/day IS.7 6.1 10.0 45 19 31 It D 19 14 9 12 7.6 7.5 11 .H 8J 9,7 8,6 7.6 '10.6 6.7 7.8 12.3 t.I 11 0 12.1 8.6 6.8 10 2.5 * 5,0 4.3 3.2 6.7 17 4 80 9.3 9,7 June 1978 159 *er HONS 206387 T meat items cnicn in the U, S. prob.ibly conldin mean I'CH ic.siduc tuy'da well below 1 ppm. Fragment,try evidence jilso lends to the conclu sion Hint tlic PCU levels in fish liver, toe. and oil arc approximately ten times lhat in the edible muscle and the PCI3 concentrations arc greatest in the older. larger, oily fish, especially those that spend part or all of then lives in contaminated lakes, rivers or estuaries. Table 3 lists the location of the species in which Table 2. Maximum rrporlcd fCll residue levels In fish muscle (while meal). Rank* | 2 3 4 5 6 7 8 9 10 tt !2 13 14 15 16 17 IE 19 20 Kind Tuna UnctiishiftcJ (mainly trended) Shrimp Ocean perch Flounder/sole Chuns Crabs/lobsier Salmon Oysters, scallops Troul (excluding lake Iroul) Cod Bast Offish Haddock Pollock Hernng/smell/sardtncs (marine! Pike Halibut Snapper Whiling Range and man level reported, ppm 0-0.49 no dal( 0-0 167 0-0.25 0.6,3' 0-0 819 0-4.9'* 0-05 0-0 43 0-0 56 0-0 4 0 3-8 A' 0-4.4' 0-1 16 0.0 0-1.6 0-0 65 0-0,149 0-0 1 0.0 (1971) (1971) (1974) (1972) (1974) (1972) (1974) (1974) (1972) (1974) (1974) (1974) (1974) (1974) (1974) (1974) (1974) (1974) (1974) Mean Jevd n the U, S die Unknown* Unknown Unknown Unknown* Unknow n* Unknow n* Unknown* Unknown* Unknown* Unknown* Unknown* Unknown* Unknown1 Unknoss n* Unknow n* Unknow n* Unknown* Unknown* unknown* Unknown* * These 20 items compose 95CS of the fish in the U. S. diet. * Probably well hetow t ppm. . ' Single Dover sole Liken near Los Angeles municipal sewerage oulfatt. The mean value of tole samples taken in (his vicumy was I 3 ppm in 1975, Mean values of other samples taken aw ay from out fulls w ere less Ih.in ( ppm in 197J In any case, although Dover sole is an important food fish in Northern California it is not taken commercially in Southern California wnlers * Single yellow neck crab taken near Los Angeles outfall-mean oT group including I his crab w as less than t ppm. A composite of Upper Chesapeake Bay crabs contained I 2 ppm tn 197-t 'Taken m IV74 from S( Croix Rncr. Wisconsin, mean of four while bass was 6.2 ppm. 'Taken from Mississippi Kiver, Minnesota, mean of a sample of five catfish was 2,5 ppm. Table 3, Arras si here at least one example ofhlgh PCB residue Icsels (> S ppm) levels base been reported In the listed species,* Species Location Sniped buss Chub Carp Chain pickcrei, alcwife Coho snfmon Chinook salmon Slectlirad Iroul Lake Trout Smallmouih boss While perch Ale wife Whuc tucker Walleye Largcmoulh bass Yellow perch American eel, crabs, sturgeon Rock bass, catfish Blue fish Hudson Riser, N. J. Lake Michigan Mississippi River. Minn,, Lake Onandaga, N, Y, Hudson River Lake Michigan, Lake Ontario, Hudson River Lake Michigan, Lake Ontario, Hudson River Lake Michigan, Lake Ontario Lake Michigan. Lake Ontario. Lake George. N. Y. Lake Onnndaga. Gencssec River. N Y. Hudson Riser, Mohawk River, St Lawrence River Lake Onandaga, Hudson River Hudson River Hudson River, Mohawk River Hudson Ktver, Mohawk River, Black River, N. Y. Hudson River, Mohawk River Hudson River Hudson River ' Hudson River Long Island Sound (muscle from one large oil foh coni.lined S ppm) " Includes rccenl d.u.i from New York Stole Department of nnvironmcm.il Converv .itiun not ns hide J in the NMI S i ompilalion The Hudson River above Tort I dward, N. Y., is nol contaminated wilh PCDs, and llw residue level* m fivh arc quite low. ICO ICiivil onmcntnJ Hciiitli Fcrspccfhcs Tr-vv- MONS 206388 high PCB levels, exceeding the FDA 5 ppm guideline, have been rcpoilcd Although the trout, salmon, and' chub in Lakes Michigan nnd Ontario nnd the Hudson River bass, perch, nnd cc! consti tute only a few percent at most of the national fish diet, in some areas they me a significant part of the fish diets. In order to discover what is presently known sboul U. S. fish consumption habits, numerous government and pnvalc sources were consulted, A number of prc-1970 siudics are available, including a 1969 NMFS Survey of Fish Purchases (6) and a 1968-70 HEW Ten Slate Nutrition Survey (7). in addition, a few specialized reports have been pub lished, including annual FDA Regional Basket Sur veys (S) that do not include fish eaten m restaurants and institutions or by sport fishermen, and surveys by the Sport Fishing Institute (9) and a ! 974 Texas A&M Analysis of Seafood Consumption Patterns in Texas (,10). Howcvci, the most up to dale and com prehensive data are available in the previously mentioned 1973-74 Seafood Consumption Study by the National Purchase Diary (4). Table 4 summarizes results of fish consumption demographic information that defines the number of U. S, consumers who would exceed an arbitrarily set dietary microconstituent level To date, this kind of information is available only for total dietary fish and otic subcomponent, tuna Table 4 indicates that 75 million U. S consumers cat more than the national average of 18.7 g fish per day and 29 million would exceed the present dietary intake limit of PCB (175 ^g/day) if the 35 or more g/day of fish eaten was contaminated on average to 5 ppm, the current FDA guideline level There is, of course, no tvidcnce that the mean PCB level in fish is any where near 5 ppm, Nonetheless, should it in the future reach 1 ppm, then by an extrapolation from Table 4, an estimate can be made (hat about 200.000 U. S. consumers would be exceeding the 200 ^tg/day FDA limit. As another hypothetical case, if the PCB level in tuna should ever reach 1 ppm, then about 5,000 tuna fish consumers, those who cat in excess of 175 g/day, would exceed the 200 /xg/day limit from tuna alone. Table 4. Distribution of fish consumption by U. S. consumers * Level of consumption, t/d*y 0 tt.7 (ntron*l *vj ) 35 50 too (50 Number, thousands of consumers Total fish Tuns >97,000 75,000 29.000 14.000 2,000 400 130.000 5,700 1.300 400 43 10 Derived from graphs on pp, 21 anil 23 of the Seafood Con-, sumption Sludy (4). June 1978 Survey data do show that in general U S. fish cuicrs include a wide v.rncly of fish items in their diet. Thus, even if certain items conimn love micro-constituents at or near FDA guideline level, the great mnjonty of consumers would receive only a small Faction of their average dietary intake from these sources. Clearly, there is a need for demographic informa tion, similar to that available on toml fish nnd Ulna, on the oilier principal foodfish Hems in the U. S. diet; and a need to extend and bcticr measure (he htgh-consumplton lad of the distributions, lo get a correct picture of the number and type of consum ers eating in excess of 100 g/day of any single fish product. Human Exposure from Eating Fish At present, it is difficult to estimate human expo sure to PCB from eating fish, cithci for the popula tion as a whole or for subgroups at higher usk Fragmentary evidence suggests that the exposure to the population as a whole from PCB residues in ingested fish is probably well below 19 / p/dayconsumcr, based on PCB levels which arc piobably well below I ppm and 19 g fish consumed/day. Although it is important to know the total popu lation exposure, the first pi ioi ity should be given to defining the dietary intake of PCBs in special sub populations at high risk by reason of high consump tion of fatty fish or high sensitivity to the toxic ac tion of PCBs. Such populations might include preg nant women nnd young children, dieteis, low in come groups, and sport fishermen living in coastal and lake regions where there is known PCB con tamination. Primate studies suggest that pregnant women, young children and dieters, will be par ticularly sensitive to PCBs and in some areas tow income groups may rely heavily on fish for food. For each subpopulation. the amount nnd kind of fish in the diet and the PCB residue levels in the fish eaten must be obtained in order lo determine expo sure. None of the necessary information to define the human PCB exposure in subpopulations is presently known. The first priority in systematically monitoring and analyzing for PCB residues is fish should therefore be among the oil fish such as salmon. Iioui. mack erel. shad, sardines, herring, blucfin tuna, sable fish, whitefish, striped bass and blucfish, thai have been identified as significant food items m the diets of special subpopulations of consumers. Although only minimal dietary exposure to PCBs may occur through food, there is evidence of po tentially significant exposure in those subgroups of the population who regularly consume fiosliwnter fish from waters which are contaminated with PCBs 161 HONS 206389 at levels which cxe'ccd the FDA temporary toler ances. These subgroups of the population would in clude spoils fishermen and others who consume locally caught freshwater fish in surveys conducted by the Stole of New York and l:DAt samples of 17 species of fish were col lected fiom 10 pomis on the Hudson Riser between Glens Falls and Alpine. 