Document reGoyk00EwDBDwoGYrBe65vGE

(I / Polychlorinated Biphenyls / i& J^/Jo/ ? Another Long-Life Widespread Chemical in the Environment .David B. Pcakall and Jeffrey L. Linccr The recent finding that pelagic birds rfying on the coasts of Great Britian had polychlorinated biphenyls (PCBs) in their livers in concentrations of several hun dred parts per million (Bourne and Mead, S969J shows that these compounds are present in the ecosystem in large amounts. Thus, it seems worthwhile to summarize and evaluate our current knowledge of these compounds. ' . Structural and Physical Properties The picture is complicated by the fact that we are not dealing with a single com pound. The basic structure of PCBs is shown in Figure 1. Any of the positions marked with an x can be substituted by chlorine. Widmurk (196S) has calculated that of the 210 possible combinations 102 are probable. His criteria for these lim itations arc those compounds containing five to eight chlorine atoms per molecule and the number of chlorine atoms per ring differing by not more than one. The commercially available Aroclors (Monsanto Company Trademark) are des ignated by numbers (Monsanto Technical Bulletins). The first two digits represent the molecular type: 12 - chlorinated bi phenyls; 25 and 44 - blends of chlorinated biphenyls and chlorinated terphenyis (759b biphenyl and 60% biphenyl, re spectively); 54 - chlorinated terphenyis. The last two digits give the weight per cent of chlorine. Thus, Aroclor 1242 is a chlorinated biphenyl containing 42T chlo rine. The biphenyls commercially avail able from Monsanto range from 2ITc to 6STo chlorine. Mass speetrograp'nic studies of Aroclor 1260 (Koeman ct ah, 1969a) show the presence of 11 isomers: five con taining six chlorine atoms, five containing seven chlorine atoms, and one containing eight. Bagiev et al. (1970), studying Aro clor 1254, found IS compounds: one con taining three chlorine atoms, four contain^' ing four chlorines, four containing five chlorines, five containing six chlorines, and four containing seven chlorines. Thus, The u!hors arc current') j! the Langmuir Laboratory. Cornell Uni*mity. Ithaca, N,Y. . the number of compounds present is, for tunately, much smaller than is theoretical ly possible. PCBs are chemically inert, are not hy drolyzed -by water, and resist alkalies, acids, and corrosive chemicals. They have low volatility, their boiling points ranging from 27S C for Aroclor 1221 to 415 C for Aroclor 1268 (Penning, 1930). AH are stable to prolonged heating at 150 C, and the lower Aroclors can be distilled at atmospheric pressure w-ithout appreciable decomposition. PCBs are described as in soluble in water and very soluble in hydro carbon solvents, although no exact figures appear to be available. Nothing is known about the biological decomposition of PCBs, but it is likely that they are more stable than DDT and its metabolites since they lack the ethane component between the aromatic rings, which is the site of action of most of the transformations of DDT. Thus, PCBs have the necessary physical and chemical characteristics for persistence and accumulation up the food chain. Use of PCBs Polychlorinated biphenyls were first de scribed in the iiterature in 18Si (Schmidt and Shultz, 1881), and the successful com mercial production was achieved by the Swann Company in 1930. In that year the physical characteristics and commerica! possibilities of these materials w-as de scribed by Penning (1930). PCBs are now manufactured by Monsanto in the United States (Trade name Aroclor), Prodelee .in France (Phenochlor). and Bayer in Ger many (Colphen). Other manufacturers are located in Japan and the Soviet Union. No figures of the amount of these mate rials produced annually are available, but to judge from the uses listed in Table I they may be very large. The uses listed in the table are only suggested applications taken from Technical Bulletin 306 of the Monsanto Chemical Company, and again there is no information on the extent to which these recommendations arc acted upon by the manufacturers of plastics and resins. The use of highly chlorinated Aroclors for extending the kill-life of formulations containing chlordane. aldrin, and dieldrin are mentioned under miscellaneous appli cations of Aroclors. This possibility has been considered in a number of papers. Sullivan and Hornstein (1953). Hornstcin and Sullivan (1953), and Tsao et al. (1953) found that the chlorinated terphsnyl Aro clor 5460 increased the residual persis tence of lindane. Tsao et al. (1953) consid ered that there w-as some indication that chlorinated polyphcnyl may have a syner gistic effect with lindane. Duda (1557) PCB . X XX X X XX X X POSH2LE POINTS FOP SUBSTITUTION Of CHLORINE (A) , l' QIO a-c-c: i. Cl DmOROOlPPENYL Fig. 1. Basic structure of PCBs (A) nd possible rcaclions of PCCs (B). 