Document rB9QzpQvN2Vzg6g7qyyKVvy9G

cc cr. lot XVZ.H - Lpdr vj/ashmofcn BulleHn f. 4****** vP JJAT/QNAL PETROLEUM REFINERS ASSOCIATION FfutidrA 1902 SUITE 602, 1725 DESALES STREET. N.W., WASHINOTON. D. C. 2003# TllCt-HOMl 1*0*1 *J9711 Jonuory 7, 1977 For the pair several monfhj, the Occupational Safely and Health Administration has been urged by the Notlonol Institute for Occupational Safety and Health to reduce the permissible exposure to benzene to the lowest feasible level based on o claim that benzene is leukemogenic, pro ducing progressive, malignant diseose of the blood-forming organs. NIOSH, established under the Occupational Safety ond Health Act to function os o reseorch entity, has strongly advocated that on emergency standard of 1 ppm be established until the present exposure level can be revised through the normal administrative processes. Current regulations ollow occupational exposure to o 10 ppm time weighted level .with a ceiling of 25 ppm ond a peak of 50 ppm for no more than 10 minutes per 8 hour day. The 1 ppm stan dard recommended by NIOSH would be based on somples collected at 1 liter of otr per minute for two hours. There have been reports that an emergency standord has been advo cated by the United Rubber Workers and it Is likely that the Oil, Chemical and Atomic Workers Union will eventually become involved in efforts to lower exposure standards. Thus for, OSHA has resisted efforts to Implement on interim 1 ppm standard, but It Is understood that a "guideline" recommen dation has been prepared for OSHA Administrator, Dr. Morton Corn's signa ture, but his intentions-and tenure at OSHA are undetermined. The legal fricocy of a "guideline" which is not covered in the Act is somewhat in doubt. Benzene Is, widely used, most notably as a solvent, but also Is contained in many petroleum products. Some companies hove reported that a I ppm standard may be exceeded by some degree in areas involving handling, 00 06803? CONFTOFNTTAl received FFB 1B 1977 llmmhs 00284 D 00970 YZ00SS001 Poge Tw shipping ond fromfor fbonzene. There have been claims that, under certain 1 conditions, retail dispensing operations of gasoline containing bonzene expose motorists or attendant^ to levels above 1 ppm. Such a claim was voiced by he Environmental Defense Fund, at a hearing sponsored by the Environmental ^ H**otetfThn Agency on Jonuary 5, 1976 concerning the implementation of vapor recovery systems at retail service stations. EDF's testimony Included state ments that.. ."gasoline evaporation is a major source of benzene emissions," ond.. .a larger percentage of this evoporotion occurs during the refueling of automobiles." Criticizing EPA's "foilure to oddross the significant heolth hazard," EDF pointed to the growth of self service gasoline service stations ond the fact that vapor recovery systems ore required in 13 air quality control regions at about 15% of total U, S, service stations. A statement presented by the American Petroleum Institute took Issue yrfth efforts to link benzene with leukemlo, noting that a connection "hod not been proven or established on a sound scientific bosh." While conceding that toxic effects of high levels of benzene hove been recognized for decades, the statement made the obvious point that toxic effects are readily prevented by controlling benzene levels to present allowed levels in the workplace. Numer ous studies within the petroleum Industry, and notably one involving dota on 1,100 deaths among 20,000 refinery workers with on average work history of 20 years, have not revealed any evidence that benzene is a couse of leukemia. In fact, tn this particular study, fewer deaths were related to leukemia than normal experience in the general population. Refinery operations should pr vide a convincing test since many refinery process streams contain behzen , often in concentrations far above those in gasoline. While the regutatoiy agencies ponder the necessity for stricter benzene exposure standards, other concerns hove arisen out of the allegations linking benzene with leukemlo involving potential liability as a third party In civil damage proceedings. While employees generally ore limited in recovering damages from their employer outside of Workmen*! Compensation legislation, there is no similar constraint on recovery of domoges from the employer's supplier of a substance deemed to be responsible