17 samples were collected at Glens Falls a ml 68 samples below Glens Tails. The data fiom these surveys indicate that 53 out of 68 samples of fish collected .it or below Tort Ed ward (approximately 7 nnlcs below Glens Falls) contained PCBs m excess of 5 ppm The average level of PCB contamination in these 68 samples was 31.3 ppm, In contrast, only trace 1cxels were found in the 13 samples obtained at Glens Tails A high proportion of fmfish and eels from all sampling points below Glens Tails contained PCI) levels tn excess of 5 ppm The Fort Edward sampling point had the highest levels for the species examined, with individual samples ranging from 20 ! to 178 ppm. Tsvenly-cight of the 33 samples of coho and Chinook salmon Horn Lake Ontano exceeded 5 ppm, with a range from 21 ppm to 24.6 ppm, Of the 4 samples of lake tiout tested, results were in the range of 10 to 15 ppm, All other species of fish sampled Horn l.akc Ontario were at 5 ppm or less PCBs. The Great Lakes represent another area of the nation contaminated with PCBs. The Michigan Water Resotti ccs Commission (IJ) has reported that many surface water samples contained PCBs at concentrations above the detection hntii of tO ppt. Ten significant levels of PCBs have been found in rivcis and streams discharging into the Great Lakes. Effluents from wastewater treatment plants servicing industrialized communities haxe been . found to be highly contaminated. Sampling surveys of Great Lakes fish have shown that most species tested contained delectable levels 'of PCBs and that residue levels were gcncmlly pro portional to fish size (age) and highest in the pred ator species. Except for whitefish. the species of commercial or sport interest (trouts and salmons) fiom Lake Michigan were found to be highly con taminated with PCBs. Data obtained fiom lake trout collected from various areas of Lake Michigan show mean PCB levels ranging from 3.06 ppm to 11.93 ppnt. The Michigan Department of Public Health has recently completed a study (/() which attempted to assess some of the consequences of human expo sure to I'CBs fiom the consumption ot sportsfish caught in diffcicui aicas of Lake Michigan. The study included exposed and control subjects from five mens of Michigan bordering on Lake Michigan Exposed situly subjects were those individuals who consumed at leas! 24 to 26 lb of Cue,it Lakes fish pci year. Contiol subjects were those individuals who consumed less titan 6 lb of Gieat Lakes fish per year, A preliminary assessment of the Findings in the study indicate that the most fictjucntly iccordcd quantity of fish consumed by the stiisly participants was in the 24-25 lb yr range. I he highest recorded fish consumption over the two-year period of the study was 180 Ib'yr and ibe highest single-season consumption was 260 lb Mean PCB levels m whole hike trout arc tepotied as 18 93 ppm in 1971 .md 22.91 ppm in 1974, and 12.17 ppnt in Coho Sulmun in 1973 and 10.45 ppm in 1974. However, companions of PCB levels in raw- vs cooked fish indicate that actual human exposme to PCB fiom Fish consumption is less than might be expected from the raw fish data This is not unex pected. since piepnration (trimming away fatty tis sue) and cooking have been shown to decrease the conccntiation of PClls. For example, the PCB level in cooked Lake Trout consumed by the study par ticipants ranged fiom 1 03 ppni to 4 67 ppm: in cooked salmon fiom 0.48 ppm to 5 38 ppm. and in otlici cooked fish (torn 0.36 ppm to 2 06 ppm These levels ate decidedly lower than the level of PCB contnminution reported in raw ttotn and salmon. PCBs were found in 501 blood and breast nulk specimens collected from study participants dining the study The values ranged from a low of 0.007 ppm m blood in the control group to a high of 0 366 ppni in the exposed group. Although there was a wide range of blood values for each quantity of fish consumed, there was a highly signiFicant corielnimn between the reported quantity of Lake Michigan Fish consumed and the concentration of PCB in the blood of study participants. Using a natural log transformation of PCB values, the correlation be tween amount of fish consumed and PCB blood tcvcls was significant (/ = 6-24. p < 0 0001), with higher reported fish consumption being associated with higher blood PCB levels No annual vatiation in PCB blood levels in hu mans could be demonstrated. The mean PCB blood values for the control and exposed groups did not appear to change markedly fiom 1973 to 1974. !n addition, abstinence from Lake Michigan fish con sumption for n petiod of 90 days or more did not change the PCB blood levels significantly. PCB blood levels over the abstaining period shows san ation but no steady decline in PCB. In fact, more subjects showed no change or a rise than showed a decline in PCB blood levels over lime. The calculated quantity of PCI) ingested by eating 162 Environmental Health Pi-rs]in.tivcs Ft* M*1 TT fMUl HONS 206390 l^nhc Michigan fish averaged 46 5 mg/yr and ranged ftoni i4.k7. to 114.31 mg/yr. PCB ingestion for each individual was detcimmcil by propoitiomng the re ported annual fish consumption by frequency of species eaten and the cooked fish PCD levels for those fish. The community average for cooked fish was used in instances were cooked fish determina tion wcic not available for a study participant. Be cause fish consumption was found to vary from year to year, the average annual consumption for each individual for the two baseline years of study was used in each ease, Results ftoni this study indicate the sttong likeli hood that the maximum allowable ingestion of ! /ig/kg body weight per day recommended for pro tracted cxposuic to PCB is being exceeded by the majoiity of the exposed group participants, and by inference, by a substantial number of individuals participating in spoil fishing and who consume quantities of contaminated fish The calculated mean daily dose received by the exposed group is 1.7 /sg/kg-day and ranges from 0.49 to 3.94 /ig/kgday. If the average annual rate of PCB ingestion from fish indicated by these study results were con tinued over the years, and if net accumulation oc curs, the average sports fisherman consuming con taminated fish could receive a tola! PCB dose equal to the 200 mg safety limit in appioximatcly 4.3 yr. Under the same set of assumptions, individuals consuming greater than average amounts of con taminated fish would reach the total dose level sooner. No adverse health effects or group of symptoms could be identified in the exposed group that were clearly ielated to PCB exposure. This implies that exposure to PCBs from eating contaminated fish at the levels observed and the presence of PCBs in these exposed persons has not caused any observa ble adverse health effects at the time of the study. However this docs not exclude the possibility that effects too subtle for detection arc occurring or the possibility of long-term adverse health effects. Yusho Considerable scientific interest has centered on the Yusho incident in Japan, where in 1968 human intoxication with Kancchlor 