953 ' . BioScicncc Vol. 20 No. 17 HARTOLDMON0029077 sprayed clni sapling' with a lindane Aro. c!,jr 5-160'mixture (1.4) and then toted -the roidual effect on the leaves to infes tation with elm leaf beetle (Galcritcclla xanthomdacna). He found that leaves treated with lindane plus Aroelor were protected longer and that the insecticidal effect "as more rapid than with lindane alone. Peaks corresponding to Aroelor 5460 have not been detected in the envi ronment. However, under conditions of temperature and flow-rate commonly used for gas chromatographic analysis these compounds would not be detected (Reyn olds, 1970). Nearly 25 years ago it was noted that Aroelor 1242 was one. of 175 compounds out of 6000 tested that was effective against mosquito (Acgyps) larvae (Dconier ct al., 1946). Lichtenstein et al. (1969) tested the effect of adding a variety of biphenyls and terphenyls to DDT and dieldrin with respect to their toxicity to house and fruit flies. It was found that PCBs had very low toxicity to house flies when given alone but PCBs increased the toxicity of dieldrin and DDT. especially the latter. The effectiveness of these com pounds decreased as the' chlorinated level increased. For example. Aroelor 1221 in creased the mortality of fruit flies from 597 to 937b, whereas Aroelor 1268 in creased it to only 777c. Analytical Methods 1) Identification. Since various com pounds with electron-capturing properties have been tentatively identified in atmo spheric samples ir. the past (Abbott et a!., 1966), and some pesticides are capable of hybridizing in the soil to form a new com pound (Bartha, 1969), it is important that the presence of PCBs in field samples be proven beyond doubt. Identification by means of a combination of high resolution gas chromatography and mass spectrom etry has been carried out by three inde pendent laboratories in Sweden (Widmark, 1967), Holland (Koeman et al., 1969a), and the United States (Bagley et al., 1970). Widmurk's report states that all peaks were identified by- mass spectrom etry (although no data were given), but Koeman and co-workers gave full experi mental details, and Bagiev et al. (1970) demonstrated that most chemicals in the eagle samples examined were components of Aroelor 1254. TTius. despite a recent statement by the Monsanto Chemical Company (in Risebrough, 1970) that the case for labeling the peaks in question as PCBs was not proven, there is enough evidence to convince an unbuised scienti fic jury. September I, 1970 2) Separation. The.chemical techniques preliminary to quantitation of residues in samples containing both PCBs and chlo rinated hydrocarbon pesticides fall into two groups - those necessitating the de struction or alteration of one or more of the compounds, and those which do not. Included in the first group is nitration. Treatment with a 1:1 mixture of sulfuric acid nitric acid at 0 C for-5 min destroys or alters aldrin, p.p'-DDL. p.p'-DDD (TDE), p.p'-DDT, and dieldrin such that they can no longer be detected at the original position on the chromatogram. This procedure leaves unaffected PCB, lindane, and BHC (Jensen and Widmark, 1967). A more rigorous nitration with a 1:1 mixture of sulfuric acid-fuming nitric acid for 15 min at room temperature re moves, in addition to DDT and its related products, aldrin, hcptachlor, Kelthane, Perthane, Tedion, Telodrin, and Trithion while lindane, heptachlor epoxide, toxaphene, and Strobane are not removed (Erro et ah, 1967). Risebrough et al. (1969) reported that this nitration also removed the chromatographic peaks of PCBs. Rey nolds (1969) reported that his attempts to nitrate samples were not fully successful in that there appeared to be loss of some of the more volatile PCBs while peaks with longer retention times appeared. Armour and Burke (1969) reported that complex chromatograms resulted after nitration which could not be related to the unreacled DDT-PCB mixture, and nitra tion was not pursued as a practical means of separating DDT and PCB for further tests. Saponification with alcuholic N'aOll or KOH will deity rodrochlorinate Perthane, Toxaphcne, DDD. and DDT to their re spective olefins (Archer and Crosby, 1966: Klein and Watts, 1964). Risebrough ct al. (1969) reported that PCB peaks are not removed or displaced but gave no data. . The second, and in some instances more desirable, group of analytical tech niques allows the special separation of many chlorinated hydrocarbon pesticides from