for injuries or death. Some companies are considering distributing literature warning all recipients of their products containing benzene of its dangerous propensities, but the effect of such a warning is questionable. NPRA has endeavored to apprise member companies' safety personnel f OSHA's activities on bonzene exposure levels through Its Fire ond Accident. Prevention Bulletins and regional Fire and Accident Prevention Croup m etings, but it would oppear that benzene exposure may soon become another contro versial environmental Issue. DO 068033 CONFTDFNTTAl O OOS^i YZ0058002 DOW CHEMICAL U.S.A tomsdmmmom (WWMT, TVXAM TM41 June 10, 1983 Dr. Carol Slack Chemical Manufacturers Association 2501 M Street, N.W. Washington, D.C. 20037 Dear Carol: Enclosed is the benzene exposure survey for Dow Chemical Company. If I can help in any way with problems of compilation please give me a call. Very truly yours, dap Enclosure R. L. Daniel Environmental Health Services 02644 AN OSSMATINa UNIT OT THB DOW CHEMICAL OOMSANV 00 068034 OONIF TDFNT TAt YZ0009845 benzene exposure survey -- Indicat# Category! ProducerV User_ Industrial Hygiene Guideline (a) Docs your company have an internal industrial hygiene guideline (exposure limit) for benzene? Yes No Xf yes. What is it? - HR. TWA fffppyvI - Ceiling limit .2 Producer/Processor Facilities Handling Benzene (a) Number of locations with employees with possible exposure to benzene of 1 ppm TWA or greater .3 . (b) Total number of facilities (departments, plants, etc.) with^employees with possible exposure to benzene of 1 ppm TWA or greater. 3. Number of employees with possible exposure to benzene of 1 ppm TWA or greater, (a) Routine* Basis (b) Intermittent** Basis j*r* * Routine means 3 or more work schedules per week. ** Intermittent - 2 or less work schedules per week. 4. Exposure Profile - TWA and Peak Indicate number of employees per category. TWA,PPM PEAK,PPM 1-3 4-7 8-10 10-25 > 25 tz NOTEi Individuals can be included in both the peak exposure category as well as the TWA category. All employees in 3(a) and 3(b) should be accounted f r in this profile* 5. Respiratory Protection (a) Is your company using respirators to control employee exposures to benzene? Yes_____ V______ No__ If yes, is application! Routine Xntermitt nt Both X ^Trai YZ0009846 I (b) Indicate Uiki type respirator# numbers of employees using routinely and Intermittent^^* TASK TYPE RESPIRATOR* ROUTINE INTERMITTENT JSL M AP _____ 32. 8CBA#'Airline, Air Purifying (nose-south or full face). (o) Is fit tenting performed? Yes % Mo Xf yes# indicate type of fit testi Qualitative Quantitative X (d) Are respirators used to control exposure to bensene of contractor pers nn 1 on your premises*? Yes X HO Xf yes# is application! Routine Intermittent 1 Both X_______ * Include barge loading/unloading (e) Indicate taeh# type respirator# nuaber of contractors using routinely and intern!ttently TASK rapir?- TYPE RESPIRATOR AX ROUTINE INTERMITTENT ____ &2_. 6* Engineering Controls (e) Is your company presently using engineering controls to alnlnis* bentene exposure? Yes DO 068036 CONFIDFNTTAl YZ0009847 T . s'",!** * (b) fcngineering control* 1* u**i Automatic leak detection systems Doable Mechanical seal* ,,-Double seatod valve* . Local exhaust system** . . Special sample point*_ Vapor recovery aystame Other (specify) ^ X ^ y ^ )( ' * Exclude laboratory'fume hoods 7. Administrative Controls Doe* your company use administrative scheduling of work assignments to limit employee exposure to benzene? Yes Mo X Training Zr-there, an established formal training program for employees with possible exposure to benzene? -r.c. 11 -Supervisorst _____ Workers Medical Surveillance Yes Yes Mo No (a) Are pre-employment physical examinations available for all employees with possible exposure to benzene? Krr- Irciv:-.: . 