Document EmD026ayZR0Y85xNyN8XxBVZn

APPENDIX H Regulatory Action on PCBs Table o f Contents I . E xistin g Regulatory Authority 17 li A . Federal In secticid e * Fungicide, and Rodenticide Act B. Federal Water P ollu tio n Control Act C. The Refuse Act of 1099 (33 U .S .C . 1*07) D. The Clean A ir A ct (1*2.U .S .C . 1857 e t seq) E . The Egg, Meat, and Poultry Acts F . The Occupational, e t c . . . G. A ct to Regulate Transportation of Explosives and .Other Dangerous A r tic le s (10 U .S .C . 831-835) I I . Standards, Tolerances, or Guidelines Established m . Application of Regulatory Authorities IV . Future A ctions and Needs 177 179 l5o Tables 1. FDA Proposed Temporary Tolerances fo r PCB Residues 179 173 ADM CCC213 21. Nimmo, D. R ., P. D. W ilson, R. R. Blackman, and A. J . Wilson, J r . 1971. Polychlorinated biphenyl absorbed from sediments by fid d ler crabs and pink shrimp. Nature 231*50-52. 22. K e il, Ju lia n E .`, Lamar E. P r ie s te r , and Samuel H. San difer. 1971. Polychlorinated biphenyl (Aroclor 12L2): e ffe c t s of uptake on growth, nucleic a c id s , and chlorophyll o f a marine diatom. B u lletin of Environmental Contamination and Toxicology 6(2)8156-159. 23. Mosser, Jerry L . , Nicholas S. F isher, Tzu-Chiu Teng, and Charles F. Wurster. 1972. Polychlorinated biphenyls: t o x ic it y to certain phytoplankters. Science 175(1x018) 191-192. 2L. W ildish, D. J . , and V. Z itk o . 1971* Uptake of polychlorinated biphenyls from sea water by Gammarus oceanicus. Marine Biology 9(3) 213-218. 25* Yap, H. H ., D. Desaiah, L . K. Cutkomp, and R. B. Koch. 1971. The s e n s itiv ity of fis h ATPases to polychlorinated biphenyls. Nature (In press). 26. Koeman, J . H ., M. C. ten Noever de Brauw, and R. H. de Vos. 1969*. Chlorinated biphenyls in f i s h , mussels and birds from the River Rhine and the Netherlands co asta l area. Nature 221: 1126- 1128. 27. L in cer, Je ffr e y L . , and David B. P eakall. 1970. Metabolic e ffe c t s of polychlorinated biphenyls in the American k e s tr e l. Nature 228:783-78lx. 28. Friend, M ilton, and Daniel 0. Trainer. 1970. Polychlorinated biphenyl: in teractio n with duck h e p a titis v iru s. Science 170:131h-13l6. 29- U lf strand, S . , and A. Sodergren. 1971. E ffe c t of PCB on nocturnal a c tiv ity in caged robins, Erithacus rubecula L . Nature 231:1x67-1x68. 30. Dahlgren, Robert B ., Yvonne A. Greichus, and Raymond L . Linder. 1971. Storage and excretion of polychlorinated biphenyls in the pheasant. Journal of W ild life Management 35Ux) :823-828. 31. F r ie s , G. F . , G . S . Marrow, J r . , and C. H. Gordon. 1971. S im ila rity in behavior of DDE and polychlorinated biphenyl (Aroclor 125L) residues in an environmentally contaminated herd of dairy cows. U. S . Department o f A gricu ltu re, A g ricu ltu ra l Research Service Paper 13C.Presented at the Annual Meeting of the American Dairy Science A ssociation , E a st Lansing, Michigan, June 1971. 171 0C0211 I *s FOOTNOTES 1 . Heath, R. G .f J . W. Spann, J . F. K re itzer, and C. Vance. 1970. E ffe c t s of polychlorinated biphenyls on b ird s. Presented at and to be published in proceedings o f 15th International O rn ith olo gical Congress. The Hague, 1970. 2 . Dustman, E . H ., L . F . S t ic k e l, L . J . Blus, W. L . R eich el, and S. N. Wiemeyer. 1971. The occurrence and sig n ifica n ce o f polychlorinated biphenyls in the environment. Transactions of the 36th North American W ild life and N atural Resources Conference: 118-131. 