PCBs. Reynolds (1969, 1970) re ported on an activated Florisil column technique which separated hcptachlor, aldrin, DDE, and PCB with the first elu tion (60 ml n-hexane) from lindane; hcp tachlor epoxide, DDD, and DDT with the second elution (40 ml 507) ethyl ether in hexane). Armour and Burke (1970) devel oped a method utilizing a silicic acidCclite column eluting aldrin and PCB with the first fraction (250 ml petroleum ether), and lindane, heptachlor, hepluchlor epoxide, dieldrin, endrin, p.p'- DDE, o,p'-DDT, p.p'-DDT, and p.p'DDD with the second fraction (200 ml acetonitrile hexane methylene chloride-- 1:19:80). Koeman et al. (1969a), using an activated Florisil column, eluted the apolar compounds including DDE and PCB with hexane, and then dieldrin and endrin with I07o diethyl ether in hexane. Mulhern (1968) reported on a method which utilized silica gel-coatcd thin-layer plates Tabu i. Shm sset et pdyeJtlsnreted N'jSrayl* taken Item Mntints Teeknrol Bulletin C/PI-3CS llliill wilfe wVcl feeder is feedor i;i ttvrt ct \ tse .. -- SStteceTMej* Ueqftrt ' Wjtirjl KiUtt Stbytena aerutr Epcxj nt*t Pdtrstsr rcsu - feeder 1241. !2$4 & 1210 (7-8M feodec !2S2 (7M feeder 1221. 1232. 1242 (IISJ feed* 1254 1<1S) feeder T221 & 1241 123*J feeder 1250 [10-15M feeder 12S3 113-20'J . ' SseoruJjr { flmticirrr te sr4v dm tetarrfjnce tnd denied resistance. Ce-p'sstiexrfe te enhance nsisienee. Inp'sva ftfick-tredi end fihet Uir ' . . Prrsnj't-un^Bv* ensure. Incrieic eSef.il*! edliuen resistance toi stfSesne 4*fttiai. CHectfve *cefliic*1 fee rrtrrdrnt. * ktiasat tiienjtb f . fcrt-jljji rr4ui p^Ttstir ream Ntrtpu* {Meiutil rrlic* 1 \ fieeprmc Citfl Ka&ilf . / feed* 1221 (2M feeder 1254 (S-10V Aracier 1254 {!%} feeder 12SI \tZ\l feeder 1253 (1 JM Aredor 1252 {S SOM PUuidm. - tnkencet resistance. flin ectirrfence. *nfte*s dc drier! wa-list; pr*$erBii. htj'irM cbanicrl resistance. f* fl!li!nt tajacttM ecl$t. im }*it Tnaik Tm feeder 1259 115% rf *9 feeder 122 {JM fntprrtt eittf eod tfSrfi resilience Rtiihfi Reret 959 HARTOLDMON0029078 one. a hexanc/cthyl ether (9S.2) solvent system. The plates were developed, sprayed with a silver nitrate solution, and exposed to UV light. The plates were then divided into five horizontal sections. Dicldrin. endrin, 7-BHC, heptachlor epoxide, p.p'-DDD, p.p'-DDT, o,p'DDT, and p,p'-DDE (in that order) were found in the first four fractions, while most of the interfering compounds found in wildlife samples were found in the fifth zone. Baglcy et al. (1970) used this meth od but mentioned that zones three and four contained practically all unknown components as well as p.p'-DDT (zone three) and p,p'-DDE (zone four). Armour and Burke (1969) used precoated (alu minum oxide) sheets and n-heptane and 2% aeetone/n-heptune for solvent sys tems. PCBs (Aroclors 1254 and 1260) and DDE were not separated, but p.p'-DDT and p.p'-DDD were completely sep arated from PCB by both solvent systems. Another possible means of separating in terfering substances is to use a series of differing polarity columns in the gas chro matograph at the time of determination. This is. less time consuming and may be useful when operating conditions can be selected such that PCB peaks arc absent in the region where sought pesticides emerge (Simmons and Tatton, 1967). 3) Quantitation. Kocmun et al. (1969a) semiquantitativcly measured the residues in Japanese quail fed phcnochlor DP6 by using one of the peaks in a phcnochlor DP6 mixture as a standard. Risebrough (1969) quantitated relative levels of PCBs by assuming that each PCB compound produced the same peak height with theelectron capture detector as the same amount by weight of p.p'-DDE. After summing the heights of the individual peaks, the total was multiplied by a factor derived from measurements of standard solutions with electron capture and mierocoulometric detectors. Jensen et al. (1969) reported PCB amounts as the sum of all PCB components and based the estimate .on a combination of mass spectrometry and microcoulomctric and electron cap ture detection. Even with this elaborate approach, these investigators suggest that the method is still rough and may be cor rect only within a factor of 2. Anderson et al. (1969) devised a method for obtaining a crude estimate of PCB residues as Aroclor 1254- from chromatograms where sep-'' aration had not been attempted. On an empirical basis, it was found that Aroclor 1254 could be quantitated by considering peak 10 as p.p'-DDT and multiplying that value by 10. Since this peak had originally been quantitated as p.p'-DDT, and in fact many of the original samples con tained little or no p.p'DDT, it was pos sible to estimate relative