1- Yes- \ Mo - Zf yes, ara they mandatory? Yes X ,,Q (b) Are pre-employment physical examinations mandatory for those workers who may be directly exposed to benzene? l:Yes_ JU Mo rnwc-068037 CNF70 FNTTqi YZ0009848 (c) Which of the following sre Included In the pre-employment phyalceli Occupational Klatory ______ X. Family hietory (blood dyecraeias) ______ ^ Personal history (complete) ______ CBC with differential Platelet count Hematocrit Hemoglobin X X XX Red oell indices (MCV, MCH, fi MCHC) ^ Serum bilirubin X Reticulocyte count X (d) Are periodic physical examinations available for all employees with possible exposure to benzene? Yes X Ho Xf yes, at what frequency are they offered? If frequency is age-adjusted, please specify* Are periodic physical examinations mandatory? Yes_____________ Ho X_______ (e) Which of the following are included in the periodic physlcali Occupational history update t Personal history (complete) X \ CBC with differential X Platelet count V Hemoglobin X Hematocrit X (f) Do you periodically update medical history and perform clinical laboratory tests excluding hands-on physical examination? DO 068038 Yes X______ N ____ ______ C0NFT0FNTTA1 If yes, specify frequency. (Tty. AmiwJK. - othfr* Ws. n.l\ L. Ir/it xi/>Mi 1tiX'VMfZ*, YZ0009849 (g) ^Xre Imy^biologlcal tests ased for removal purposes? ;se : Ho X _________ "if yesVexplain* ...... . * ** * ' * <h) Do you use urinary phenols for* (i) routine Monitoring X (ii) emergency exposure Monitoring______ X. fili) : neither of the above_____________________ Xs_ adjustment made for specifio gravity? 'if yesV state value t /. - h Are r*;r *vi* YZ0009850 RECEIVED M AY ? t 1983 Bethlehem Steel Corporation BETHLEHEM. PA 1*016 Dr. Carol Stack Manager - Benzene Program Chemical Manufacturera Aaaociatlon 2501 M Street, N.W. Washington, DC/ 20037 Dear Dr. Statk: Kay 27, 1983 For Dfisctributkioan tnr CMA IRCIAL RO0ORMA!MI DIVISION Epqim Ci.. yS77?<rr'< Ref. No. Date___ %/cS(CJ /Ttyntj'L./**"*- ' T dtffa Re! Benzene Hematology Study Attached for the information of the Benzene Program Panel is a copy of a study entitled "Hematological Findings Among Workers Exposed to Benzene at a Coke Oven By-Product Recovery Facility", which Bethlehem recently submitted for publication. As you may recall, Gary Hancock summarized the remilts of this study at the March 15, 1983 Panel meeting. This study was also presented at the May 21, 1983 Spring Syoposlum of the Mid-Atlantic Chapter of the Society of Toxicology held In Wilmington, Delaware. We tentatively plan to submit this report as new information into the hearing record of any future OSHA rulemaking activity on benzene, either independently or through our trade association, the American Iron and Steel Institute (ATSI). Please contact Gary Hancock directly at 215/694-5105 with any comment a or questions. Sincerely yours Attachment cc: P. A. Hernandez WCEIVEB JUN 61993 SEMINS DO 068040 CONFTDFNTIAI YZ0019781 HEMATOLOGICAL FINDINCS AMONG WORKERS EXPOSED TO BENZENE AT A COKE OVEN BY-PRODUCT RECOVERY FACILITY iv* im mm -- D. Gary Hancock, M.S. Augustine E. Moffltt, Jr., Sc.D. Bethlehem Steel Corporation Environmental Health Division Bethlehem, PA 18016 Errol B. Hay, BECHE Bethlehem Steel Corporation Environmental Control Sparrows Point, MD 21219 ABSTRACT Hematological findings on a population of 70 male workers expoaed to benzene revealed no significant differences when statistically compared t a set of 21 controls on the basis of estimated cumulative doses using snalysls of variance (ANOVA) and only one significant difference using Student's t~test. The hematological data evaluated included the following parameters: red blood cell (RBC) counts, white blood cell (WBC) counts, and hemoglobin (Hb) levels. Cumulative benzene exposure Indices for each employee were estimated utilizing available personal monitoring and general air sampling data, as well as the professional Judgment of local environmental health engineers familiar with the operations. Although the accuracy of these exposure estimates Is unknown, the results provide no evidence that the present OSHA standard (10 ppm) Is inadequate with respect to the non-leukemogenic, hemstotoxlc effects of chromic benzene exposure. IHTRODPCTION The hematopoietic system has been shown to be a major target site in chronic human benzene poisoning.1"4 Observed blood abnormalities associated with benzene exposure Include leukopenia, throob cyt penis, DO 06.8041 CONFTDFNTTAL YZ0019782 - 2macrocytosls, aplastic anemia, and leukemia. Moat of these effects, however, have developed In Individuals exposed to relatively Intense benzene levels (100 ppm) while the significance of low level exposures to the risk of incurring such conditions is largely unknown. Moreover, very little dose-response Information la available on the hemstotoxlclty of benzene. The objective of this Investigation was to assess the hematologic t- status