400, a PCB manufac tured in Japan, was noted when a heal exchanger leaked this PCB into rice oil ("Yusho" oil) which was consumed hy Japanese families The typical clinical findings included chloracnc and incicascd pigmentation of the skin, increased eye discharge, transient visual disturbances, feeling of weakness, numbness in limbs, headaches, and disluibnnccs in liver function. Most of the babies born lo mothers with Yusho had skin discoloration which slowly regtexsed ;is the childien giew m size. Adult Yusho patients hast piotracted cima.il disease wdh a slow regression of symptoms and signs suggesting a slow meiatuihsm and excretion oT ihe 1'CB in humans, probably resulting fiom a long biological half-life A review of the literature extent n> 1973 led to the following facts with respect to this uaeic incident m Japan The average PCB content of ihe rice oil in the dose-response epidemiologic xiudv was 2500 ppm. In tins dose-response cpidcmiolocic snub the a vet age cumulative intake of PCBs leadmc to overt symptomatology, was 2000 mg In ihis same study, the lowest dose leading io overt nmplomatoloey was 500 mg. The toxicity seen was ihe icsull of the ingestion of the PCBs coniammant in the nee oil. A summary updating of the Yusho incident was presented by Knralsunc in 1975 (12) This report affects the original conclusions enumciaied above PCBs Content of Yi/s/io Oil. The fust reported PCB determination was made on a canned contam inated rice oil produced on February 5, 1968. con sumption of which was associated wuh overt symptomology. One group of Yusho patients vvns as sociated with ingestion of this contaminated canned rice oil produced or shipped on Febru.ny 5 and 6, 1968 (/3). The detailed epidemiologic studies me given in the papcis by Kur.Usunc ct nl. U4) and Yiishumira (15) and summarized in English by Kuiatsunc ct al (/.?, 16, 17). Of 325 patients queried. 166 of 170 used canned rice oil pioduccd or shipped on February 5 and 6. 1968, and 143 of 155 used bottled nee oil shipped from February 5 to 15. 1968. Tnsukamolo ct al. (18), determined that the organic chlounc content of canned rice oils produced ot shipped on February 5. 1968. was 1000 to 1500 ppm. by chemi cal and activation analysis. Since Kancchlor 400 had a 48% chlorine content, if one attributed all the organic chlorine to this specific chlorinated biphenyl, then this canned rice oil contained, ns an average. 2500 ppm PCBs. Kuiatsune ct al (N) re ported that a qualitniivcGLC sui vcy of 109 samples of bottled rice oil shipped between October 1967 and October 196S showed "significant" PCBs con tent only in those samples between February 7 to 10, 1968, The largest amount was repotted in the sample of February 7, 196S, but the quantity was not given. No bottled rice oil samples ucic available for February' 5 and 6. I96S. However, in ihe paper by Kuratsunc cl nl. (17), the most marked con tamination of bottled rice oil was for that shipped on February 7, I96S; and the maximum chlorine content was 462 ppm. One may assume that this June 1978 163 MONS 206391 number applies to the sample or bottled rice oii of (12) gave a value of 134 ppm PCB for a rice oil Fchiu.uy 7. l%8 giving this sample a PCl3x content produced on Fchruaiy f0, 1968. Thus, the available of 924 ppm Kuiatsvinc el al, (12) reporting the work data does confirm a diminution of PCB lontnmina of Nayuy.imj ct <d i/V). gives ilie I'CLts analyses tor tion of the rice od with time This is summarized in thfee samples of time Vuslio oil, used by thiec in Table 5. dependent families with Vuslio, us approximately 600 to 1000 ppm. These were GLC/MS mca- Table 5. suiemcnts N'.ig.iy.imn ct al, (/9) described these samples as follows' ' Rice oil used by patients with Dale Source PCC conUfll. ppm Mel bod Yuso ("Yusho oil") 3 samples of rice oil used by 3 independem families uith Yusho in 1968. These iimplcs bad been kept in glass bottles xstih glass stoppei s at room temperature m our laboiutorv until 1974 when [lie analysis was made. ' Kuniisune (/J) Feb i. I96S Feb i ot 6. I%8 Feb 7. I90S Feb 10, I96S After I eb It 1968 Canned od Canned 1 `1 od (Jollied oil Bouled oil Boillcd bit 3000-3000 c.i 1000 924 134 Juw delectable Orenn't Cl GLCMS Orennic Cl ? GLen pointed out lhai these three samples weic canned oil and considered to have been produced and The icsolulion of the varying PCB values foi the shipped on February 5 or 6. 1%8. It was repented canned oil cannot be made. However, Kurntsune previously that, based on organic chiorinc determi (7) (19761 confumed that the production of nee oil nations. Tsukamoto et al. US) reported an average had been suspended for an unknown period of time PCB content of the canned oil of Tebiuary 3. 1968. prior to February 6. 1968, when it resumed. lobe 3900 ppm. Now. based on GLC/MS, we have Dose-Response. There were 1291 Yusho pa n PC 13 content of ca. 1000 ppm for ihc canned otl tients as of April 30. 1975 (20). Of this total group, sample of Tebiuary 5 or 6. I96S. the dose-response relationship was developed from What arc the possible explanations for this dis a deluded analysis of 146 patients (15 16) These crepancy m values'' One possibility is based on the 146 patients all consumed contaminated canned rice assumptions associated with the method of mea oil produced oil Fcbruniy 5. 1968 containing 2000 surement by Tsuk.imoio cl al. (/8); namely, deter 3000 ppm PCBs as Kanechlor 400 (IS). Tsuknmola mination of total organic chlorine. Thus, any or ct al. estimated that the lowest dose producing ganic chlorine present m the rice oil. which was not symptoms was 0.5 g. tt chlotitwtcd biphcnxt, would be included in the If the PCB content of this canned oil was ca. 1000 PCB analysis Some possibilities include chlori ppm. as discussed in the previous section, then the nated dibcnzoftirans chlorinated naphthalenes, average dose producing an oven effect was 0 8 g, chloiinatcd paraffins, other chlorinated aliphalrcs. and the lowest dose producing an ovetl effect was and nonbiphenjl aromatics. _ 0.2 g. */ Another possibility is related to the distribution, Causative Factors. Originally, rice oil con with time, of the contaminated rice od samples. taminated with a lical exchanger. Kanechlor 400, a Fcbiuary 3, )%S, occurred on a Monday. The first polychlorinated biphenyl, was associated with rice oil samples reported to contain PCBs were pro Yusho symptomatology. PCBs were identified in duced on this date (IS). If the leak first occurred the contaminated rice Oil consumed and in the blood sometime over the weekend (February 3 and 4. and tissues of Yusho patients. Therefore, the effects 1968), and production was resumed Monday morn seen were attributed to PCBs. ing. I'cbruaiy 5. 1968. then one xs'ould expect the In the review by Kurntsune el a!. (12), a new samples of this date to be higher in PCB content. foctoi was introduced into the system; namely, the Therefore, one would expect the first batches canned rice oil was also contaminated with chlori Monday morning to be highest with a diminution of nated dibenzofurans to the extent of 5 ppm. In ad PCB content with lime- Tsukamoto [IS) reported* dition. in this same paper Kurntsune presented data the organic cldotinc content of six canned oils pro of Nagaynma ct al. (19) showing polvchlonnutcd duced Monday. February 3. 1968. as follows- 1020, dibcnzofuians to be present in the liver and adipose l [70, 107(1 1080. 1030. and 1500 ppm. In the survey tissue of Yusho patients, while none wa found in of bottled otis. Kur.tistme et al. (/4) reported that that of a control gioup. The t .trio of PCBs to I'CDFs for those samples where 1'CIls were found, the in Kanechlor 400. a Yusho oil of February 5 oi 6, faraiest amount was in the samples of February 7 1968. in adipose tissue and liver from a Yuslui pa (Wednesday): and after February 11, ft was inferred tient were 50.000. 