PCB values. Anderson and his co-workers also saponi fied samples to remove interfering p.p'DDT and p.p'-T.DC and then quantitated PCBs as Aroclor 1254 by relating sample peaks 9 and 10 to the corresponding peaks of an Aroclor 1254 standard. Reynolds (1970) employed a method similar to Koeman et al. (1969a) but based his quan titation on an average of two or more peaks. In addition, his results were re ported as Aroclor 1254 or 1260 depending on the overall pattern of the' chroma tographic'peak profile. Iris clear that we are still relatively unsophisticated in our PCB quantitation methodology and will continue to estimate only relative amounts of PCBs in field samples until we synthe size the individual PCB components com monly found in the ecosystem and are able to speak in terms of these individual peaks as we do for most pesticide residues. However, it has been kindly pointed out (Risebrough, pers. comm.) that, with ref erence jto biological significance, the cor rect order of magnitude and accurate rela tive amounts of PCB give the essential information. This is because biological effects, such as enzyme induction, are re lated to degree of chlorination, and the existing methods give some indication of this activity. Therefore, that information would be lost if stress were placed only upon quantitating individual peaks. 4) Magnitude oj Error. Ever since PCB peaks were recognized for what they are, residue chemists and other researchers interested in pesticide residues have asked what magnitude of error is likely to result from ignoring the presence of PCBs. Only recently have studies either directly or indirectly resulted in an esti mate of this error. Anderson et al. (1969) quantitated p.p'-DDE, p.p'-DDD, and p.p'-DDT in five egg samples before and after saponification. There was no appre ciable change in the p,p'-DDE, but ap parent p.p'-DDD was reduced by ap proximately 589 and p.p'-DDT by 909. Reynolds (1970) looked at a large number of samples before and after his PCBFlorisil separation and found that the actual p.p'-DDD residue (relative to the apparent residue) represented from 0 to 79 in California gull ([.arus occidentalis) fat, 07c in cormorant (Pkalacrocorax aitritu.t) eggs, SOT in 10 pooled mallard (Anas ptatvrhynchos) duck eggs, and from 0 to 1049 in great blue heron (Ardca cir.crca) eggs. Respective values for p.p'-DDT were 0 to 539, 13 to 41 To, 1007c, and IS to 1029). Actual residue levels, of heptachlor epoxide generally represented a majority of the apparent values. Before and after values for p.p'-DDE and dicldrin were not significantly different. Obviously, the magnitude of error may vary depending on the trophic level sampled and certainly with the area from which a sample is col lected (Risebrough et al., 1968, Jensen et al., 1969). Since the publishing of ade quate separation techniques, there is no reason why there should be any error in pesticide quantitation contributed by PCBs. Toxicology Despite some recent studies, the toxi cology of PCBs remains rather poorlyknown as compared to that of the chlo rinated hydrocarbon pesticides. For ex ample, no definite work has been done to establish LD50 values for the various formulations of PCBs. 1) Acute, single dose experiments. Tucker and Crabtree (1970) found that a single dose of 100 mg/kg Aroclor 1254 (stomach tubed in oil) was fatal to two out of three rats, while 500 mg/kg was not fatal to three rats. Aroclor 1268 killed one rat out of three at 500 mg/kg, 1000 mg/ kg, 2000 mg/kg, and 4000 mg/kg. Smyth (193!) found that a 4 g/kg (degree of chlo rination not stated) was nontoxic to guinea pigs and rabbits, but this appears to be due to the fact that material which was given as a paste passed through the intes tine unubsorbed. Tucker and Crabtree (1970) found that Aroclor 1242, 1254, 1260, and 1268 at a dose of 2000 mg/kg was not fata! to mallard ducks (.four groups of three birds each). 2) Acute, feeding experiments. Mon santo Bulletin 306 states that 100 ppm diet had no effect on rats, although no details of the studies were given. The ex periments of Bennett et al. (1938) in which 0.05 g/rat of 65To chlorine biphenyl was given orally every other day led to 507c mortality. If one assumes a body weight of 200 g, then the alternate day dose is roughly 250 mg/kg, which can be com pared to ora! LD50 for DDT of 113 mg/kg (Frear. 