of a population of workers In relation to their cumulative benzene exposure during a portion of their employment history. If benzene does indeed adversely affect the blood parameters at the chronic exposure levels examined herein, It would be expected that different doses would produce different degrees of hematologic change in accordance with classical dose-re sponse relationships. Consequently, statistical analyses were performed to determine whether any such dianges could be discerned among exposed employees. MATERIALS AND METHODS Exposure Levels end Environmental Conslderstions The study population consisted of 70 males who ere presently or were formerly employed at the Coke Oven By-Product Recovery Facility (also referred to as the Coal Chemical Facility) of an Integrated steel plant. Job hletorles of these workers between the years January, 1957 September, 1977 were acquired from company records end used to ascertain work sites and employment positions during this period. Ihle information 00 06804? CONFIDENTIAL 1 YZO019783 -3. viM^subsequentl^utlJ.isedLln estimating cumulative--benzene exposures for each employee. The Coal Chemical Facility Is an operation primarily Involved with the collection and refining of volatile aromatic hydrocarbons from nearby coking processes. Such compounds, which among others include benzene, toluene, and xylenes, are present as by-products In the coke oven gas generated from these processes. This particular facility Is geographically separated Into the following five production areas: add plant, plant A, plant B, light oil plant, and benzene plant. Plants A and B are Involved with the production of primary light oil (a mixture primarily composed of benzene, toluene, and xylenes) while the add plant (which Is no longer In operation) was the site of sulfuric add production. Each employee In the Coal Chemical Facility has s distinct job classification based on the production site and the specific nature of the job function (e.g., saturator operator - plant A). In estimating cumulative benzene exposures for the subject worker population during the approximately 20-year study Interval, information on benzene levels was obtained from Industrial hygiene survey data and from estimates baaed on discussions with plant environmental health engineers. Industrial hygiene survey data consisted of both time-welghted average personal monitoring (l.e., breathing zone) and general air sampling values; however, these data were only available for the last two years (l.e., 1976 and 1977) of the investigation. Furthermore, the aforementioned data did not cover all Job elaself1cations (l.e,, employee positions) or all production areas, but was rather limited In scope. Personal monitoring data was available for 27 of 48 employee positions. 00 068043 CONFIDENTIAL. YZ0019784 -4yljlle general ^*lr -g^jpplAng had only been performed In 3 of the 3 production areea (Table 1). Consequently, many of the beocene exposure level calculations were based on estimates provided by plant environmental health engineers. Since the Coke Oven By-Product Recovery Facility had not dianged dramatically between 1957 and 1977, the engineers recommended that the more recent personal monitoring and general air sampling data could also be r. generally applied to job classifications and production areas, respectively, for the entire study period. When no personal monitoring data for a specific employee position were available, general air sampling data were used. If the letter were also not available, estimates of average benzene levels (as provided by environmental health engineering personnel) for a particular production area were utilised. In eome instances, a number of employee positions (e.g.. General Goal Chemical Turn Foreman) were not associated with a specific production area, hut rather Involved job duties at all five coal chemical plants. As a result, an average of the benzene levels at the five major sites was used In computing cumulative benzene exposures for Individuals who had such work experiences during their employment history. In addition, some employees In the study group did not always work at the Coal Chemical Facility during the 1957-1977 period (e.g., some worked elsewhere In the coke plant for part of their work history); however. In these cases, previous work site exposures were estimated by local environmental