3. P r e s tt, Ia n , D. J . J e f f e r i e s , and N. W. Moore. 1970. Polychlorinated biphenyls in w ild bird s in B rita in and th eir avian t o x ic it y . Environmental Pollution 1 :3- 26. 1. McCune, E . L . , J . E. Savage, and B. L . O 'D e ll. 1962. Hydropericardium and a s c ite s in chicks fed a chlorinated hydrocarbon. Poultry Science hl:295-H99. 5. McLaughlin, Joseph, J r . , Jean-Pierre M arliac, M. Jacqueline V e rre tt, Mary K. M utchler, and 0. Garth Fitzhugh. 1963. The in je c tio n of chemicals into the yolk sac of f e r t i l e eggs prior to incubation as a to x ic ity t e s t . Toxicology and Applied Pharmacology 5*760-771. 6 . Rehfeld, Betty M ., R. L . Bradley, J r . , and M. L . Sunde. 1971. T oxicity studies on polychlorinated biphenyls in the ch ick . Poultry Science 50(h)*1090-1096. 7. Platonow, N. S . , and H. S . Funnell. 1971. A nti-androgenic-like e ffe c t of polychlorinated biphenyls in cockerels. Veterinary Record 88(h):109-110. 6. Vos, J . G ., and J . H. Koeman. 1970. Comparative to x ico lo g ic study with polychlorinated biphenyls In chickens with special reference to porphyria, edema formation, liv e r n ecrosis, and tissu e residues. Toxicology and Applied Pharmacology 17:656-668. 9. Vos, J . G ., J . H. KoemaiJj H. L . van der Maas, M. C. ten Noever de Brauw, and R. H. de Vos. 1970. Id e n tific a tio n and ta x ic o lo g ic a l evaluation of chlorinated dibenzofuran and chlorinated naphthalene in two commercial polychlorinated biphenyls. Food and Cosnetic Toxicology 8:625-633. \ 169 0 ADH O0C209 V r v v J. Shrimp are very .sen sitive to PCBs ar.d most w ill die as a resu lt of 20-day exposure to a concentration o f 5 parts per b i l l i o n . PCBs also in h ib it" s h e ll growth o f o y ste rs. Crabs are less s e n s itiv e ; a l l accumulate residues to maiy times the concentrations in the w ater, and a t e s t with crabs showed that they lo s t the residues very slow ly. Growth o f certain species o f marine diatoms wad experimentally inhibited by PCBs, but algae were not a ffe c te d . The small marine crustacean, Gammarus, is se n sitiv e to PCBs in concentra tions o f thousandths to tenths o f a part per b illio n . Exposure to 5 parts per b il l io n o f Aroclor 12$h caused m ortality o f two species o f fis h in lli-hS days. Onset o f death was delayed and was accompanied by fungus-like lesio n s. Rainbow trout were qu ickly k ille d by polychlorinated terphenyis at 10 parts per b il l io n under normal oxygen conditions and a t 2 parts per b illio n with reduced oxygen. Metabolic changes o f PCBs have been suggested by environmental observa tions o f d iffe re n t isomeric patterns in animals o f d iffe re n t trophic le v e ls . Q uantitative differen ces also are pronounced, with m agnifications o f hundreds to thousands o f tim es. Laboratory studies have shown no metabolic changes o f PCBs by crabs and shrimps, minimal changes by f i s h , and pronounced changes by b ird s. PCBs induce microsomal enzyme a c t iv it y in b ir d s . Exposure to PCBs in creased the s u s c e p t ib ilit y o f mallard ducklings to duck h e p a titis v ir u s . O ffspring o f pheasants whose parents received high dosages o f PCBs made poor choices in v is u a l c l i f f t e s t s . Egg production and hatching a fte r pipping also were a ffe