1968). Miller (1944) found that two oral doses of 69 mg of 429 chlorine biphenyl a week apart were fatal to guinea -pigs. At an estimated body weight of 400 g. this gives a dose of 170 mg/kg. Tucker and Crabtree (1970) fed rats diets contain ing 10 and 1000 ppm Aroclor 1254. One rat out of six on the low dose died: this mortality was considered to be due to other causes. Four out of four of the high group died within 53 days and the cal culated intake was 1330-1520 mg/kg. The 960 . BioScicncc Vo!. 20 No. 17 HARTOLDMON0029079 food int-skc of the 1000 'ppm group was on!) 79% of lliu control group. 'Presst ct a!. (1970) have examined the toxicity of Arcelor 1254 to Bengalese finches (Lonchura striata). This is a diffi cult species for which to calculate the dietary intake. Due to their dependence upon unshelled food, it is only possible to present the PCB-Iaden food for a few hours a day (Jefferies, 19G7). Loss by evaporation and loss by spillage must be allowed for, and increase of weight by def ecation must be kept to a minimum. Thus, the calculated dietary intake is sub ject to more error than is usually the case. Presst et al. (1970) also measured the con centration of PCBs in the liver; they found that the range was large (i.c., 70 697 ppm in birds that died compared to 3-634 ppm in those that survived).-These authors conclude that Aroclor 1254 has only 1/13 the toxicity of DDT, although the different shape of the mortality curves--steep with DDT, gradual with PCB--makes comparison difficult. Jef feries and Walker (1966) found good cor relation between calculated dietary intake and liver concentrations for pp'-DDT in the Bengalese finch. However, other workers (Dale et al., 1963; Stickcl et al., 1966; Stickel and Stickel, 1969) have con sidered that levels in the brain arc a more reliable index of toxic levels than those in the liver or whole carcass. De Vos and Koeman (1970) fed Phenoclor DP6, Clophen AGO, and Aroclor 1260 to chickens at a dosage of 400 ppm. Mor tality was complete (20/20) for those birds on Phenoclor in 12-5S days and in 13-29 days for Clophen. The mortality for Aro clor was only 3/20 for a 60-day period. This differential effect is unexplained and is surprising in view of the fact that all three formulations contain 60% chlorine. These workers measured the residue lev els in the liver, and, for some birds, in the brain, for chickens dying during the ex periment. Although there was consider able variation, most of the brain levels were between 210 and 420 ppm, which can be compared to 50-80 ppm for DDT (Stickcl et al., 1966). On the basis of this work, PCB is 1/4-1/5 as toxic as DDT. Little difference was noted between the three different PCB formulations, al though the numbers of determinations involved was rather small. If this finding is borne out by subsequent work, it would suggest that differential absorption from the gut or differentia! penetration of the blood brain barrier is involved. The liver values were more variable. There was a considerable number in the 200-400 ppm range, but there were several values in excess of 2000 ppm. This finding is in agreement with the findings of Dale. Stickel, and co-workcrs that the brain levels are the best indication of acute toxic levels. MoCunc ct al. (I9G2) found no mor tality with chickens fed 100 or 200 ppm Aroclor 1242 in their diet for a 4-wcek period. On diets of 400 ppm ami 800 ppm, the mortalities over a 4-weck period were, respectively, 50% and 90%. During the first 3 weeks, the mortality figures were 10% and 50%, respectively. Flick ct al. (1965), using the same material at 400 ppm in the diet, had three birds out of 24 die in a 3-wcek period. Koeman et al. (1969a) found that a diet containing 2000 ppm Phenoclor DP6 caused complete mortality with Japanese quail (5/5) in 5 13 days and rats (S/8) in 1-56 days. Schoettgcr (unpublished) found that the 96-hr TLm for Aroclor 1221 using cut throat trout was 1.2 mg/1 and for Aroclor 1260 was 60.9 mg/1. In general, they found that the toxicity of Aroclors was inversely proportional to their percentage chlorination and directly proportional to their solubilities. These figures suggest that PCBs are two to three orders of mag nitude less toxic to fish than DDT. Work by Lichtenstein ct al. (1969) on house and fruit flies found that PCBs were 40-300 times less toxic than DDT, the toxicity decreasing as the chlorine content in creases. Thus, it appears that the lower vertebrates and invertebrates are much less susceptible than mammals to direct toxicity from PCBs. 3) Subletka! effects. As with the chlo rinated hydrocarbon pesticides, the most important effects arc long-range sublctha! effects. The pathologic changes in various organs are summarized in Table 2. The tabic shows some interesting differences between mammals and birds. The most striking finds in mammals are alterations to the liver, whereas fluid in the peri cardial sac, kidney damage, and reduced spleen was found in birds. . McLaughlin et al. (1963) found that 25 mg Aroclor 1242 injected into the yolk sac of chicken eggs caused complete mor tality, whereas 10 m-g caused 95% failure and teratogenctic effects were noted among the young that hatched (beak deformity, edema, and growth retardant). Induction of hepatic hydroxylating en zymes has been demonstrated in the pi geon (Riscbrougli et al., 196S). rat (Street et al., 1969). and American kestrel (Falco span'erius) (I.incer and Peakall. 