Document BRXxJQzRGE3XGJgx1JZqE4QkJ

15*14 CHtWSTW to. sc juiv/mn. com*, v.ooo MAY 1976 ! A W'll Polychlorinated Biphenyls in the Environment Snlvslof* R. DINnrdi end Anne Merle Decmerele University ol Massachusetts. Amhorst. MA 0100? Volv<hb>rinnlcd biphenyls (ITHs) firs! used ill were soon heralded fur their dixlinclive cltf-mienl imd physical properties. Since that time, they have l*een widely used, Imili in ittvlwUy tuvii ntffividiwv Ten years r*u*. mum* group* I1<> innnilnr tin- rinirnn. nu-nl more Hourly. ITMs were idenlilit-d as widespread euiilaininimls, distributed iti air. iiiiIit. and animal >md plaid tissue*. The ITM ennlainitndinn problem is Tin .sc rill|HaiiMls were nev er hiu,)nm:l\ iliv trihuled in (hi- environment, and their wide xprend loiilimiiiiati'iii mine its n surprise lo iIk- Kiiciitin. eoiumiiiiitv 111. Synthesis and Properties mis are synthesized commercially by ennlrolli'd chlnrimtl km id' biplienyl nidi uii hvdron* chlorine, using iron fitlng* or ferric chloride, KpCI i. as a cAtalysl (21. The pn.ee** yields hydrochloric arid hihI a mixture ol ITHs, Of thr `210 iheoretiral IT11 ,-m. pounds, only )0? are probable (2. V) ITUs are eurreiilly miinnhulured in Ibis rountrv by Monsiinio. under (he crude mime Am rblof. They are also niiiniilnHiired in Inprtii, ihe UKStt, Frame. and (Sermiiny. Amrblor rnni|tuiOMl* are designated by a four.digit minilH-rinp Byslcio Tire lir.i inn (Units dexeriht* die compound and I be Iasi ln ilenole percent i liloriuulion. Fur exam ple, (lie prefix I? deludes a ehlorinaled hi phenyl, awl Amchlnr 12r>l contain* ,V("u by weight of ehlorine. Inclmled among Ibe Amehlnrs are polychlorinated lerphenyls. ITT. Hilfcrcwt AriM-Mnf* cnnlnirt from -M |i. IK",, chlorine. Anahlur* with low ehlorine eoiiienl are liipiids. with visrosilies ineiensini,' with in ernisinp ehlorine. Highly chlorinated ITMs arc while crystalline solids and hard trims pmeiil resins I />, They are chemitnllN Ineii, (hermally stable, and virtually oncomhn*ii ble. Tliev resist prolonged healing m top T ami ilei'om|Nme only at almtil b.Mt *(*. They 14 CHEMISCRV VOL 40 NO 4 am be disl jib'd id nlmi..plu'n po ..hi., n .1 |i mil npprrciahlf decomposition 1 f i '>i lil'islaul In mills, nlk.ili. .mil mii.-ivo chemicals, I'l'Ms me iii.ulnM, in n.u.i nod idh\t alcohol lad soluble in hpnt. I la 11 t,,.it ni|i poiids rnngc Iron* *7* In If. l' lino projieriii's nre similar l>> lim...... I I'l'l an oilier 1 hlonoidisl iirnrinilii i'.iii|n.mill .mil Us imnlognt-s I alike HOI |mlv hl.nio m d biphenyls have 11 low. lad limic. vapm |>n. son .Mid run i-tist Ml the vapor ph.i.. Inlili. gaseous molecules have Ism di li led nl Tm NiCnifTU, .i. () Uaot ITUs' primary iki i< in mdusirv as pln.ii < i/ers {iirg.iinc ioin|sum<ls that m. ,,.isi lit \ ilnlilv and (iiuphuess ( hi^ti p..ls m i. I.v m tirind soK III inn I, Inal llai bine oilier i|c. As plasln'i/ers lia s an- u-i d 10 s\ ni la res ms. |Minls. sMillain mill a.nurd inlilai., dllolose resins, tarnislHs. m ivc. ,i-|ili;ilk, and alkyl sImhIh s ITItv me inticiln o'. in |M|ii'ibniird, 1 mdln.md. and I In ink- in 1 nr liolili ss (op\ inp )>npcr Tin 1 m 1 ,1. .> m ili,|. I<> extend llie kill lile id oir:,iiiiM blmiia him, liciilt's l *. I'olxehlorinaled bipla n\ Is .m us, d also as na .ilnnfs in liipb |iiissim lodi.uila .on ni. nod i;iisl;cts, in diisi suppiession. ..... -111 a>piiHilint*, ioipn^nalioi* and \.i|s<* .ii|i|in. sioii pr,K i sses; as a plu.iii i/* r and > \imder in henl lriin*lir nisi diiti'lm -v.liiii. m i ooihinalioi) Midi |iolv>iiivl ihlorid*' as a llame relnrdant. and in 1 nttibrnaiion iiilh lo bin atinp nils in nimbini iv used in tmal pi., cessini; and n^rii idlnn i;'. < I Environmental Problem Allllooxb I'Clts Inn,. Imu; l,, , ,. nn.