c te d . M igratory restlessn ess was increased in English robins ex posed to PCBs. Long-term studies o f the reproductive e ffe c ts o f Aroclor 12?h on mallards and bobwhite qu ail and o f Aroclor 12$h plus DDE on qu ail showed no s ig n ific a n t differen ces from c o n tr o ls. In studies o f chickens, however, egg production and h a tc h a b ility were impaired by high doses o f Aroclor 125h and by low doses o f Aroclor 12h2. S t a t i s t i c a l evaluations o f the role that d iffe r e n t chemicals may play in thinning eggsh ells o f brown pelican s showed that DDE residues correlate better with s h e ll thinning than do residues o f d ield rin or PCBs, confirming observa tions with cormorants and white p e lica n s . -IV . CONCLUSIONS PCBs are man-made b io lo g ic a lly a ctive substances th at are dispersed throughout the environment and stored in the tissu es o f animals. Ihey are le t h a lly to x ic to fis h ar.d aquatic invertebrates in concentrations measured li7 ACM CCC207 Mallard ducklings demonstrated the p o s s ib ilit y o f in te ractin g e ffe c ts between PCBs and disease organisms (Friend and Trainer, 28). T h irty -fiv e to 1*1* percent of. the 10-d a y-o ld ducklings exposed for 10 days to 'a dietary dosage o f 25, 501 or 100 parts per m illio n o f Aroclor 125k died upon sub sequent exposure to duc.k h e p a titis viru s in contrast to only lk percent o f the birds eaqsosed only to the v iru s. Swedish robins ( Erithacus rubecula) given 5 micrograms o f Clopher. A50, for 11-13 days showed a greater migratory restlessness than controls (Ulfstrar.d and SUdergren, 29). Pheasant hens absorbed 9k percent o f the Aroclor.125k given as a sin gle capsule dose, a very e f f i c i e n t entry o f th is chemical in to the system (Dahlgrer., e t a l #J 30). Residues in muscle declined 82 percent in 28 days a fte r dosage. Residue were excreted in both eggs and fe c e s . Residues in the milk o f c a t tle inadvertently e ^ o sed to PCBs declined at the rate o f 1.3 percent per day when uncontaminated feed was restored (F r ie s, et a l . , 31), The rate o f lo s s o f IDE residues was id e n tic a l. PCBs in milk fa t decreased from 12.6 parts per m illio n to $.8 parts per m illio n in about 3 weeks and to 2.1 parts per m illio n in about it months. A cow given 10 mg/kg o f Aroclor 1251* in a sin gle dose released an average o f 3.9 p arts per m illio n into the whole milk during the next 1* days' m ilkin g. A dosage o f 100 mg/kg produced 36 parts per m illio n in the milk o f another cow (Platonov, e t a l . , 32). The gas chromatographic pattern o f the Aroclors in the milk was very sim ilar to th at o f the fed compound. B. REPRODUCTION Pheasants given a capsule dose o f SO mg o f Aroclor 125k weekly for 17 weeks produced fewer eggs than co n tro ls, and a higher percentage o f chicks pipped the s h e ll but did not hatch (Dahlgren and Linder, 33) , Chicks that hatched weighed le s s and survived more poorly than co n tro ls. Eggshell th ick ness was not a ffe c te d . In behavioral te s ts o f the o ffsp rin g on a visu a l c l i f f , more o f the chicks from the dosed parents made the undesirable choice o f jumping to the deep s id e , or made no choice, in the 5-minute t e s t period . None o f these e ffe c t s occurred among the groups whose female parents were dosed with 12.5 mg. Mallards fed a d ie tary dosage o f 25 parts per