1970). Street and co-workers studied the effects of a diet of 50 ppm and 100 ppm on sleep ing time induced by a standard dose of hexob.irbilal, in vitro rales of aniline hydro\)!ation and demelhylation of p-nilrounKole, and the rate of excretion of dieldrin. These workers studied 10 com pounds ranging in chlorine content from 21% to 68% and found that all the effects increased with increasing chlorine con tent. For example, 50 ppm of Aroclor 1221 reduced hexobarbila! sleeping time by l!%, whereas for Aroclor 1248 and 1268 the figures were, respectively, 35% and 48%. Thus, the sublethal effects have direct correlation with chlorine content, while the lethal effects appear to be in versely correlated (Tucker and Crabtree, in press). Lincer and Peakall (1970) noted an increase of the in vitro rate of metabo lism of estradiol in kestrels fed 0.5 and 5 ppm Aroclor 1254 in their diet and also demonstrated increased levels of cytoplas mic RNA with the higher dietary level using a cytophotomctric technique. Tucker (unpublished) found that a sin gle oral dose of 500 mg/kg Aroclor 1254 caused regular egg laying of Japanese quail (Coturni.x- cotarnix) to turn first to scattered egg production and then to stop completely for a week. The scattered eggs had shells 9% thinner than normal, but thickness returned to control values when regular laying was resumed. Mallard ducks dosed with 1000 mg/kg of Aroclor' laid one or no eggs before stopping for 1 2 weeks. The few eggs laid after the sin gle large dose of Aroclor had shells 18% thinner, and again eggshell thickness was normal after resumption of regular laying. The period before egg laying has been noted to be increased in the ring dove (Peakall, unpublished). It is possible that the mechanism involved is increased-rate of metabolism of circulating estradiol in the liver (Peakall, 1970). Anderson et al. (1969) had suggestive evidence that PCBs affected eggshell thickness, al though to a less extent than DDE. Pre liminary results with ring doves support this conclusion (Peakall, unpublished). Levels of PCBs Found in Nature Roburn (1965), comparing total chlorine (by concentration cell techniques) with results calculated from gas chromatog raphy, found that some unknown chlorine compounds were present in several tissue samples and eggs of wild birds in Great Britain. The first identification of these materials was by Jensen and it is staled (Anonymous, 1966) that residues in feath ers collected in Sweden go back to 1944. PCB residues have been reported in wild life from Canada (Holden and Mursden, 1967: Anderson ct al., 1969; Reynolds, September I. 1970 . 961 HARTOLDMON0029080 TABLE 2. Pathologic changes induced by PCBs Treatment Animal liver Kidney Pericardium and Peritoneum Other Observable Changes References Single cist dose f 69 mg (42% cl) 300 mg daily far $ days [55*i Cl} 50 mg daily for sp to 6 months 5% Cl) . 25.50. & 100 ppm a diet for 15 days (21-63*; C| Aro clots) Guinea Pig Rat Rabbit Rat Rat Rat Small fat droplets through lobules, slight to moderate centra! atrophy, focal necrosis noted in a few animats. Essentially normal Cells swollen, hyaline granules present, most died within few days. Enlarged (33% weight increase). Urge number of hyalins globules krcytoplasm. Several died during experiment. Increase in weight. effect increasing with increasing chlorine content. Aroclor 1232-10%. 1242-12%. 1254 14%. 1268-24?; at 50 ppm. * - . h No noteworthy changes Adrenals, spleen, and pancreas showed no otevrorthy changes. ** .- _ ' Mint! (1914) Bcnnttttt *1.(19381 - Sennelt Street et al. (la press) 100 ppm in diet 200 ppm in diet 400 ppm in diet 800 ppm in diet (Aioctor 1242] Chicken No effect No effect Enlarged and mottled Damaged Damaged - . ' Slight Hydropericardium Hydropericardium Hydropericardium, fcydroperitoneum. Enlarged. McCune et al. (1962) 200 St 400 ppm in diet far 3 weeks (42%. ArodorJ Chicken Na changes noted * Paleness at 200 ppm, extensive Increased fluid in Paleness of pancreas, en Flick >t !. (ISCSI hemorrhage, and enlargement pericardia! sac at the largement of adrenal and fit 400 ppm. higher concentration. smell spleen at low concen trations. At higher concen trations pale crcam-colored pancreas, adrenals hemorrhagic. Various doses (54% Cl. Aroclor) Bengalese Finch No weight changes Weight was 32.4% of brain weight for controls and 53.5% for those dying from PCB poisoning. Slight weight increase, a few showed liquid in pericardial S3C. Presst et al (In press] 400 ppm in diet for 80 days (60% Cl') Chicken Centrolobeler necrosis (compd T and 2}. liver weight increased from 2.76 g/100g to 4.31 g/100 (compd. 