200, 144. and 4. respectively from llie paper by Kur.usune et J. U?) that the PCD Tlius. relative to Yusho oil. the liver wtth a PCB/ content of the bottled nee oil samples of February PCDF ratio of 4 and 1 appears to concentrate 7, 196S, was 924 ppm. In addition, Kurntsune etui. PCDFs seieclively relative to PCBs. 164 Environmental Health Perspectives HONS 206392 Relative to PCBs, PCDTs arc nbotit 250 tunes hi&hci nijhe nee oil than in K.mcchlor 400 [12, IV). (It should be noted ih.tt we aio comparing chlonpuled dibcnzobii.m content of an unused K.mcclilor 400 to that after prolonged use m a beat e xchnncer ) PCDFs may also be a factor in Yusho disease. In Hnolbct paper Naguy.ima ct a I [21) reported that it Is said ili.u the toxicity of PCD!" is said to be from 200 to 500 times that of PC13 At the lower factor (200). contaminated rice oil would be expected to he twice as toxic as Kancehloi 400. Also, in tins same paper Nagayninn cl al staled that the symptoms seen in Ytisho patients seemed to be moic severe than would he expected just from the PCB intake associated with the oil If PCDF is 200 to 500 times moie toxic than PCB. then contaminated nee oil would be 2 to 3.5 times more toxic than that expected from its PCB content alone. Kmalsunc ct al. {/.?) estimated that if the average amount of contaminated rice oil ingested by a Yusho-exposed person, is related solely in terms of its PCB equivalent, then the amount of oil needed to be ingested, on that basis, would be 1000-2800 ml. At a PCB content of 2500 ppm, this is an inges tion of 4 to 7 g of PCBs equivalent: whereas al a PCB content of 1000 ppm. this is an ingestion of 1,6 to 2.8 gnt of PCBs equivalent. The complexities and unccitainties associated with the most recent repoits of the Yusho incident in Japan, make it extremely difficult to quantify possible human health effects resulting from expo sure to PCBs atone. Occupational Exposure to PCBs The earliest reports of adverse health effects due to exposure of workers to PCBs in this country are probably Ihosc of Schwartz (22). who described skin lesions and symptoms of systemic poisoning among woi hers who were said to have inhaled clilorodiphcnyls; their complaints included digestive disturbances, burning of the eves, impotence, and hematuria. Patch tests with the chloiodtphcnyls were negative, and Schwartz speculated that mechanical plugging of the follicles of the skin as the fumes solidified on it were responsible for the skin lesions. The chlorine picscnt in the products was thought to then exert an irrilaiing effect on the plugged follicles and to thus cause suppuration. No quantitative data were reported, but n number of preventive practices were recommended. There have been numerous icports over the en suing years (23-251 of cutaneous eruptions and of systemic manifest,tiions (sometimes fat.il) as well, among marine electricians, machinists, capacitor and liiinsfotmcr nianutnctuiing workers, and others occupationally exposed to PCBs However in many oT these icports the exposures arc desenbed as having been to mixtures of chlorinated hy- drocai hoax, quite often of chlorinated naphthalenes and PCBs, The skin lesions described by Schwartz (22) Ii.ivc come to be designated generally as chloracnc Chloincnc can be produced by a number of chemi cal compounds, including cltlonn.Ued dibenzofu* mis nnd certain ixomeis of the chlorinated ihbcnzodioxins (29) Oily skin and large pores seent to picdisposc to the disease, while the opposite is itie ease foi smooth, lendei skin (30) Chloincnc also has occuircd among workers engaged in the pro duction of 2.4,5-T Ol) Pan of the chloiacnc tcsion resembles adolescent acne, but it is generally more sex ere. and lesion distnbution is inconsistent with, although it may be snpeumposed upon, adolescent acne It is known that chlotacnc can be p.oduccd by cither the svv tcrnic absorption of chku mated biphcnvls or the di rect application of chloracncgenic compounds to the skin. Systemic effects sometimes lesuti a(icr occupational chloracnc has manifested iiseir: (lie sc may include loss of appetite, nausea, edema of the face and hands, abdominal pain, vomiting, and burning and soreness of the eyes. No fullv sattsfactoiy explanations have been made of the develop ment of chloracne. Chloracnc is generally very per sistent. and there is no prcfeited control measure. An excellent review of this subject is that by Crow Q2). The U. S. occupational standards for PCBs are 8-hr time-weighted average exposure limits of 1 mg/m5 (skin) for (he 4252 chlonnated pioduct. nnd 0.5 mg/m' (skin) for the 5452 chlorinated product (CFR, Title 29. Part 1910.93) The Naliona1 Institute for Occupational Safely and Health has undo way the preparation of criteria for a recommended stan dard for occupational exposure to polychlotmated biphenyls. In addition to an environmental expo sure limit, (his document will provide compichensivc recommendations for medical surveillance, safe work practices, and engineering controls to en sure employee protection during occupational ex posure over a working lifetime, it is scheduled for transmittal to the Department of Labor in late 1976 or early 1977 NIOSH nKo is undertaking certain studies of employee populations (mainly in U. S. capacitor factories) in older to belter define the na ture and extent of any chronic and/or lifc-shoitcning effects of exposure to PCB. Piacltcnily all of the currently available informa tion on worker health and PCB expostite is found m foreign literature. For example, K.uppnhcn and Kollio (3-0 reported on relationships between the June 1978 165 MONS 206393 concciUmlion of PCBsJn the hlood of all, and in (he hdipos.c tissues of some. of 29 persons in ` good health" fiom three diffetent employee gtotips in Finland 1KuiIso has staled lji.it the cupacttoi plant woikcrs rcectvcil quarterly health eliminations. End. in addition to the clinical examination made at the time of the tnvesiiuanon scrum alkaline phos phatase. GOT, .rnd GP I~ ncm rtics weic determined; the six employees with the highest blood concen trations of PCBs also h.id BSP excretion tests per- foimcd All icsults wear noiin.il. In view of chirms based on tiinni.il cxpei intents ih.it PCBs can induce liver iiiicrosonuil cnzjntc actixiiv. ihc auihots also dclcrmmcd Ihc half-time of anlipjun before and after phenob.irbital induction (1 mg pheno- barbital/kg body wcrght/dny/3 days) for six capacitor plant employees and six controls, no enzyme induc tion was observed. Further, hecausc of claims that PCBs have effects on steroid metabolism, four capacitor plant workers were tested for ACTIi (scrum, presumably), all results were repotted to be within the noimnl intige (letter from S, Hemberg to A, C, Kolbyc, Jr,, 12/23/75)], Nine of the employees' had no histoiy of occupa tional cxposuic to PCBs. six of ihcm had handled PCB samples in an analytical laboratory, and the other eleven of them had been employed for 6 years in a capacitor factory xvhere Aroclor 1242 was used as Ihc impregnating fluid. It xvus stated that average PCB concentrations in the air of the capacitor fac tory had not exceeded "iniernnlionaHy accepted limits," and that special attention had been given to skin protection. H he Joint ILO/WHO Committee on Occupational Health, in its sixth report (3<S) rec ommended for international adoption a "safe con centration zone" of 1 mg'ni' fu chlorinated detiva- tives of diphenyl.] Table 6 shows the observed tissue concentrations of PCBs; the authors were unable to delect any biological effects of the approximately 50-foid larger PCB concentrations in the blood of the capacitor plant employees, compmcd to the "unexposed" control group, Ouw cl a). (35) conducted a survey to determine the (icgicc of absoiption and tlie health effects of cxposuic to "electrical grade" Aroclor 1242 (that "did not contain any impurities") for varying periods of time. PCB conccnti aliens in the air of a capacitoi factoiy in New South Wales, Australia, wcic mcnsuied. and 34 occupationally exposed em ployees (15 males, 19 females, ranging in age from 33 to 55 years) were examined and compared with volunteer controls (23 males. 