-oi/*d in a health liazard tor iiubi-lrial vviuki i. who initsi bundle Ham (Im u pn--ddi rllnt. mi (lie general |ai|Hiliitian and the 1 in.....mu id wi re not rccfiuired uiilil I'sa; Tin. a . 1 roc tor several reasmis Kirsi. I'l H. wm .... .. MOMS 036675 lilxTHloly distributed in tin- environment. Unlike DDT and other contaminants, they were used with a few exceptions in dosed, embroiled mnmd'nel tiring processes. Second, IH'Bs produce low aei/fc toxicity; most lxi<* effects result from c/mmic exposure. In in dustry, precautions were taken to protect workers from toxic levels, hut it is more dil'fictilt to protect from or keep track of sub acute, chronic exposure. Third, P('Bs are extremely difficult to de lect, and their detection in the environment is an interesting chemical problem in its own right. Solution of the problem was found in gas chromatographic studies of DDT-con- taminaled tissue in the early HIGOx. With use of more refined techniques to purify trace materials, several 1)1 )T analogues and me tabolites were found in animal tissue. In HK9, S. .Jensen reported up to 14 peaks in chromatograms of lipid material from eagle leathers. Several of the peaks did not corre spond to I )l )T analogues (/). With the cooperation of museum officials in Sweden, feathers were removed from ea gles in collections similar peaks were found in lipid material from these 27-ycar-old spec imens. Because 1)1)1' was not used until 194ft, it was dear that I he newly discovered peaks were not from 1)1)1' mctnlwdites. Two years later the unknown contaminant was identi fied hy gas chromatography and mass spec troscopy. The new rm)>ound showed several mass spectroscopy fragments, all differing hy .'M mass units. Chlorine, which occurs natu rally with a peculiar isotopic pattern of 7f>% of ddorinc-Hft and 2ft% of -37, will contribute to such a mass spectroscopic pattern. By 191115, the unknown was identified as PCB; peaks of commercial Arochlors matched those of the feather extract (/. 2). !,ntcr I.. Kishbcin (bund that PCBs ns a class could )>e separated from 1)1)1' and its analogues by another, simpler method- frac tionation on a silicic acid f'clitc column. Mi Lake ife-n suPerior Lake Ontario Lake Erie W'lU can accumulate in stream* and lakes. I.ast yrar some commercial fishing was curtailed when high I'CH levels were found in fish from the Great Italic* Major Routes of PCB Contamination --Industrial smoke from Incineration of PCBconla'mlng materials. Few facilities provide the required decomposition temperature of 950 C. PCBs also persist In the vapor state, and even If not vaporized, have a strong affin ity for particulate matter. -- Waste In rivers and other waterways from the dispose! of waste oils, waxes, and paints from Industrial or other sources. -- Landfill leaching from PCB-contalning piaslies and resins. --Insecticide runoff of PCBs which are used to extend the kill-life of aldrin, dieldrin, and chlordane, or as a synergist with lindane. -- Recycling of PCB-contalning paper. Even virgin paper can be contaminated through manufacturing processes. --Direct contamination from leakage of heattransfer fluid, hydraulic fluid, or oils --Concentration In biological materials. PCBs are lipid-soluble, and therefore are concen trated In the food chain. They are concentrat ed in sewage sludge