m illio n o f PCBs from about 11 weeks before th eir f i r s t breeding season and through th eir second year la id eggs with s h e lls o f normal thickness (Heath, e t a l , , 1 ) . The number o f eggs la id , h a tc h a b ility , and su rviv al o f young did not d iffe r s ig n ific a n t ly from the untreated co n tro ls. In another t e s t , mallard ducks fed 10 or 500 parts per m illio n o f Aroclor 125k in the d ie t for about 5 weeks la id eggs with normally thick s h e l l s . Bobwhite q u ail fed d iets containing 50 parts per m illio n o f PCBs, or 30 parts per m illio n o f DDE, or a combination o f 25 p arts per m illio n o f PCBs plus 15 parts per m illio n o f DDE for about 11 weeks before their f i r s t breeding season reproduced as w ell as co n tro ls. Ring doves ( Strep top elia r is p r ia ) fed 10 parts per m illio n o f Aroclor 125k for 6 months la id eggs no lig h te r than those la id by control b ird s. (Peakall, 3k). Fourteen birds fed 10 parts per m illio n o f PCBs before and after dosage and nine birds in jected in tra p e rito n eally with 160 mg/kg 1-U days before egg lay in g confirmed the lack o f e ffe c t o f PCBs on s h e ll w eight. 165 ACM 0 CC2 05 fa ste r than those with more ch lo rin e s, so th at the la tte r were subject to greater increase in the food chain (Jensen, et a l . , 19). In two simple food ch ain s, fis h to- eagles (H aliaeetus a l b i c i l i a ) and fis h and mussels (M ytilus e d u lis ) to se als (Phoca v it u lin a and Pusa h isn id a), concentrations increased hundreds to thousands o f times, from prey to "predator (Jensen, e t a l . , 19). F ish contained hundredths to tenths o f parts per m illio n ; fresh mussels contained hundredths o f parts per m illio n ; se al blubber contained 5- 21 parts per m illio n ; and the muscle o f the w h ite -ta ile d eagle contained 1502k0 parts per m illio n . In Great B r ita in , birds that feed on birds or mammals contained the highest concentrations o f PCBs, those th a t have a mixed d ie t contained the next h igh est, and those th at feed on in se cts had the lowest (P r e s tt, e t a l . , 3) . The fish eating herons from the southeast o f England contained higher residues o f PCBs than birds o f ary other area. Mary species o f C a lifo rn ia birds contained hundredths to tenths o f parts per m illio n o f PCBs; peregrines (Falco peregrinus) contained greater amounts, one as high as 98 parts per m illio n in muscle (Risebrough, e t a l , , 20) , while fis h in the same area contained only thousandths o f parts per m illio n . Residues o f PCBs in the in d u s tr ia lly polluted Escambia Bay increased in the expected order. Water contained a maximum o f 275 parts per b i l l i o n , and sediment a maximum o f k86 parts per m illio n . Oysters (Crassostrea v ir g in ic a ) contained 2-3 parts per m illio n , shrimp (Penaeus duorarum) 1 , 5- 2, ? parts per m illio n , blue crabs ( C a llin e cte s sapjdus) 1-7 parts per m illio n , and p in fls h 6- 12 parts per m illio n (Duke, e t a l . , 15) . Subsequent samplings from three statio n s in the Bay showed l i t t l e change in concentrations o f PCBs in sediments even a fte r 9 months (Nimmo, e t a l . , 21), Experiments were then undertaken th at showed th at shrimps (Penaeus duorarum) and fid d le r crabs (Uca minax) could accumulate Aroclor 125k from the sediments. Relationships between concentration