7 females ranging in age from 20 to 50 \ears) having no history of occu pational exposure to PCBs, It is ooteworthy that Aroclor 1242 is not maunfactincd in Australia. Table (. Conrcntrjllort of PCItt.' PCtU in blood (fal basis), mg/kg Subjects Wurl s in Cdpjcilor factory Average Range 3 JJ i00-700 Persons handling PCBs m .m.ilyircal laboratory Persons without any special exposure io PCBs 53 33-71 5.4 3 6-9.9 * Daia of K.nppanert and Kotho (J4). * indix iduai samples. PCBs in adipose tissue (fal basis), mp'kg* 200 It 160 285 6J5 Nol analyzed 23 t.) Study pniamcicrs included occupational and medi cal histories, PCD-in-blood concentration esti mates, and liver function (scrum bilnubin. alkaline phosphatase, total piotcin, and GPT. and BSP excretionl tests. The authors noted that exposed workers tended to complain of eye, face, and skin "burning," that the PCB "fume" - . , h.is a pungent smell xx inch often causes persistent hotly odor, and that the employees xv.th higher blood concentra tions of PCBs complained most often of the skin lesions (one ease of chloracne, five cases of "an eczematous rush on" the legs and hands), although there appaicntly was poor correlation of blood PCBs xvith the severity of the complaints. No sig nificant health effects were observed among those of the 34 workers xvhosc blood PCB concentrations were below 200 ppb. There xvas a statistically sig nificant difference between the blood PCB concen trations of the exposed group and the conliol group {p' < 0.01), Table 7 shows the concentrations of Aroclor 1242 in the capacitor plant air prior to and after exhaust ventilation system "improve ments" had been made, [The Australian National Table 7. Aroclor 1242 concernration-; In Ihc nir Inside capacitor plant before and alter improicnienl of exhaust scnlitalJoit sjilcm.* Aroclor concern rat ion. mp/m* No. Area in Ihc impregnation room Before After 1 In unloading lank in 1.44 front of exhausl register from operator s breathing rone 0.75 2 In unloading tank not in front of exhaust register 2.22 0.7 3 General alnmxphete near lank 1 OS o.ts 4 Soldering nrea 0.32 0.08 * Data of Ouw Cl al. (j'6) 166 Environmental Health lVrxpcctm-s ViNrr* TT X 1 11...... . II II HONS 206394 I Health ,md Medical Rcscaicl) Council recom refined us that now in use, but h is thought likely mended 07) exposure limit values of I 00 mg/m' for lh.it some employees were exposed continually >ti I PCB.s of 42% ;in<i 54% chlounc content, respec concentidtions of scvcial nnlhgi ants per cubic tively). T.rblc 8 shows that there was ih> lowering of meter. I blood PCB concentration among those workers The Japanese literature is said to have contained * tested two months after tltc installation of a more no futther reports on mcnsincmcnts of PCB in .nr I efficient exhaust ventilation system and the con until the spring of 1972. just prior lo the suspension comitant recommendation to wear "suitable imper of their usage 1 he production of PCBs was discon 4 vious gloves'1 in order to reduce PCU absorption tinued in Japan in June 1972. and their importation through the skin The authors suggested that a fail was discontinued in (he following September At 4 ure to adhere spicily to the glove recommendation that lime Hasegawa et al (40) icpuiicd PCB mea I might explain the continued elevation blood I'CB surements m the air of one I'CB pioduction pi.mt 4 levels. Another possibility might be that PCBs were (Kancchiors 200-600. 0 005-0 02 ppnii, four t continually mobilised from stoiagc tn adipose tis capacitor mamifactuime plants iKnuexhlor 300, sues. 0.01-0.05 ppm), and one plant where PCBs (Kanccltior 300) were used as a heat exchange Table 8. Menrt blood Aroclnr (242 levels Before find after Im provement or exhaust senUluUuM and Ihe recommendation to use suitable glows.* medium (0 002 ppm) Peak values ol 0 17 ppm and 0.67 pptn, respectively, were found m a capacitor plant "air-riddance" process men and m a capacitor rR. etention times--M-e--a--n----b--l-o--o---d---A---r--o--c--l-o---r---le---v--e--l-,--p--b-b--- SLatislicaJ rctniive lo AlUnn 1 Before Aficr difference impregnating area where tank leakage had oc curred. Estimated (picsum.ibly 8-hi woik day) time-weighted average exposures of affected em 0.6? 281.6 477.2 None <p <0 0J) ployees were 0.02-0 03 ppm. Aitboine PCBs in ihe 1.31 135.1 . 225.4 None capacitor plants wetc icportcd to consist of 70-80% (p < 0.01) vapor for material corresponding to Kancchlor 200. 1.41 58.41 524.7 Significant and of pnrticulates huger ihan 0.1 fj.m for Kancchlor * (p < 0,05) 300. The authors attnbutcd the 3:1 vapor panicu * Data of Ouw et ai CJ6>. late mix to selective evaporation of low boiling components of Kancchlor 300. The Japanese Ministry of Labor (Regulation for Although no measurements were available, the Prevention of Disturbances due to Specified Hasegaw'a et ai. (40) estimated that envnonnicntal Chemical Substances, under (he Act for Safety and conditions in caibonlcss copy paper manuf.icttinug Health of Workers, of April 28, 197!) established an facilities (using Kancchlor 300) were i uughly similar occupational environmental exposure limit for to lltose found in capacitor facloncs Beginning in PCBs of 0.5 mg/m3 at 25C71 atm C$3). Japanese im February 1971. PCBs w-cic phased out as the mi- port of PCBs commenced around 1950, and early crocnpsular solvent in this process, being replaced uses were as dielectrics in capacitors and trans- by SAS or KMC-oil; however, during the pcnod I 4 I formcis. In 1954, Knncpafuchi Chemical Industry Co., Lid, started PCB production in Japan, and it was at about tins time that chloracne eruptions from November 1972 to January 1973. when occu pational health suiveys w'ete being pciformcd telattvc tn SAS or KMC-oiI toxicity, PCB concentra t i among vvotkers were first reported. Slightly earlier tions of 0.013-0.4 ppb were mcasuicd in the envi (1953) incidents of changes attributable to PCBs in ronments of these facilities. Genera! cnvnonmental * blood and urine findings among capacitor factory concentrations of PCBs at that time wcic less than wotkers, however, were reported by Hara (39). 0.0005 ppb. and outdoor PCB concentrations i According to an Ad Hoc Committee sponsored around (he facilities were 0.0043 ppb (-A7) and 0 009 Ii by the Japanese Environmental Agency (35). PCB ppb (4/). In an office room where caibonlcss copv concentrations in the air of a Japanese capacitor paper was used, an air concentration l.l pg PCBmi1 factory (where the major PCB constituent was was mcasuicd, and in the carbonless copy paper t `'diphenyl pcntachloride") were found to range storage area of a post office. PCB conccntiations of from 0,37 to 6.75 mg/m1: this was between the years 8,7-21.1 pg/m' were detected (42). t 1953 and 1957, and prior to the date when the The Japanese Minislry, m its Regulations Tor aforementioned occupational exposure limit was Phyxic.il Examinations for the Prevention of Dis* promulgated. The highest concentration was mea toibnnccs due to Specific Chemical Substances I sured where PCBs were heated lo drive out (Oclobet 14. 1971), advised PCB users to examine enhairied/dibsolvcd air. Admittedly, the analytical employ ecs for dci mal and hepatic "symptoms' and # methodology for PCBs in those years was not as then anamnesis, "subjective symptoms" such as t * June 1978 I ' 167 HONS 206395 anorexia mid asthenia. and mine nrobilinof.cn, in the first (pre-employment'.') physical examination, end to "survey" woikmg conditions, blood tests and livci function tests m the "secondary" (periodic ic-T examination, A 1971 notice advised those users of PCBs as hent exchange fluids to per form com pi chcnsi vc health surveillance US), YamamOto {4,1} repented ` positive' findings in 37 employees of 723 (total employment = 706 in 5! establishments) who were given "special'' physical examinations in 1971. Haia (?9) reported a 20-309?