by lipophilic substances. >0 ^ m O ^ ^ Q X MAY 1 976 CHEMISTRY 15 Thu?: separated, they can then he studied more readily. Comparison of gas chromato grams of PCBs and DDTs docs show several interference points and overlaps, raising speculation that much of the DDT found in miinuil and plant tissue throughout the 1950.S and early 1960s may have been PCB (9). The large number of PCB isomers increases this possibility. Universal Contaminant Since 1966, PCDs have been found to be a universal contaminant, with much the same distribution pattern as DDT. They have been found in human and animal fat tissue, milk, foodstuffs, plant tissue, zooplankton and phytoplankton, and even pine tree resin. Their distribution is not uniform. High con centrations have been found near incinera tion plants and water treatment facilities, in some recycled paper and cardboard, and in leachates from landfill areas. Patterns of PCH dispersal can he traced by following air and water currents and wind patterns (10, 11). However, excluding a few accidents in volving pipe breakage or industrial mishaps, PCB contamination has l>ccn unintentional. To quote Jensen, "It has entered nature through the hack door from industrial smoke and waste (/)." Persistence In the Environment Compounding the problem of the wide spread distribution of PCBs in the environ ment is the fart they are among the most sta ble organic compounds known. Unlike DDT, which has some degree of biodegradability, PCH* are not broken down by most living systems. Achromobavlcr, a bacterium used in waste treatment facilities, when growing on p-chlorohiphcnyl will dechlorinate PCBs containing one or two chlorines per molecule, hut not higher chlorinated compounds (12). PCBs are not readily degraded by physical or chemical means. Tow-chlorinated com pounds can Ik1 dcchlnrinated by ultraviolet light, but rearrangements and condensations merely produce now and unknown compo nents. PCBs' increased chemical stability over DDT is due to absence of the ethane group between the aromatic rings, the site of most DDT degradation reactions. The most effective hut impractical method known to remove PCBs from the environment appears In he combustion at temperatures exceeding DM) C at low oxygon levels (7, 2, 6). Health and Toxlclly Polychlorinated biphenyls have been re . gardod as potential health hazards almost 16 CHEMISTRY VOL 49 NO 4 since their introduction. In 1930, C. H. Pen ning described them as odorless, tasteless compounds, producing no noticeable skin ac tion but causing irritation to nasal passages when concentrated vapors are inhaled, some times producing violent headaches. By 19.17, PCBs were recognized as toxic to the liver, as are most organochlorinc compounds. Toler ance levels currently prescribed for industrial handling of PCBs approximate 1 mg per cubic meter of air. In industrial use, PCBs can produce moderate to severe local irrita tion, and severe effects if ingested or inhaled. Effects of chronic exposure range from chloracne, a skin eruption, to hepatic coma and death (13, 14). The effects of PCB exposure are magnified if there is simultaneous expo sure to carbon tetrachloride, a severe hepatotoxicant (13). Toxic effects of PCBs in the animal king dom have been well documented. Along with DDT, they have been implicated in eggshell thinning in birds. Both induce degradation of estradiol to estrogen, inhibiting calcium me tabolism. In chicks, 50 ppm Arochlor 1248 in the diet decreased body weight and de pressed secondary sex characteristics, hovels