health engineers to be about 0.1 ppm. Cumulative benzene exposures were expressed as ppm-nonths. The rationale for the selection of 'ppm-months' as the cumulative benzene exposure Index la essentially the same as that given by Mazumdar at el.5 DO 068044 CONFTOFNT1 YZ0019785 ............................................. .... I -- .M --..... Table 1. - Bentene Levels Associated Vith Different Production Areas Within The Coke Oven By-Product Recovery Facility Production Area Benzene Levels (ppm) Acid Plant Plant A Plant B Benzene Plant Lltol Plant 0.1* 1.9* 1.91 31.5t l.Bt * Estimates based on discussions vith plant environmental health personnel. t Based on 1976 and 1977 general air sampling data (time-weighted average). DO 068045 CONFIDENTIAL YZ0019786 for_ coal tar pitch ^volatiles exposures among coke oven workers; *>**.* ^ WS^"" specifically, both concentration and duration of exposure ere considered to be important factors in the development of chronic benzene poisoning. The calculation of the cumulative benzene exposure index is as follows: Cumulative Exposure Index / __/ [Mean Level Exposure*] x [^Months at Jobl L of mb j[ j jdbs * Mean benzene exposure levels for all jobs were also computed for each individual by the following equation: Mean Level of Exposure * Cumulative Exposure Index (ell jobs) Total Months (all jobs) The employment period (and therefore exposure time) among exposed workers during 1957-1977 study lntervel varied with a minimum of 30 months, a maxluim of 249 months* and an average of 207.4 months. Cumulative exposure Indices for benzene ranged from 11.7 to 26*898 ppm-months with a mean of 2026.9 ppm-months* while mean exposure level values varied between 0*1 and 167 ppm with an average of 10.5 ppm. Analysis of Hematological Pate Hematological data has been collected annually on workers st the study facility since the early 1950s. Thsse dsta generally Include values for such parameters as rad blood cell (RBC) counts* vhite blood cell (WBC) counts* hemoglobin (Hb) levels* mean corpuscular.volumes* platelet counts* hematocrits* and others. Most analysts were conducted by outside laboratories* although some limited teats have been performed ln-house. DO 068046 CONFIDFNTTAl. YZ0019787 -fi ll) order to evaluate the effects of chronic benzene exposures on the human hematopoietic system, certain blood parameters' (l.e., WBC counts, RBC counts, and Hb content) of the study group were statistically compared to those of a control population. With regard to temporal aspects, two seta of blood values, average and most recent, were used for each hematological parameter of each atudy employee during the 1957-197? Interval In making the statistical comparisons. Kean values would be ! Influenced by hematological effects manifested over any part of tha entire study period, while the most recent values would be useful for detecting any lutent or chronic effects of benzene without being diluted or "normalized" by previous normal or typical blood parameter values as might occur with the use of average values alone. The control group consisted of 21 male supervisory employees located at the study operation for idiom hematological data had also been collected during the 1957-1977 Interval. Since these supervisory personnel did not hold positions In the Coal Chemical Facility, the cumulative benzene exposures for controls were assumed to be zero. For the purpose of comparing the possible effects of different dose levels, the 70-menber exposed group was divided Into three cumulative exposure categories: < 240 ppm-months (low), 240-2400 ppm-months (Intermediate), end > 2400 ppm-months (high). These particular quantities were selected for a nunber of reasons. First, it Is important to note that the low, lntermadlate, and high exposure categories are mathematically equivalent to average benzene levels of <1 ppm, 1-10 ppm, and >10 ppm, respectively, for a 20-year employment period. Since e 1.0 ppm permissible exposure limit (PEL) wee promulgated by the Occupational Safety end Health Administration (OSHA) on February 10, 1978, nO 0bR047 CONFIDENTIAL. YZ0019788 but was subsequently Invalidated on July 2, I960, by the U.S. Supreme Court and because 10 ppm la the current OSHA PEL., these exposure categories are important from a regulatory perspective. Although not all employees worked In the Coke Oven By-Product Recovery