- incidence of dermal '`symptoms," consisting of 'distinctfsc hair folli cles" in exposed areas such as the face, neck, and foicarm. and pimplehke skin eruptions of the face and neck, among employees tit a capacitor facioiy that had been in opciniion between 1953 and 1963 (pcnlachloiobtphcnyls, 1953-1957; Kanechlor 300, 1958-on) No other (e g , hepatic) dysfunction was observed, and no quantitative information was re ported in the reference ftom which the preceding report was obtained: however, in a fo!Iow-up sur vey of wotkers in capacitor factories, Hara et al. {44) repotted that one year after the suspension of PCB usage skin findings had become milder, Hasegawn et al. (40) reported on a 1972 suivcy of capacitor facioucs, in which they noted that per sons working in environments that contained 0.2-0.3 mg PCB/m1 (0 02-0.03 ppm) showed der matologic ailments that included "brown ehromodcrmatosis" of the dorsal joints of the hands and fjngcis and nail bed, and "acncform exanthema." Several eases of comedo or acncform exanthema of the jaw, back, and thighs were seen also. These signs wete no longer observed one month after the cessation of the handling of PCBs, In a factory where Kanechlor 300 was emploj ed as a heat exchange medium, the environmental con centration of PCBs was repotted to be 0,02/mg/m3, and no dermal manifestations were observed among its employees {40), Nor did Hashimolo {45) observe any abnormalities among 236 woikers in such a facility, to whom he administered "examination centered around liver function tests," In 1972, when Hasegawa et nt. {40) performed a health survey of workers in carbonless copy paper factories (2 years after the use of PCBs in such pro cesses had ceased) they noted no dermal effects, and no liver function, blood, or urine test abnor malities were seen, with the exception of "slight abnormalities" in lipid metabolism, PCB levels in the blood of these woikers were reported as "ap proximately 0.01-0 02 ppm." or what amounted to * decrease to 10Ci of the lei els dining ihe period of PCB usage. The data indicated that PCBs collected fiom the woik ntinosphcic had apparently degraded 168 to a product containing one less chlorine atom than the average number of chhninc atoms in the PCUs handled in the factory, and that, conversely, the PCBs found in the woikers' blood tom.lined one more clilonnc atom than did the PCBs handled m the factory, i c.. if the PCBs found in the woikeis' blood uerc inhaled nt the workplace, it can he sur. mised that the di- and tiichlorobiphcnyls disap peared inpidly from >hc body, whereas the tetrachloiobiphenyl mis metabolized slowly. Hasegawa cl al. (40) concluded that blood analysis is a feasible method for dcicimining body btudcns of PCBs. and "probably moie useful than the technique presently used by cxtiacting adipose tissue and using it foi PCB,' urinalysis for PCBs did not appeal to them us a viable monitoring method. They noted, however, that there was no correlation between length of employment (and pre sumably, duiation of exposure) and the amount of PCBs accumulated m the blood, i.c . with continued exposure, PCB levels in the blood did not increase linearly: in light of the demonstrated slosv excretion rate of PCBs from the body, the aulhois conjec tured that some different biotransformntive mechanism comes into play after blood PCB levels exceed approximately I ppm (perhaps fat storage). This would seem to belie their confidence in blood analysis as- a reliable index of exposure. Kitamura et ;il (-/<5> icportcd that the mean PCB level in the blood of ten capacitor factoiy workers was 0,82 ppm (0 32-2 1 ppm) immediately after the cessation of PCB usage and 0.31 ppm 3 months later, when almost all of the subjects were observed to have skin signs. It seems significant that the blood PCB concentrations observed in this study were several fold higher than those seen by Hasegawa et al. (40), Kitamura et al. (46) attributed the skin effects to PCBs accumulated in the work ers' bodies during the period of PCB usage. No other abnormalities wete reported. Sagami et al. (47) reported the case of a housewife in whom they observed skin effects several years after she had left 6 years of employment in a capacitor factory. She was found to have PCB con centrations of up to 0.13 ppm in her blood and of 42 ppm in samples her subcutaneous adipose tissue; this contrasted sharply with the findings of Hara et al, (44) that the blood PCB levels of three woikers who remained at the same factory had decreased to 0.05 ppm one year after the cessation of PCB usage [from levels of 0.05-0.3 ppm during the time of PCB usage (-/0)J. Sonic capacitor manufacturers in the U, S. use epo\ide-t\pe alkylating agents :.s additives to pro long the service life of PCBs. 1-PA see. 308 re sponses from the Geneial Hlecttic Co., probably contain identifying data. Environmental Health I'cispcctjvcs HONS 206396 Air ami Water Kxpositrc to PCIis As indicated previously, nominal hum,TM expo sure to PC Us in the U S population m.iy occur from air and water. Samples of ambient air were col lected in suburban areas of Miami, rioridn-, Jackson. Mississippi, and Fori Collins. Colorado. Picii minary results t-VA) foi samples taken m April. May, and June of 1975 show Ihoi PC Us were pres ent at all locations. Although ihc data varied, the average concentrations at each of the three loca'lions was approximately 100 ng'm' Initial identifi cation of the i'CBs indicated that ihey were most comparable to ihe AI odor 125-1 siuudmd Dennis (-JV) has reported that dam gathered from monitoring activities of surface w aters and bottom sediments of the majoi dinmagc basms of the United Slates indicate the widespread occurrence of PCBs in both surface water and bottom deposits, A preliminary assessment of PCD levels shows mean residue levels in water ranged frdm 0 01 to 0,05 ng/i. The 0.05 /ijyl were found in the South Atlantic Slope and Eastern Gulf of Mexico drainage basin. In general, the lowest PCB residue levels were found in drainage basins west of the Missis sippi. Klcmci t (50} has summarized the work completed by the Wisconsin Department of Natural Resources to identify some PCB sources in the environment in Wisconsin, Effluents from cooling water in aluminum foundries contained PCBs ranging front il.5 to 335 ppb. Investigations revealed the com mon source to be leaking hydraulic fluids containing PCBs which were used in die cast machines. Effluents front paper mills that recycle wastepapers has measurable discharges ranging from 0.01 to 25 PPb. Snow samples (.50) were collected early in 1975. Analysis of the snow melt water from Racine, Kenosha, Madison, and Milwaukee revealed con centrations fiom 0.17 to 0.24 ppb. The author con cludes that these values suggest that fulloul of PCBs from the air may be a principal source of PCBs en tering the waters of the state. Hesse f5f) indicates that, similar to the studies in Wisconsin, not all industrial effluents tested in Michigan contain measurable PCB levels. In testing over 900 industrial samples, approximately 40% contained PCBs above the 0.1 ^g.1 laboratory sen sitivity limit. Of the industries tested. 23% had greater than 0.5 n&/1.. 18% greater than I pp.1 , 6% greater than lOpgri .and 2% greater than 100 ^gd. Although much of the PCBs entering municipal waste treatment facilities arc removed and become incorporated into the waste sludge, a sampling of 5S municipal wastewater treatment plant (ffluents thtoughout Michigan in 1973 showed on uvci.igc concentration of 0 52 yjg/J. Conccnir.iiions of PCBs arc much higher in (he sludges. 