3). Fatty degen eration. Tubular dilatation, (compd. 1 and 2) Rare with compd. 3. Kydropericardium common with compds. 1 and 2. Rare with compd. 3. Increased porphyria, spleen small with reduction of red pulp and atrophy of white pulp (compd. ! and 2). Spleen decreased from 3.146 g/1 DO g to 0.136 g/lDCg, compd. 3). Vos and Koeman (In press) *Paractof OP 6 (conpd. 1}. Cbp>r> *53 icon*?! 2} tni liaz'at tZSO (compd. 3) nttt #jtd. (MUmiirf iffecti noted undtf compi ecmbef*. Aiixhrckens ti aeompi I and 2 wrjhia 50 djyj_ only 15N mortiUiy on eompi 3. 1970), .Germany (Fiuczynski and Wend ' land, 1968; Koeman et al., 1967), Great Britain, (Holmes et al., 1967; Presst and Jefferies, 1969; Presst et al., 1970; Holden and Marsden, 1967), Netherlands (Koe- . man et.al., 1967; 1969), Sweden (Anony mous, 1966; Jensen et al., 1969), and the United States (Anderson et a!., 1969; Risebrough et a!., 1968; Risebrough, 1969).. ~- Biological Magnification No detailed studies, such as those for DDD at Clear Lake (Hunt and Bischoff. 1960) and DDT and its metabolites in Lake Michigan (Hickey et al., 1966), have yet been made for PCBs. The most detailed studies currently available are those of Jensen et al. (1969). The figures (mean, range of values, and sample size) given in the table below are taken from their paper. PCBs (ppm in extractable fat) Baltic Stockholm Archipelago Mussel Herring Scat Guillemot eggs 4J (t.9-8.6) (40) 6.S (0.5-23) (18) 34 (16-44) ( 3) 250(I40-360)( 9) 5.2 (3.4-7.0) 5.1 (3.3-8i) 30(16-56) __ (15) (4) ( 3) White-tailed Eagle Pectoral muscle Brain \ 14.000(3400-17.000! ( 4) 910(490-1500) ( 3) Eggs Heron -- V ' 540(250-300) 9400 ( 5) ( I) The levels in three species of fish in Clear Lake in 1968 were 0.03-0.005 ppm (wet weight) compared to C.098 ppm in the breast muscle of a western grebe (Rise brough et al., 1969). Anderson et al. (1969) found that trrmost fish extracts the levels of PCBs were less than 0.1 ppm, whereas the levels in the eggs of cormorants {Phalacrocorax auritiis) were 5-9 ppm. Presst. Jefferies, and Moore (unpublished) found that the livers of fish-eating birds in the British Isles ranged up to a maximum of 900 ppm (wet weight), bird feeders up to 70 ppm, mammal caters to 50 ppm, and insectivores to 1 ppm. Unfortunately, no average values or prey items were in cluded. The physical properties of PCB and the available residue data clearly indicate that these materials arc capable of bio logical magnification up the food chain. 962 BioSctcnce Vol. 20 No. 17 HARTOLDMON0029081 -Ratio or DDT to RGB ' Risebrough ct al. (196S) and Risebrough (1970) have examined the ratio of total DDT. i.e.. DDT and its metabolites to PCB. He has found that the ratio DDT/ PCB was 1-2 in San Francisco Bay and 5 10 for seabirds in the Pacific: in the Gulf of California, a region relatively remote from contamination, the ratio was 9-10. Vermeer (quoted in Reynolds, 1970) in western Canada found a DDE/PCB ratio of 7 for California gull tissues and 13 for great blue heron eggs. In the Baltic the ratio was f-2 (Jensen et al., 1969), al though along the west coast of Sweden the ratio was as low as 0.15. In grebes in the British Isles the ratio was 0.4-0.3 (Presst and Jefferies, 1969). For sea-bird eggs, Presst. et al. (unpublished) found ratios of 0.C6 to 0.5. The overall impression is that the amount of PCB in tissues tends to paral lel that of DDE, at least in local ecosys tems, and the DDE/PCB ratio is lowest near industrial areas suggesting that PCB is not carried quite so readily to remote areas. Nevertheless, the variation of the ratio is small enough to suggest that the routes of dispersal are similar. Since the evidence points to aerial fallout as the route of dispersal of the chlorinated hy drocarbon pesticides (Risebrough et al., 1968; Frost, 1969), it is likely that this is also the main route for PCBs. The path ways by which PCBs escape into the eco system arc poorly known, although the possibilities have been recently discussed at some length (Risebrough, 1970; Rey nolds, 1970). Since a large number of plastics and resins may contain PCBs (Table 1), the most likely route is combus tion of these materials. This supposition remains to be tested. The