Facility for the entire study period, these different dose level* can nonetheless serve as a crude basis for making statistical comparisons. In addition, _ select! n of these expo sure categories was such that sample sices were sufficiently r large ao that any significant hematological differences could be detected with relatively good sensitivity. Analysis of variance (ANOVA) wea used to determine If statistically significant differences were present in any of the hematological parameters under Investigation. ANOVA testa the null hypothesis that there Is no difference In the mesne of the populations from which separate samples have been drawn. In this case, four populations axe Involved, three different exposure groups and the controls (or the zero exposure group). In addition to AKOVA, Student's t-teats were conducted on each exposure group versus control group for each hematological parameter examined, both most recent and average blood values. The t-tests were performed In order to determine If there were any significant differences between each exposure group and controls that might have been missed by ANOVA which only teats whether significant differences exist among the means of several sample groups. Even though the results were not age-adjusted, the findings of Fredarik Indicate that age-related differences in the blood parameters examined are very small. 00 Oft.8048 CONFIDENTIAL- YZ0019789 & ttSVLTi_____ r- ^ - - 8- Statistical analyses of the data via AKOVA revealed no significant differences anong the various exposure and control groups at P <0.05 for all of the blood variables examined. Tables 2, 3, and 4 statistically depict henatological data for WBC counts, SBC counts, and Hb content, respectively. Statistical' analyses of the data via Student's t-tests also Indicated no significant differences between benzene exposure groups and controls except for tbs intermediate exposure group with respect to the most recent white blood cell counts which was of borderline significance. However, this exception seems to be due to an unusually low average WBC coint (i.e. 6.4 x 103 cells/sm3 ) for the control group rather than a high value for the exposure group (l.e., 7.4 x 10 cel Is/no ). This Is supported by a mean normal WBC count value given by Lewia^ as 7.811.5 x 103 cells/sm3 . In addition, since this wss the only exposure group to exhibit a significant difference, further Credence is given to the suggeetlon that this was a spurious result caused by the chance event of abnormally low control group value. Because of the lack of significant differ encss (with the aforementioned exception) among and between exposure and control groups, no statements about dose-response relationshipa can be made regarding these benzene exposure levels. Consequently, it appears that th estimated cumulative exposures examined In this Investigation represent dosee which fell below the threshold at which non-lsukemogenlc, hemetotoxlc affects on humans axe manifested, at least in adult males. Although the accuracy of these exposure eatimetea la unknown, the results nonetheless Indicate that the benzene levels experienced by these groups OO o YZ0019790 "' 1 ' 11,1 1 I'll " I"*....... --V Table 2. - Group White Blood Cell Values In a Population of Hale Goal Chealcal Facility Workers, Exposed to Various Doses of Benzene Benzene Exposure Group (ppm - months) 3 3* WBC Values (x 10J cells/nm ) n Averecte Most Becent Control <0) 21 7.6 1 1.1 6.4 t 1.4 Low ( < 240) 17 7.7 1.6 7.3 2.2 Intermediate (240-2400) 37 8.3 t 1.9 7.4 1 1.8 t High ( >2400) 16 8.0 1 1.2 7.1 t 1.4 * Normal Clinical Range 4.9 - 10.7 x 103 celle/mm3. t Significantly different from control group at the P < 0.05 level. DO 068050 CONFIDENTIAL YZ0019791 Table 3. - Croup Red Blood Cell Value* In a Population of Male Coal Chemical Facility Workers,, Exposed to Varloua Doaes of Benrene Benrene Exposure Group (ppm - monthe) Control (0) low ( < 240) Intermediate (240-2400) High (> 240) 6 ** BBC Values (x 10 cella/mm ) n Average lioat Recent 21 5.0 1 0.3 5.0 t 0.4 17 5.1 t 0.2 5.1 1 0.3 37 5.1 i 0.2 5.0 t 0.5 16 5.0 t 0.3 4.8 0.5 * Normal Clinical Ranged 4.6 - 6.2 x 10^ cells/ma^. DO 068051 CONFIDENTIAL YZ0019792 f . "W '*<* Table 4. - Group Hemoglobin Valuea In a Population of Hale Coal Chemical Facility Workers' Exposed to Various Doses of Benzene Benzene Exposure Group (ppm - months) Control (0) Low ( > 240) Intermediate (240-2400) High ( < 240) Hb Values (grems/lOOml Whole Body)* n Average Most Recent 21 15.2 t 0.7 15.7 1.0 17 15.0 * 0.5 15.4 t 0.7 37 15.1 t 0.6 15.4 1.2 16 14.9 0.8 15.4 t l.l * Normal Clinical Ranged 14.0 - 18.0 grams/lOOml whole blood. DO 06^05p cONF YZ0019793 of employees were not of sufficient intensity and/or duration to produce ^`'V* ^ vTM- demonstrable effects on the blood parameters examined regardless of whether the estimated doses are low. Intermediate, or high. DISCUSSION Most bcnsene-related hematological effects In humans have been observed In <occupational populations exposed to relatively high concentrations of bensene, 8-10 Although hematotoxlclty has been reported In workers after long-term occupational exposures to bensene at concentrations as low as 20 ppm, the representativeness of these relatively low exposure levels remains suspect due to the Inadequate monitoring frequency of affected Individuals. In most Instances, however, adverse hematologic effects In Industrial populations have only been noted In employees exposed to bensene levels greeter than 100 ppm on 3 either a short-term or long-term basis. Whether chronic, low-level bensene exposures can also damage the human hematopoietic system cannot be stated conclusively at this time, but the resultB of this study are consistent with the existence of a threshold for nan-leukemogenlc, hematologic Insult. The results further suggest that the quantitative level of this threshold is in excess of the typical exposure levels observed In this study, yet due to the limited amount of personal monitoring data for most of the employee positions Involved and the crude exposure estimation procedure employed, It would be inappropriate to estimate the value of such a threshold. Nevertheless, these results provide no evidence that the current OSHA permissible exposure level of 10 ppm Is Inadequate to protect employees against the non-leukemogenic, chronic effects of bensene on the hematopoietic system sines the average o0 YZ0019794 txposuire dur*tJLon study population was sufficiently long for any such effects to become aenlfest If, In fact* they were occurring. Based on the results of this and previous studies we believe this interpretation or conclusion to be reasonable despite the relatively small simple sizes and limitation to the three hematological parameters examined In this Investigation. The choice Qf RBC counts, WBC counts, and Hb content aa blood test parameters was based on previous Investigations demonstrating changes (usually decreases) in their values during chronic- benzene Intoxication. Moreover, Vlgllanl and Porni 12 have suggested that leukemia associated with benzene exposure is often preceded by s hypogeneratlve anemia or pancytopenia (l.e., depressed production of thlte cells, red cells, and platelets by the bone marrow). Xn an Investigation examining health data among a group of 282 employees exposed to benzene In three different chemical production areas, Townsend et al. 13 obtained results similar to those of the present study. These authors examined various blood chemistry and hematology parameters for the exposed group (compared to mat died controls) with respect to latency, duration, current intensity and cumulative dose of benzene. Although statistically significant raductlona were noted among exposed employees for total bilirubin and RBC counts, the decreases were slight snd not regarded as 'clinically significant'. Xn addition, none of the hematological variables examined were significantly correlated with any environmental variable, even though significant blood chemistry (e.g.. DO 068054 CONFTOFNTI81. YZ0019795 - 11 BUM levels) differences were found In some production sices. Such differences, however, may have been Influenced by exposure to other chemicals present In the work environment (e.,g, chlorobenzene). Since the benzene exposures experienced by the workers in the study of Townsend 13 et el, are comparable to those estimated for the employees Included in this Investigation, the similarity of results Is particularly noteworthy. In contrast, significant results were observed by Greenburg et *1. and * other Investigator* regarding a ttiaaber of blood parameters; yet the benzene exposures present In these studies were, as stated earlier, considerably more Intense. The difference In hematologic responses observed In these various Investigations appears to be related to the benzene dose and Is consistent with the existence of a possible threshold level for non-leukemogenic, hematotoxic effects. o0 O68O55 Cq^tofNTtal YZ001J796 REFERENCES ' i'.'Ha Clouet -iWJtituTe for Occupational Safety and Health (NIOSH). 