o f PCBs in sediment and concentration in crabs and-shrimps were v a ria b le . The maximum accumulation was from sandy s i l t containing 6l parts per m illio n (dry weight) o f Aroclor 125k; fid d ler crabs accumulated 80 parts per m illio n (wet weight) in their bodies; shrimp accumula ted 2k0 parts per m illio n (wet weight) in the hepatopancreas. Some PCBs were present in the water and a portion o f the accumulation could have been from that source. The r a tio o f in dividu al PCB isomers maintained in te g r ity in the sediments and tissu e s o f te s t animals throughout the in v e stig a tio n , in d ica tin g no pronounced m etabolic changes o f the PCBs Spot (Leiostomus xanthurus)exposed to 1 part per b il l io n o f Aroclor 125k for 56 days attain ed maximum concentrations in lk -28 days, although absolute amounts continued to increase as the fis h grew (Hansen, et a l , . , 17). Maximum concentration in whole spot was 37,000 times that in the t e s t water. These r e s u lts were very sim ilar to those for DDT reported e a r lie r from the same lab o ratory. The PCBs were lo s t slowly from the tissu es o f spot a fte r they were placed in clean flow ing water. A fter 8k days o f flu sh in g , the concentration had dropped 73 percent and the absolute amount had dropped 6l percent. Isomers o f Aroclor 125k, with the exception o f one peak, maintained th eir in te g r ity in spot. 163 ACM 0C0203 . 1. Residues in Birds K ille d by PCBs. Chickens k ille d by PCB dosage in the studies o f (Vos and Koeman, 8) generally contained from 120 to L20 parts per m illio n in the b ra in s, but the o vera ll range was from 10 to 700 parts per m illio n . Residues in liv e r s were 120 to 2,900 parts per m illio n . 1 Coturnix quail poisoned by PCBs (Phenoclor BP6). contained residues o f 3^2-1710 (av. 1158) parts per m illio n in the brain and 1079-6350 (av. 323C) parts per m illio n in the liv e r (Koeman* 1 1 ).. Bangales finches k ille d by PCBs had residues o f 70 to 697 parts per m illio n in the liv e r s ; those sa c r ific e d at the end o f the experiment contained 3 to 631 parts per m illio n (P r e stt,e t a l . , 8 ) . Residues in brains were somewhat lower; the proportional amount in the brain in comparison with the amount in the liv e r averaged higher in the birds th at died than in those that were s a c r ific e d . A bald eagle found s ic k in the f i e l d contained high residues o f both DDE and PCBs in i t s brain , suggesting th at PCBs may have contributed to i t s death. Residues o f DDE in the brain were 385 parts per m illio n , which is with in the le th a l range for DDE (S tic k e l et a l . , 12). However, the brain also con tained 230 parts per m illio n o f PCBs, 6 parts per m illio n o f DDD, 2.2 parts per m illio n o f d ie ld r in , and 0.1 parts per m illio n o f heptachlor epoxide. B. INSECTS The t o x ic it y o f PCBs to in sects also is related to the chlorine content, but in the revers order to the re s u lt with b ir d s. PCBs with lower amounts o f chlorine were more to x ic to f l i e s than PCBs with higher chlorine con ten t, and the t o x ic it y o f mixtures with more than 18 percent chlorine was very low (Lich ten stein e t a l ; , * l l ) . T o xicity o f d ie ld rin and DDT was enhanced beyond an additive e f fe c t by the addition o f the lower chlorinated PCBs. Topical ap plicatio n s o f Aroclor 1251 to a