of 100 ppm depressed hemoglobin and blond cell volume significantly (75.76'). In pregnant rabbits, PCBs were transferred transplacenlaily to the fetus, and concentrations in the fetal liver exceeded those in the doe's liver. Skin changes similar to chlorame have been noticed in rats, rabbits, and guinea pigs. More importantly, liver damage has been im plicated, though mechanisms of toxicity are uncertain (17). I). R. Bickers and associates found that for fish and birds, Arochlor 1254 increased levels of hepatic mixed-function oxidases, enzymes that hydrolyze a large number of drugs and steroids (18). Environmental Impact on Health. Kffects of PCB ingestion in humans came to light in March 1968 on the island of Kyushu, Japan. A new disease, kanemi yusho, which affected 1080 reported victims and possibly 15 000 others was traced to contamination of Kanemi rice oil, a common foodstuff, with a PCB that had leaked from lubricating oil in processing machinery. Four variations of this disease were identi fied: latent, visceral, manifest, and tardive (74). In the latent type, there arc no symp toms, but PCBs can be detected in tissue. 'They can be transferred transplacentally, or to infants through their mother's milk. Such infants show dark pigmentation of the nails and mucous membranes of the eyes and mouth. No dermatological signs are present in vis ceral kanemi yusho. Instead, victims feel fa- MONS 036677 < PCBft--Current Statue _ Monsanto, currently the sole United States PCB manufacturer, plans to phase out produc tion. Tho principal stumbling block has been finding an adequate substitute lor PCBs in the leelrlcal power industry. Tholr unique combi nation of electrical insulation and good heat conductivity makes them an ideal material for use in transformers. Monsanto, as well as Dow and Exxon Chemical Companies, are working to develop subslituies. Though none ol Ihelr compounds to dale combines all the unusual physical properties of PCBs, they do appear to be less toxic end. more importantly, more biodegradablo. Interestingly, a recent report suggests that PCBs might be biodegradable by a new bacte rial strain (Chemical Week, Feb. 25. 1976, pago 47). Scientists al the Canada Centre for Inland Waters first disperse PCBs with ultra sound and then add sewage bacteria which feod on Ihe chemical. One bacterial strain in particular appears to delight on a diet of PCBs, and thus might prove a means to curb ing the chemicals' persistence in the environ ment. JLF tiguc, nausea, vomiting, mild jaundice, and colic-like abdominal pains. In some patients, symptoms included diarrhea, productive rough, chronic bronchitis, asthmatic attack, and pneumonia PCBs can he recovered from sputum, blood, mul tissue. In many cuscr, in creased serum triglyceride levels of pre-fi-lipoproteins have been reported. Only victims showing manifest symptoms were officially diagnosed as cases of htmvmi yuslio. Dermatological signs of organochlorine )Musoning were present, including ebloracne, a follicular eruption resulting in dark hrown pigmentation of skin, nails, and mucous membranes, and a discharge from the eyes. Other effects in these victims included loss of hair, loss of libido, fatigue, numbness of extremities, headache, aUiomiiml pain, nan sen, and diy./inesH. Dong-range effects include higher neural disturbances such as memory hiss, local impairment of circulation, dislitrImiikvk in lipid digestion and metabolism, hone and joint deformities, morphological changes in teeth of adults, and poor teeth de velopment in children. In (he tardive variation, symptoms of DOB poisoning were delayed in their ap|>carancc for up to three years after the Kanemi rice oil incident. When one realiy.es that symptoms can take so long to appear, it is rlcnr that other similar diseases of uncertain origin may Ih* related to long-term, low-level ex|>osure to polychlorinated biphenyls. Suggested Reading (1) Jewm. S., "The POM Stnrv", Anikin. 