Document zdyG5krJpgb1vVQe2BVwaXM2n

i " A publication of the Freshwater Foundation "" fiitluilHg infitTmatimfrom tls HtttHb & Unrironmtm AW*nr* Volume 2, No. 7 /August 1983 Feature Article Polychlorinated Biphenyls: , 1st. How Do They Affect Human Health?. . Until 1971, polychlorinated biphenyls (PCBi) were different composition from commercial products. Most' ' used commercially In the U.S. in capadtots and trans- are similar, but not identical to Arodor 1254. formers, carbonless copying paper, paints, andhydnuik .v.., --.a-.-: ~r.-r v >' . fluid. While many countries have since restricted PCB . ; A Studies in laboratory animals/ ... . , use, die-compounds are still found in old ttamforms,14?i^^V^ To learn how PCBs,might affeq health, investigators capacitors, and other products. -. -rh'` haviTstudied PCB exposure'experimentally In animals -. PCBs'are a group of 209 stable, ht-soluble chemicals/, and to humans occupationally or accidentally exposed to Not easily broken down, they have accumulated ln fishjtii :i dte compounds. . ; ; _/ from polluted watcrwavsiin wildlife, and in human"/.v Except for feeding studies In*hilnk, which used PCB- ^ " organs', fatty. tIssue; biood" and mflk. In thi late 1960s.`^/j^-. polluted, fish, most animal studies have tested commer- `jiLI J ^*-7--*^^ "-1" t DmiIm ,1umi ili4r fk. lAvWfV r\f mmmmi t!~~. restrfedons ihc/otheir tneaiures.r polluted,fish arg.die/ltfl? /i high dcgrecof chlorination, produce rffi primary /ood sodree ot PCBi tor humaiis.iap^-^np.^rr Mixtures with much less chlorination, on the other hand, Z -Z'-TBeousethey are fat"soiubicTPCBi tend toconcan-- yield# muchlower cancer Inddence, with a tumor - tratc In fatty tissue; and to a great extent, PCB levels in incidence similar to that in unexposed rats. Most tests different organs depend on the organs* fat content. Thus, have not demonstrated any mutagenic properties for ' In humans, fatty tissues contain the highest PCB concert-.. PCS*-'. nations. In fish, the behest levels art found in body fat - * . * Other adverse effects observed in different animal . and the hepato-pancreas, not the edible portion. . > spedis vary"Whfie all mixtures andcbhgeners* tested . Arodor is the commercial name for the American '.. induce mlxed-ftinction oxldases in the liver, the type of product of PCB mixtures. .Different mixtures are further. .. enzymes'Induced varies. PCB bomen dut appear more ri identified by codes, such as 1242,1016,1254, that ..* toxic and that.are retained longer In the'body seem to.: designate die percent of chlorination of the mixture... " ' r. Induce aryl hydrocarbon hydroxyfiscTLiver 'enlargement" Because the time necessaty for different components of ' scons to accompany enzyme Indualom ln some species'. PCB mixtures to break down in the environment varies-* fed high dosesof PCBs/tavestlgators have observed liver. PCB mixtures found in soils, sediments, and biota have a ~ ~cril necrosis and fat accumulation In liver ceOs. '' - Editorial Board rwmis h. ssmmm, nrn. - DMdan r Ctne*r Itakm MUtul mumm t Hnu, NtumCinear bu cHnw*rA.Aa4MMw.ua. *">*"Um*m Chme Ouuu Mow mm Ml* BmB, UJ. MUX . CDMfwMrrumwyMMM<MnMimiuiMtaMagurCft!t ynwAHatiift . CmiIM Ur (mMammul Mmiw Cxiurt ur Onto* CornU Mbm X MMU.M.O. M.WC Mr Ptgtnmmrrmiminingr ... ion) m **ac hnioi UKAtrUVUNMietrUM* . SmlilMMigAWft ' WMiMWCUMUa OHM M M AOMMtrusr MMXtMUtaut OapMtmwtfhMMar McUgnSUMUrUtrUV ' ' Rkkutf AUHM.kLn.lArM. DDMlrtMcuMf UftSeMMiiigUgr '. CrwriwU MMiry UiAgU U `mSKiUAM OSerfniMgV--UuKIMHmHMwiMi . . IflMlPy 91 PS'SWi i " h|rt X Ntr. m.O. da wt o*r CMMnU Mmhimi Hum "vWW*MH.uO. MMwrUSoeiUMtdleM* MtUrlft MOCM et*f AMri Cmum Ctrug* M MtMUt Aimm 6. tu<ws m.d. IMSMM M UMMt SHMfhhuW iMI ' UnUuViy ll,HrH ChW MUAMaUt OMwrtlMmgM 6BRNQ03110 ONE E X H IB IT 8 TOWOLDMONOOQ2596 Rhesus monkeys exposed to technical , Even workers with exposures two orders,./ ' PCBf have developed hypoplasia, or OTcr- ' -' ^of magnitude