grasshopper ( Clor thippus brunneus) produced delayed m o rtality that occurred at the time o f molt (M oriarty, H ) . C . FISH AND AQUATIC INVERTEBRATES Shrimp (Panaeus duorarum) are se n sitiv e to low concentrations o f PCBs (Duke,et a l . , 1 5 ) . Al l in dividu als died as a re su lt o f a 18-hour exposure to flowing seawater containing 100 parts per b i l l i o n o f Aroclor 1251; 80 percent died in 21 hours. These shrimp accumulated 3*9 parts per m illio n in their t i s sues. Shrimp exposed to 10 parts per b illio n did not d ie , but accumulated 1.3 parts per m illio n o f PCBs in th eir tis s u e s . Seventy-two percent o f the ju ven ile shrimp died from a 20-day exposure to 5 parts per b i l l i o n o f Aroclor 1251 and the tissues accumulated 16 parts per m illio n . Crabs (C a llin e c te s sapidus) were le ss s e n s itiv e , but accumulated an average o f 23 parts per m illio n in a L-week exposure a t 5 parts per b i llio n and s t i l l contained 22 parts per m illio n a fte r a week in clean water and 11 parts per m illio n a fte r 1 weeks in clean water. 3 The small cru stacean .(Gamnarus oceanicus) had a le th a l threshold in 30-day te sts between 0.001 and 0.01 parts \per b illio n in c o llo id a l so lu tion and between r v ^J 161 ADM C00201 APPENDIX G B io lo g ica l Data On PCBs In Animals Other Thar. Man Polychlorinated biphenyls have become ubiquitous in the world ecosystem in q u an tities sim ilar to those o f DDE. Their presence has caused concern and stimulated research to evaluate their role in the biosphere. The s ig n ifica n c e o f PCBs to w ild animals depends upon both their le th a l to x ic ity and th eir su b leth al p h y sio lo g ica l e f f e c t s . These are the subjects of the present paper. Coordinate knowledge o f le v e l o f exposure, as shown by frequency and le v e ls o f occurrence o f PCBs in the enviroiment, is e s se n tia l to complete the understanding. These are summarized elsewhere in th is rep ort. I . TOXICITY Outright m ortality o f wild animals can a ffe c t populations, p a rticu la rly those o f lo n g -liv e d sp e cie s. Measurements o f d ire ct t o x ic it y are therefore important f i r s t steps in evaluation o f a chemical. Other laboratory studies also are needed for proper in te rp re ta tio n o f fi e ld observations. These in clude studies to diagnose cause o f death by behavior o f poisoned animals, tissu e changes, and concentrations o f chemical in c r i t i c a l tis s u e s . A. BIRDS The t o x ic it ie s o f d iffe r e n t PCBs to pheasants (Phasianus c o lc h ic u s ), mallards (Anas platyrhynchos) , bobwhite quail (Colinus vir ginianus) , and coturnix qu ail (Coturnix coturnix) were compared with the t o x ic it ie s o f DDT, d ie ld r in , and other in se cticid e s (Heath, e t a l . , l ) . Tests o f s ix PCB mix tu re s, containing 32 to 62 percent ch lo rin e, showed that the t o x ic it y in creased with the percentage o f ch lo rin e. In general, t o x ic it ie s were sim ilar to those o f DDE. There were some differen ces in s e n s it iv it y o f the sp ecies. Bobwhite were most s e n s itiv e , followed in turn by pheasants, m allards, and coturnix q u a il. Bobwhite were 3-k times as se n sitiv e as co tu rn ix. Sp ecial te sts with coturnix quail showed that the toxic e ffe c t s o f DDE and Aroclor 12Sh were ad ditive but not s y n e r g is tic . In other s tu