1 (41 |-j:( (19721. ` (2) Fishbrin, I,.. "Chroniniojjraphir and Hioloxnal A* perl* *>f PolveMorinnti d HiplunvU", J ('hniiiinlnKr BS, mu72t. ' CM Holden, A. V , "Souree of PoJvchlnrutnlrd Hiphcnvl Contamination in the Murine Knvinumteol" Noturr 228,1220 115)70). ' (4) Arorhior Plnl i i/,ers, Twh. Hull <l/l`t.ioi< Minivan In Co.. 1908. i.r>) Penkell, I>. lb. I.ineer. -I I.. 'T.>lv<l.l<.rmni<<l Mi ()Ih-ovIk: Anolher Long-Life Widespread ChemieHt m (he environment", HuiStuiuc, 211117), !)f> (l<)70|, (0) KsHhkihi, I... Hiwen. K., "On the Thermal Devtrnr lion of Polychlorinated Biphenyls. Some Kquilihrinm Considerations". ('hem St-r., I, (II (10711. (7) Lichtenstein, C. iV, Srhul-/. K It., Fidiremann. T. W.. Liang, T,, "Mioloyiinl Inleraelion Between I'lastu i/- eri and Insecticides", <7 /.' on />ii(imn( , 62.7U 1t'.X/.M. (8) Tsao, C-H., Sullivan, W, N.. Hornsleiii, I , "A Com piirisoti of KvapnrHtion Males nod Toxicity In House Kliex of Lindane and Lindane Chlorinated Polyplirnvl Deposits", ibid . 4(5, 882 <)!);>;)). (9) Holmes, 1) C . Simms. 1. H . Ttiltnn,O'tJ. "fhlo rinAted HvdrornrlmnK in British Wildlife", Nature, 216, 227 UHP.7). (10) Sudrrgrrn, A.. "Chlorinated ItydrocarlHm Residues in Atrlairtie Fallout", ibid., 2Bf>, ,'U).r> (19721. till HiHchrough, M. W,, Huggell, |( J., Friflin. .1 J, fioldla-rx. K. 1).. "Pesticides; Trauviitlamir Mineimidv in Ihe Northeast Trade*", .Vi,,,|.1, I2:t:t (PKIH). (12) Ahetnd, M.. Fneht, I). I)., "Oxidation of Polvrldori nnted Biphenyl by Aehromahwter PCB", Boll f.nurou ('niuani. Toxicol, 10 (2), 70 (197,0. < LI) Max, N. I.. "Dangerous I'rojHrtics i*f Industrial Mn tcriaU". ltd pd., Keinhnld Honk Corp., New York, N.Y., 1908. (14) I'mcda, G , "PCM Poittcming in Japan", Ambin, I (4), 1.12(1972). (10) Uiscbmugh. It., iteiehe, l'., Penltall, t> It., Merman, S. Kirvcm, M. N., "Polychlorinated Hiphco\|s in the (lolial ICeoK.valrm", Nature, 229, ION!) (19091. (Ml) Helifietd, H, M., Bradlov. H. I... Jr.. Sunde. M I.. "Tnxieilv Slndies on I'olveldorinaled Bipheuvls in (he Chick", Toult. Sci.. SI, 488 (19721. (17) Kxccutivp Offiee of the President, Oilier of Science and Veehmdogy, "Kcnlngirnl KMeels of Pesticides on Non-Target Sirecies". Su|w>rinlnndenl of I lornmnils, ILS. C.ovetmnrnl Printinu OUiee. VVnKlunxtun. M.C.. 1972. (IH) HiekerH, H., Hnrlier, C., Kappas. J',. "I'olyelilorinat ed Miplmnyls: Comparative K.ffeets of Hi^h and Low Chlorine Containm# Ar>K'hlors on Hi pntie Mixed Fuim (m Oxidaw", ('him. I'athul. I'iuinniuit)., .1 01), o0`> (19721. SALVAl'OHE H. PINAIltH is dinirmnn nf the Etwtronmrntal Health /Vogrom Aren at the Uni versity of Massachusetts. His research interests include sampling and analysis of chemicals in the environment, particularly inorganic mercury, hut also lead in New England maple syrup and HUHs from landfills. ANN MAltlE DESMAliAlS studied biochemis try at the University of Maine at Orono. She is a certified clinical chemist, and is concerned u<i(!i elevated blood lead in children. Her research in terests include toxicological effects of e/icmicu/s in the environment. M0NS 0 3 6 6 1 8 MAY 1 976 CHEMISTRY 17