1974. Criteria for a Recommended Standard...Occupational Exposure to Benzene, Pub. Ho. 74-137. Department of Health* Education* and Welfare, Washington, D.C. 2. National Research Council. 1976. Health Effects of Benzene - A Review. Conulttee on Toxicology, National Academy of Sciences, / Washington, D.C. 3. U.6. Environmental Protection Agency. 1977. Benzene Health Effects Assessment. External Review Draft, Office of Research and Development, Washington, D.C. 4. Jandl, J. H. 1977. A Proposal for a Program for Medical Surveillance to Detect Early and Reversible Changes Caused by Occupational Exposure to Benzene. Prepared for the Organization Resources Counselors, Inc., Washington, D.C. 5. Mazumdar, S.; Redmond, C.; Solleclto, W.; and Suesman, N. 1975. An epidemiological study of exposure to coal tar pitch volatiles among coke oven workers. J Air Pollut Control Assoc 25: 382-89. 6. Frederlk, W.S. 1974. Are the present limits of normality In hsmatology acceptable for multlphaslc health screening? 3 Occup Med 16: 313-21. 7. Lewis, A. E. 1970. Principles of Hsmatology, East Lansing, MI: Michigan State University Press. 8. Greenburg, L. { Mayers, M.R.J CoIdwater, L. J.; and Smith, A.R. 1939. Benzene (benzol) poisoning in the rotogravure printing Industry In New York City. J Ind Hyg Toxicol 21: 395-420. DO 068056 CONFIDENT I Al YZ0019797 9. Aksoy. M.; Dincol. K.; Akgun, T.j Erdem, S.; and Dincol, C, 1971. ^'Haa^atolo^teOi Maces of chronic benzene poisoning in 217 workers. Br J Jnd Med 28: 296-302. 10. Goldvster, L.J. 1941. Disturbances in the blood following exposure to benzol. J Lab Clin Ned 26: 957-73. 11. Erfi L.A. and Rhoads* C.P. 1939. The hematological effects f benzene (benzol) poisoning. J Ind Hyg Toxicol 20: 421-35. 12. Vigliani, E/C.* and Fornl* A, 1976. Benzene and leukemia. Res U: 122-27. Environ 13. Townsend* J.C.; Ott, M.G.; and Flshbsck, W.A. 1978. Health exam findings among individuals occupationally exposed to benzene. J Occup Med 20: 543-48. 00 068057 CONFTOFNTTAl YZ0019798  --* V 4 , za -CHEMICAL MANUFACTURERS ASSOCIATION W February 24, 1981 To: PTom: Benzene Program Panel Toxicology Research Task Qroup Carol R, Stack, Ph.D. Re: Benzene Press Release on Reproduction Studies id. .received;* ":i FE82* ij? MX DANIEL ; A- At the February 24 Program Panel meeting, the previously circulated draft press release was judged to be too wordy and technical. A new, abbreviated version has been drafted and is enclosed. 'Xt ft t. Formerly Manufacturing Chemitta Aiaoclation--Serving the Chemical Induatry Since 1078. tfOt U Street. NW Weahlngltm. DC BOOST Telephone 802/M7-1100 > Telex M017 (CMA WSH) DO 068059 CONFIDENTIAL YZ0015165 T --- DRAFT PRESS RELEASE Benzene gear of Reproductive Effects in Recent Ttests Recent research showed no effect of benzene on reproductive performance of laboratory animals, as reported by the Chemical Manufacturers Association and the American petroleum Institute. The studies were conducted by an independent laboratory. Bio/dynamics/'Inc., of East Millstone, N.J., covering inhalation levels up to 30 times the present work place standard. * Mature male and female rats were exposed to benzene at 1 to 300 ppm for 6 hours per day, five days a week during a ten week period before mating with untreated animals. Female rats continued to be exposed during the mating and gestation periods and from days 5 - 21 of lactation. No statistically significant adverse effects on reproduction or on the offspring were observed in any of the tests. At the highest dose level, two out of twenty male rats were observed to undergo some testicular changes, but this did not appear to affect reproductive performance. The reports were submitted to the Consumer Products Safety Commission, the Environmental Protection Agency, the Food and Drug Administration, the National Cancer Institute, the National Institute for Occupational Safety and Health, the Occupational Safety and Health Administration, and the National Institute of Environmental Health Science. > j! * -J v ,3 1 .* DO 068060 CONFTDENTTA YZ0015166