d ie s , Aroclor 12$U was approximately as toxic as DDE to four species o f blackbirds: grackles (Quiscalus q u iscu la) , cowbirds (Molothrus a te r ) , sta r lin g s ( Sturnus v u lg a r is ) , and redwings (Agelains phoeniceus) (Dustman, e t a l . , 2 ) . Redwings were somewhat more susceptible to i)DE than to PCBs. Signs o f poisoning were sluggishness with s lig h t tre mors o f moderate amplitude, much as with chemicals o f the DDT group. In ter n a lly , liv e r s frequently had hemorrhagic streaks or sp o ts, and the gastro in te s tin a l tr a c t commonly contained blackish flu id , but these signs were not s u ffic ie n tly consistent for d istin ctive diagnosis. Aroclor 125h was approximately 1/13 as to x ic as DDT to Bengalese finches (Lonchura s t r i a t a ) (P r e stt, e t a l . , 3), Tremoring and other signs were simi lar to those observed among blackbirds; the finches had enlarged kidneys and sene had hydropericardium. 159 40* O C O i 62. A u lerich , R. J . , ?.. K. Ringer, H. L . Seagran and W. G. Youatt, Can. J . Zoology 19 (1971) 611. 63. W ilson, W. E. and C. Sharp, NIEH5 (1971); Studies in progress. 6ii. Spalding, J . W ., NIEHS (1971), Studies in progress. 65. Courtney, D. C. and Chernoff, N ., Personal Communication, Nov. 15 ( 1971) . 66. F u jit a , S . , H. f c u j i , K. Rato, S . Saeki and H. Tsukamoto, Fukuoka Ac*a Medica 62 (1971) 30; C . A. 1% (1971) 3797. \ 157-A ADM 000197 23- Uzawa, H ., Y. I t o , A. Notomi and S . Katsumi, Fukuoka Acta Med. 60 (1969) 119. ~ 21. Uzawa, H ., Y. I t o , A. Notomi, S . H ori, Y. Ikeura and 5 . Katsuki, Fukuoka Acta Med. 62 (1971) 66; C .A . 71 (1971) 138797. 25. Nagai, J . , M. Furukawa, Y. Yae and Y. Ideda, Fuknoka Acta Med. 60 (1969) 175; C .A . 72 (1970) 11077. -- 26. Kikuchi, M ., Y. M ikagi, M. Hashimoto and T. Kojima, Fukuoka Acta Med. 62 (1971) 89. -- 27. Nishizum i, M ., Arch. Env. H lth . 21 (1970) 620. 28. Grant, D. L . , W. E . J . P h illip s and D. C . Villeneuve, B u ll. Env. Contam. T o xico l. 6 (1971) 102. 29- Bagley, G. E . , W. L . Reichel and E . Cromartie, J . Assoc. O ff. Anal. Chem. 51 (1970) 251. 30. Koeman, J . H ., M. L . Tennoever deBrauw and R. H. DeVos, Nature 221 (1969) 1126. 31. Yoshimura, H. and M. Oshima, Fukuoka Acta Med. 62 (1971); C.A . 75 (1971) 3563. 32. S tr e e t, J . C . , F. M. Urry, D, J . W agstaff and A. D. Blau, 158th American Chemical S o ciety Meeting, New York, Sep t. 8-12 (1969). 33 Risebrough, R. W ., P . Reiche, D. B, P eak all, S . G. Herman and M. N. Kirven, Nature 220 (1968) 1098. 31 V illen eu ve, D. C . , D. C. Grant, W. E . J . P h il l ip s , M. L . Clark and D. G. Clegg, B u ll. Env. Contam. T o xicol. (1971) 120. 35 I t o , Y . , H. Uzawa and A. Notomi, Fukuoka Acta Med. 6 (1971) 18; C.A. 71 (1971) 138798. 36. Kimbrough, R. D ., Interagency Meeting on PCBs, Dept. H. E . W., Washington, D. C ., August 5 (1971). 37. Curley, *A., V. W. Burse, M. E. Grim, R. W. Jennings and R. E . Linder, Presented at l60th American Chem. Soc. Meeting, Washington, D. C . (1971). 38. Curley, A . , V . W. Burse, M. E. Grim, R. W. Jennings and R. E. Linder, Interagency Meeting on PCBs, Dept. H. E . W ., tfcshington, D. C . , August 5 (1971). 39* S e k ita , H. M. Osawa, Y . Ito and H, Tanabe, Shokuhin Eiseigaku Zasshi 11 (1970) 361; C.A. 71 (1971) 138818. 10. Albro, P . W. and L . Fishbein, NIEHS (1971), Unreported r e s u lts . x 156 CL-/- ADM 0 0 C 195