'Ihe average fui all plants was 15.6 mg/kg wtih indivnlti.il values as high as 350 mg, kg Since sewage sludges arc commonly disposed or by incineration, spreading on ugneultui.il land, or placing in landfills, the adduion of PCBs to the environment is obvious. Residues of PCBs in Human Tissue and Milk Yobs (52) has icportcd that 31 1% of 637 samples of human adipose tissue collected from the gencird population as part of the Human Monitor me Sin \ c v during 1971 were positive for PCBs in measurable amounts. These samples were collected in 18 states and the District ol Columbia and positive samples were obtained from each of the sampling si.ucs and District, The distribution of PCB levels ranged !i om 34 2% none detected, 33.3% < I ppm, 27.3 % 1-2 ppm, and 5.27c >52 ppm. Kutz and Sirassmnn f53) have described the re sults of PCB monitoring during fiscal yeai s 1973 and [974 in which 35.17c and 40.3%. respectively, of the tissues collected contained levels of I ppm or more of PCBs on a net-weight basis. Analysis of the tis sue revealed that ihe compounds found in adipose tissue wcic most comparable to those prevalent in Aroclor 1254 and Aroclor 1260. Additional analysis indicated that the most frequently encountered PCB residues were penia-, hexa-. and hcpiachlorobiphenyl compounds. Residues of PCBs have also been detected m a study of human milk collected in Colorado where 8 or 40 samples contained residues ranging fiom 40 to 100 ppb 154), A study of adipose tissue samples collected at autopsy from Canadians (55) indicates that the majority of Canadians have adipose tissue residues of t to 2 mg/kg of PCB. AH adipose tissues had detectable levels of PCBs and 30% of the samples had PCB residues greater than 1 mg^kg with a range of 0,11 to 6.60 mg/kg. PCB residues in human milk from Ontario residents were found to be approxi mately 1 mg/kg on a fat basis. Polybrominated Biphenyls Introduction and Background The polybromin.ilcd biphenyls (PBBs) in this re port refers to either FireMastcr BP-6 or hevabromobiphenyl manufactured by Michigan Chemi cal Corporation for use as a dame retardant for thermoplastics. This product is a nuxtuic of brominated biphenyls with an average bromine content June 1978 169 *1**' W MONS 206397 equivalent to .ihoul six biominc atoms pci biphenyl molecule. FiteM.iMcr BP-6 is a mixture of the lot. lowing bromin.itcd biphenyls, tcii.ibiomobiphenyl. 2 0%; pcntabromobiphenyl. 10 6%: hexabromobiphenyl, 62 8%. hepUihromobiphcnyl. 13.8%,othci bromobiphcnyls. 11.4%. Tiic Miclngun Chemical Coipornuon has staled 156) thal. to their know ledge. FucM jalcr BP-6 is the only poll hionnnjted biphcnjl produced in com mercial quantity in the U. .S. Their production esti mates arc- 1970. 20.000 lb, [971. 200.000 lb, 1972. 2.300.000 lb. 1973. 3.900.000 lb. 1974 (projected) 4.800.000 lb. Firemaster BP-6 has been used ns a (lame ictardant in the mjnufacnnc oT typewnici. cnlcul.itor nnd micionim ic.ider housings, radio and TV parts, miscellaneous small automotive parts and smalt parts foi clectiical applications. The use of FireMaster BP-6 lias been restricted to those applica tions whcic the end-use product is not exposed to either animal feed or food and there is no known use in flame retarding fjbrics where human exposure would occur. The ultimate disposition of FireMaster BP-6 upon butial is unccitnin. The Michigan Chemical Coiporalion lias slated that in (heir opinion this material will eventually undeigo oxidalive.'biological degra dation foimmg carbon dioxide, water and bromide ion. Human Exposure In October of 1973, adverse health effects were observed in cattle in several dairy herds in the Slate of Michigan At that time, the cattle refused to eat manufactured feed; milk production dccicascd; thcic was a loss in body weight and the cattle de veloped abnoimal hoof giowth with lameness: cat tle and swine aborted, and Burners reported the ina bility to bleed heifers after they consumed feed manufactured by Fntm Bureau Services. A herd of some 100 head of cuttle sent to slaughter during this time pciiod exhibited enlarged livers. Analysis of samples of the suspected feed by laboratories of the U. S. Department of Agriculture at Bcltsvillc. M.nyland. rescaled that the feed was contaminated with a flame retardant chemical, hexabtonunated biphenyl. Subsequent investigation revealed th:i! ihc Michigan Chemical Corpoiation manufactured magnesium oxide, a dairy feed sup plement sold undci (lie tradename Nutri,Muster, and a flame teiurd,i()t. IicxtibiOniinatcd biphenyl, sold under the tradename FireM,aster BP-6 Both of ihcsc products were distributed in biciwn paper bags with cither the name NutriMastcr or FireMaster stenciled across ihc top oT the bag When Ihc top of ihc bag was torn off and discarded, idcnlification was essentially lost. As Ihc result of a nux-up in bags. TireMastcr BP-6 was mixed with animal feed in place of the NutiiMastcr. apparently in the same proportion of use for the NutiiMastcr. It appears that three kinds of feed were initially involved in this episode with PBI3 levels as follows. Feed No. 405, 2.4 ppm PBB; Feed No. 4 10. 1790 ppm PBB. Feed No. 407. 4300 ppm PBB. Samples of milk collected from individual farms soon after Ihc PBB was identified as the contami nant ranged from 2.8 ppm on a fat basis to 270.5 ppm on a fat basis Other producis seized and do st) oyed included: butter (1-2 ppm), cheese (1.4-15.0 ppm): canned milk (I 15-1.62 ppm) Jt has been estimated that between the onset of contamination in the fall of 1973 and the establish ment of the quarantine of affected herds and Pocks in the spring of t974 over 10.000 Michigan residents have been exposed to PBB through the consump tion of contaminated milk, meat and other dairy products. There was ptobably considerable varia tion in both length of expostne and levels of expo sure. As a group, the farm family members have been at greatest risk followed by those individuals who purchased daily products from contaminated farms on a regular basis. In order to determine whether or not persons ex posed to PBB-contaminated products had suffered mil Mood ttvrl, ppm 0 O.OONOOI9 o o:o-o ow 0.100-0 490 0.303-2 260 Total 170 Table 9, Dtstribullon of PRO blood levels, Michigan, 1974, Quarantined farms Adults Children No. % No. % 3 3.7 _ ` 43 32.4 t 2(6 19 23.2 10 33.7 11 13,4 3 10.7 t 7.3 7 75.0 2 too.o 28 too.o Nonquaranlined farms Adulls Children No. % No. 21 32 1 0 0- 2S.4 -- 70.3 29 1.4 1 00 00 74 100.1 30 % -- 96.7 3.3 0 0 1000 Environmental Health Perspectives I" * --a N HONS 206398 Tabic 10- Compailsun offlm cunrcnlrjlliuis In hiimm brtasl milk lid blood pi,mm. Dale 12/74 6/74 1074 3/7 J 3/75 _- . Pill) k rtrcusl milk 10.600 22.700 1.800 0.210 92.660 ppn BUkaI plasma 0.082 0 252 0 014 0.003 1.058 Tlblc II Comparison of THU cono. ntrjllons In human adfpow Unuf and blood pLunui# PBD tcsels. ppm Date Adipose tissue Blood pljsma lt/4 6/74-1/75 3/75 3/75 3/75 3/75 4/75 4/75 4/75 4/75 4/75 4/75 5/75 0.410 t .400 3.000 174 000 0.248 0 274 0.177 0.152 1.(40 0.808 0.530 0.210 l.tIO 0.002 0.005 0.012 1 068 0 002 0.003 0 003 0 003 0 004 0.004 0.007 0.003 0,003 any acute adverse health effects, the Michigan De partment of Public Hcallh undertook a scries of studies in the summer and fall of 1974. Study par ticipants for the exposed group were dairy farm res idents from faims which had been quarantined by the Michigan Department of Agricultutc. The ex posed subjects were limned to those who had lived or worked on the quautntined dairy farms foi more than six months since May of 1973. Nonexposed subjects were landomly selected from a list of dairy producers in the same geographical area where farms had not been quarantined. A total of 298 persons were interviewed in the study and physical examinations and/or blood sam ples were obtained for 110 persons in the exposed group and 104 persons from the control group. The Michigan Department of Public Hcallh has reported (37) that responses to a set of 24 specific medical conditions revealed that none of the health complaints occurred consistently in either of the study groDps, Statistical analysts showed that none of the listed complaints was significantly more fre quent in those persons wiih the highest PGB levels when compared to other study subjects. Physical examinations of adults and children showed no un usual abnormalities of the heart, liver, spleen or nervous system. Urinalyses and complete blood counts did not reveal a significant excess of unusual abnormalities related to exposure to PDl) levels. These .studies showed lh.il blood levels of riJfl were significantly Inglici tn the study subjects from (|u:n,intmed f.inus as cmnp.ircil lo those fiom iho minquaraniincd f.mns. although some subiccls fu>rn the fatm showed low PIJU blood levels liable 9) Several exposed females ildivcied normal babies without complication. Tests showed conecnu.itions of J'BB m breast milk lobe considei.ibty highci limn thai found m piuicd blood plasma (Table 10). Palled samples of adipose tissue and blood were collected in a group of Id individuals entering she hospital foi sutgical ptocedures. 