greater than environmental yyyy... _ * grow th, of the epithelium of the gastric * .ptposures seem to show no convincing'7 ' ; mucosa, In rats; investigators hove obscrod.; chronic health effects. In a number of capadhV^. "* cell transformation, tooting that hepatic cells ,, i tor phjia, workers developed chloraicne, a transformed into pancreatic cells. This effect: *. persistenfskln disease that primarily affects^ on cel] differentiation, apparently modified by hair follicles. Whether the chloracnc resulted by Hecate D. ' Kimbrough, MJ>. U-S. Zarlronracn- tal Protection Agency, Office of Regional Opera-' (tpof, Director, - . Health Risk Capabilities . the epithelial growth factor, is tnotb pro>. from PCB exposure or from exposure to ' Bounced in rats exposed to Arpctor 125<."V.. .chlorinated diberuofurans, 9 known pausepf..\ ' Because the mixtures tested may have beetaV - chloracnc and a possible .coniamina'nt'bf the'y'yV' ' contaminated with chlorinated dlbcrizpfunyjji, _7"PCBs. U unclear. There Is reason to belkye ;' r*r r such contamination may have contributed.to 7 ' 'that chloracnc and other health effects pop'u-7, '/V-'";. the toxic effects and be panly- responsible for ; lariy associated with PCBs are reallycaused by ..yy the variation In effects seen benvecnjnixmr.es . `chlorinated dibenzofurans. ' '...........2U. and between animal species,y- ln '1968 in Japan and In 1978*7?Jin. ' H" In experimental animals, some mixtures 4. ' ' Taiwan, two poisoning outbreaks took plaice'*- 7-' . 1 affect, reproduction more than others,' but ail - - in people who accidentally ate rice oil coni ` . '-' `.-I effects have been fetotoxlcl In minks and vy.'" laminated with a mixture of PCBs and poly- y ` y-.* "* Jnvi^gatorthayie noted sponta;.. :-^;'cWorihiitJ dibenzofarans. The poisoning,'. 7 :f: -. `heous abortion*; In jiodentt'd^yTid^ seen' '.rr"ealfed YUsho disease injapap indYh-cheng ~,r.- .. resorptions. Expbsure m ltwler do'so may -'1" , diseasc ln Taiwan, led to chlobcne and dark > ' ' Chlorinated dibenzofurans - nay b* respond* ble tor the health effects attributed to PCSs. I TWO have been demonisntrraatiecdd Uii'peoplewho carty \ ^dgatiori teabtlshed chlorinated dibeneofhrafiijV*-.' as the riuie <kpc^td^2^:,':<22~v~: r/`!Qni'rcMO:n forj^'ebriduston is that U-S.*"'' 7 /workes exposed tortuchlWgfter PCBdqseS . Uianpatientj with Yltsivb^artd yb^dh^g' dV' - ' ' ease do not showthe`same JicaTcii"effect*'-! V "r - Some workers complained ofburning .eyes, c; nose, and throat. Some studics reported - 'Y.lT.V.' " . . .abrionralUvor fbnrtofljests. pne ttudy, in a ; Y capa'citor plant, noted abhomui lung fttnetton:. ; tests among the workets. However, these - : 'workers had also had other exposures that ; v . could have resulted, in abnormal lung-ftinctloh . ' ' Attempts to conclusively demonstrate yY ' ' health effects in populations that cat' flsh from - - - body burdens of PCBs from environmental polluted waterways have generally failed.' - ' - . exposure to trace amounts of PCBs. Such _ ' Occasional reports have noted behavioral ' - ~ A exposure is'much less than that received by changes and shorter pregnancies with higher: '.nar workers w ho made transformers or capacitors fish consumption or higher intake of PCBs.4'' from the 1940s through the !9?0s. ' However, because these studies couldn't rule GBRN003111 -v TOWOLDMONOOQ2597 ^ out other causes, the.significance of their and whole serum PCB levels increase with / finding is unclear..' ' ` r * ^- ^/.^eraJ owpailotul studies hare pre- age. They are usually higher in males than in ` females, which corresponds with population -^sented no condusiivc scientific evidence that survey findings that females usually have -c;! .fCBi have caused cahcer In humans.* While lower cholesterol levels than males In the `one study fourtd a positive association same age group. Finally, the prevalence of - - -.