1 lie conecnir.ilion of PBB in adipose tissue i tinged Horn 61 to 370 times the I'BB value found m blood pl.isin.i with an aver age ratio of 175 to I (Table II). Reports of health complaints such as numbness, stomach pain, headache, Tatipuc and anxiclv con tinue 10 be reported m the vuirous new spa pci s m Michigan. Reports have also appeared in the piess that several physicians in Michigan have repoiicd abnotmal liver function tests in patients exposed to PBB. Attempts to venfy these teporls with physi cians have been unsuccessful. REFERENCES t Interdepartment Task Force on PCOs Polychlorinated hiphenyls and % environment Washington. D C 1972 2. Jetmek, C. F , and Corneluisson, P E l.r\rts ot t'CUs in ihe LI S food supply. Paper presenied el Njiionat Conference On rolychlOOthilcd Uiphcnyts, Chicjpo 1975 3 National Purchase Di.ny iSch.ntmherE. Ill ) and NXiFS. Seafood Consumption study, 1971 197-1 National Marine fishenes Service--NOAA U. S Department of Commerce. Washinflnn, D C . 1976, p 146 4 Nanou.it Marine Fisheries Service iNMfS) Compendium of PCB dulu National Marine fisheries Service--NO A X U S. tt.'parlmenl of Commerce, Washington, D C , I9`6 J. New Yoih Slate Department of Cnsiiunment.' Analyses. NYDE. I'CB residues in fish New York Slate Department of Environmental Analyses. Alhanv, N Y . I97J. p |47. 6. NMFS Survey of fish purchases. 1969 7. DREW.`I cn-state nutrition survey. 8. I-IM Market Basket Survey. 9. Snort Fishing Institute. 10. Texas A & M Analysis or seafood consumption patterns in Texts. 1974. It. Humphrey.ll E. B , Price. H. A., and Dudd. M L. F'alu ation of changes of the level of polychlorinated biphensts tPCBs) in human tissue, rm.il Report of FDA Contract No 223-73-2209 1976. 11. Kltratsune. M, Paper presented at National Conference on Polychlorinated Biphenyls'. Chicago', Nov 19. )975 13. Kuratsilne. ht,, ct at l`pktcrmolbpe' studs on Ynsho, a poisoning caused by mpestwni ol ru e oil coniaimnaied mill a commercial bi- and polych1onn.ited biphenyls Lttmon Health Perspeci. I: 119 11972). 14. Kuialsimc. M.. et at. An epidemiologic study on Yushn or ehlorobtphenyls poisoning. Fukuoka Acm Med 60 Jl) ll%9). June I97S ' 171 MONS 206399 |J, Yushimiira. T, Epidemiological analysis of Yusho patients wi(h special rtfercncc to vex, age, cluneal grjucs and oil consumption. I uknokrrActa Med. 62 i&4 (1970 16, Kunitsiuic. M. An abstract of results of laboratory exuminn- lions of patients with Yusho and ornnim.it experiments En viron Health I'crspect I '120 f 1972), |7. Kuratsunc, M , el at. A poisoning caused by rice od eon. laminated with polychlorinated biphenyls HSMHA Health Rrpl. 60, 1083 (1971) |8. Tsukamolo, M . el id The chemical studies on detection of Idxic compounds in the rice br.in oils used by the patients or Yusho. Tiikuoka Acta Med 00 496 1)969) 19 Nognyiim;], J,, M.isinJ.i, Y . and Kuraisune. M, Chlorinated dilientofurans in K.mcchlors and nee Oils used by p.ilicnts with Yusho rukuuk.i Act.i Med. 66 J93 11975). 20, Oeme. 1, Foreword fifth report of the study on Yusho and PCIS (polychlorinated biphenyls), Fukuoka Acu Med. 66 547 (1975) 71. Nagayama, J , Masuda. Y,. amt Kuratstinc. 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E., and Gaines, T. 13 Mor phological changes m livers of rats fed polychlorinated biphenyls. Arch Environ. Health 25. 334 (1972). >0. Kimbrough. R. D , and Linder, R E. Induction of adenofibrosis and hepaiomas of the lis'er in BALB/cJ mice by polychlorinated biphenyls (Aroclor 1254). J. Nati, Cancer lnil, 53: J47 (|974|. 31. Poland, A P,, ct al, A health survey of workers in a 2.4.D and 2.3,5-T plant. Arch. Environ, Health 22; 316 (1971). 32. Crow, K, D. Chloracnc. Trans. SI. Johns Hosp- Dermal. Soc. 56; 79 (1970). 33. NIOSH. In press. 34. Karppamcn. E., and Kolho. The concentration of PBC in human blood and adipose tissue in three different research groups. PCD Conference II. Vallingby, Sweden 1974, Na tional Swedish Environmental preelection Board Publication 1974 , 4E. . 35. Joint 1LO/WHO CommtUee on Occupational Health. WHO Tech. Rept. Senes No. *J5, 196ft. , 36. Ovw, K. 11.. Simpson, O. R., and Siyali, D.S. The use and health effects of Aroclor f&IZ. a polychlorinated biphenyl in *n electrical industry in b& S. W-Australia Report. Div of Occup. Health and Radiation Control. Health Commissions of New Souih Wales. Australia. 1974. 37. Australian National Health and Mcdie.nl Research Council. Atmospheric contaminant*. NHJMRC. Canberra. Auslralta. 1970. 38. Ad Hoe Commuter of Jap-m Public Itc.illh Association r,n, viroumeni.il hc.illh criten.i for po1yehli>rmulcsf ht- and ler. phenyls Environmental Agency of J.ip.uvWllo Environ mental llsalth Cnleru Programme. 1974 39. H:ir.i, 1 Hcuhli supervision of workers exposed to chluiobtplienyl in nn ikcine condenser factory. Proc. Osaka Prefec! Inst Pub Health Ed Ind, Health 7 26(1969), 40. H.ivcguwu J , Sato M , and 1 surula. II Report on sutvev of work area environmental where PCI) is hantlled and of the health u orkers liandhnc PCI) Ministry of Labor, tluf eau of Lalior Standards and Institute ofinduxtiul Health, Republic or Japan. 1973 4 1. Sato. M., and llascgavva H PCH concenlrntions in the blood Of workers employed in carbonless copying paper production Japan J. Ind Health 16 165 (1974) 42. Nishiymn, K., Yano H , and Katnann, M. Determination method for poljchlorobiphen)I in tnr and its vaporization from non-carbon copy pupet Shikoku Acta Med 29 305 (1971) 43 Yamamoto, H Statistic] of occupational disease Iresull of special medical examination), In' New Occupnm-nal Health Handbook 1010 I0IJ. The Institule for Science of Labor, Japan, 1974, , 44 Ilara, I.. et ftl Follow-up hcnllh examination in an electric condenser factory after cessation ori'CUs usage (Isl report) Japan J lnd. Health 16 365 (1974) 45. Hashimolo. I Liver function lesl results of PCD influence checkup. Japan J Ind Health 47 264 (1974) 46. Kitamiiru, M,, ct at. The FCB levels in the blood of workers employed m a condenser factor. Japan J. Ind. I lealth 47; 354 (1973). 47. Sagami, S , Kamat*. S.. and Yoshida. M A case of chronic PCB-mtoxication Ntshmifton llifuka 16 694 (19731. 48 Kutz, F. W.. and Yang, H S- C A note on polycldorinatcd biphcnjls in air. Paper presented at National Confeience on Polychlorinated Biphenyls. Chicago, 1975, 49. Dennis. D, S Pols chlorinated biphenyls in the surface sva. left and bottom sediments of the maior drainage basins of the Unites States. Paper presewed at National Conference on Pol;chlorinated Diphenyls, Chicago, 1975 50. Kteinerf. S. J. Sources of polychloiiNuicd biphenyls in Wis consin Paper presented at National Confctence on Polyshlonoated Biphenyl*. Chicago. 1975 51. Hesse, J, L. Polychlorinated biphenyl usage and sources of loss to the environment in Michigan Paper presented at Na tional Conference on Poly chlorinat'd Diphenyls, Chicago, 1975. 52. Yobs, A. R. Levels or polychlorinated biphcnvls in adipose tissue of the general population of the nation. Environ. Health Pcrspcct. I: 79(1972). 53. Kutz, F. \V.. and Strassman. S. C. Residues of polychlori nated biphenyls in the general population of the United States. Paper presented at National Conference on Polychlorinated Diphenyls. Chicago. 1975. 54. Savage, E, P-. et al Organochlorinc pesticide residues and polyehlonnated biphcnvls in human milk in Colorado, 197). 1972. Pcslie. Monitoring J 7- I (1973) 55. Gram. D. L .Mes.J .ansirrank, R PCB residues in human adipose tissue and milk Paper presented n( National Con ference on Polychlorinated Biphenyls. Chicago. 1975 56. Michigan Chenus-il Companv, Renew of polybronunated biphenyls Presented to the Michigan Environmental Review Board, September 1974, 57. Michigan Department of Public Health Report, 1975. 172 v Emirontncnljil Health Perspectives T If,,' --vg'T HONS 206400