--between PCS blood levels and high blood elevated blood pressure also increases with I-Vpressure,* the association appeals spurious. age. In essence, ail the associations go in --'Thelevels;of fCBs In serum are primarily a tandem and appear to be spurious. V .. ftmetfon of the amount of fat present in Thus, despite positive laboratory animal -.eriuit. Serum PCB levels arej for instance,- data and except for chioracne, exposure to "'positively torrelaredwlth blood cholesterol - - - PCBs has led to no convincing, dinfcaily .* - " - levels.*-7 The associations disappear when PCB demonstrable, chronic health effects In * r.t JcvclsSrC expressed as a ftmetion of fat in humans. l f Sehiin.rather than as whole serum. In popula':v 'lions on Western diets, both serum fat levels `Mcffiben of the amc domical family; ecfc member <Slfen la the aumhrr or location otiubuitscmi. I^imnc /. Kim. kiimgf r >-, Imiron Hnlih trap. Kirs la*. 19't. 1. Kim. frrmft X ml, ErniroA Health Amp. }>. 99lOt. lOtf,}. Kim. MqlSati AM. lev. Pharmocot. fttJnl. 27.-S7.///, /Of?, < Jmevtmm t> at. DK. Parchoi. SO.MM. Wt-SW.Ket,), Pedlatr. IOS.-J/S.JM /9f4-& JTrrMrtat.J. Am. Med. iwe. . WJfOfJfO* l9tl, UwaMlte, tmrt- on. Hohft Pens. so/ts-iH nh. Commentary . Harnessing Natural Processes To Degrade PCBs. by MichaelA. ~ Kxzarin, Ph.D.^ ' Preferfor, Center for Envlroatnen:. trl Toxicology,-'. Michigan State University " . * V'A numerous aitiljrpa uf all, water, sediments, wildlife, and other * ~ -. environmental samples have shown, PCBs are extremely persistent coo ' pounds found in all parts of the - * environment. * - . . .. ' ' In ambient air and water, PCB levels sue quite low. Even if one - assumes a lifetime exposure to the highest measured levels all day every day,'air and water offer a low risk Of human exposure. Fish, however, appear to be a more significant source ' _ of PCBs.' Why? First, PCBs bloaccu. mulate and biomagnify in the aquatic ' i food chain. Funher, as many people become more health conscious, they ' tend to eat more fish. For people who subsist almost entirely on fish they catch themselves, high environmental PCBs In fish are tbe sediments in levels plus high consumption can lead contaminated riven, lakes, streams, ; "to'significant exposure. - " andestuariea. About one-third ofaD -^Because fish are sueb an Impor PCBs jn tf>e global environment are tant source of PCBs, government contained In fresh and saltwater agencies have taken steps to minimize sediment^' " ' this exposure. On the federal level, Most remaining environmental the Food and Drug Administration has PCBs seem to be stored in open set maximum tolerance levels for waters around die world, largely as a ' PCBs in fish sold in imwctoxe com result of ltmotphrrir transport and merce. To address intrastate consump deposition. Despite worldwide disper tion, some states publish fish ' sal, however, studies of oceanic life advisories that recommend limited or ` suggest that PCBs'are not evenly dis no consumption of fish from bodies tributed: the highest levels are in the of water significantly contaminated northern hemisphere, especially'at lat with PCBs and other chemicals of itudes that encompass the industrial concern, a number of states border* nations. ing Lake Michigan have collaborated In addition to the large quantity on a common advisory for lake Mich of PCBs in the environment, an igan fish. approximately equal amount is still In use, mainly in dielectric fluids in PCB reservoirs sealed electrical equipment. The most Limiting exposure by regulation or recommendation does not address Important step for limiting future exposure entails exercising great care the fundamental reservoirs of expo in disposing of all FCB-containing sure--where PCBs are stored in the materials stdl in service, fat most. environment. Available data dearly cases, users of electrical equipment indicate that the main sources of are taking care; continued vigilance GBRN0D3112 THREE I TOWOLDMONOOQ2598