possibility that PCBs could be derived from DDT should ^Iso-btr considered) TTic possibility that this conversion occurs in tissue is most unlikely for two reasons. First, it has never been detected despite the detailed work on the metabolism of DDT. Second, the only mechanism likely to give rise to a biphenyl is via free radicals and this is unlikely to occur in tissue. However, in the atmosphere under the influence of UV light, such a breakdown is more prob able. A passible reaction is shown in Figure 1. Tautomeric shift could lead to a variety of isomers of dichlorophcnyl, but it is difficult to envision the formation of more highly chlorinated biphenyls by this route. Since PCBs extracted from biological material match well with higher Aroclors (i.e., 1254), it seems unlikely that PCBs found in nature could be derived from other materials. Significance of Current Levels In view of the similarity of PCBs to DDT and its metabolites, the addition of PCB residues to the environment is rough ly equivalent to an increase of DDE resi dues. However,-since a synergistic effect of PCBs on DDT has been demonstrated in insects (Tsuo et al., 1953), this pos sibility should not be overlooked in higher organisms. The enzyme induction effects of PCBs have been well documented, and carbonic anhydrasc inhibition is likely. The effect of PCBs on photosynthesis is a critical experiment that has not been done. Wurster's (1963) experiments with phytoplankton should be repeated with PCBs. . The most critical area for research on PCBs is to discover the major source(s) of escape into the environment. Legislative control of a material escaping as a side effect of its use may have a different set of problems than the control of pesticides which are broadcast as a function of their normal use. The evidence suggests that it is important to find the leak and stop it. Acknow! edgments We are grateful to Dr. Koeman (Uni versity of Utrecht), Drs. Presst and Jef feries (Nature Conservancy, Great Britian). Dr. Reynolds (Ontario Research Foundation), Dr. Street (Utah State Uni versity), and Dr. Tucker (U.S. Fish and Wildiifc Service) for advance copies of important material. Some of the work presented here was carried out under NIH Grant ES00306, Dr. T, J. Cade, Principal Investigator. The review was written while one of us (D.B.P.) was an Established Investigator, American Heart Association. Thanks go to Dr. T. J, Cade for reviewing the manuscript. References . Abbott, D. C., R. B. Harrison, J. O'G. Tatton, and J. Thomson. 1965. Orgunochlorine pesti cides in the atmosphere. Nature. 211: 259 261. . Anderson. D. \V,, J. J. Hickey. R. W. Rise brough. D. F. Hughes, and R. E. Christen sen. 1969. Significance of chlorinated hydro carbon residues to breeding pelicans and / cocmorats. Can. Field Natur.. S3: 89-112. Anonymous. 1966. Report of a new chemical hazard. NevSci.. 32: 612. Archer, T. E.. and D. G. Crosby. 1966. Gas chromatographic measurement of toxaphene in milk, fat, blood, and alfalfa hay. Bull. Environ. Contam. Toxicol.. 1: 70-75. Armour, J., and J. Burke. 1969. Polychlorinated biphenyls as potential interference in pesti cide residue ana!)sis. F.D.A. Laboratory In formation Bull. No. 918. II p. _______ 197U. A method for separating poly chlorinated biphenyls from DDT and its anal ogs./. Assoc. OJJic. Anal. Chcm. (in press). Bagiev. G. E., W. L. Rcichel. and E. Cromartie. 1970. Identification of polychlorinatej bi-. phenyls in two bald eagles by combined gas- liquid chomutography-mass spectrometry. /. Assoc. OJJic. Anal. Chent.. 53: 251-261. Bartha, R. 1969. Pesticide residue interaction " creates hybrid residue. Science. 166: 1299 1300. . Bennett, G. A., C. K. Drinker, and M. F. War ren. L933. Morphological changes in the livers of rats resulting from exposure to ccr- ' tain chlorinated hydrocarbons. /. Ind. Hvg. Toxicol.. 20: 97-123. -' Bourne. W., and C. Mead. 1969. Seabird slaughter. B.T.O. News. No. 36. p. 1-2. Dale, W. E., T. B. Gaines, W. J. Hayes. Jr., and G. \V. Pearce. 1963. Poisoning by DDT; - Re lation between clinical signs and concentra- . tion in rat brain. Science. 142: 1474-1476. Deonier, C. C., H. A. Jones, and H. H. ir.cha. 1946. Organic compounds effective against Anopheles quadrimaculatus. Laboratorytest./. Econ. Entontol.,39: 459-462. Duda. E. J. 1957. The use of chlorinated poly phenyls to increase the effective insecticidal life of lindane./. Econ. Entomol.. 50: 218 219. Erro, F., A. Bevenue. and H. Beckman. 1967. A method for the determination of toxaphene in the presence of DDT. Bull. Environ. Con ' tarn. Toxicol.. 2: 372-380. ' Fiuczynski, V. D., and V. Wendland. 1968. The population of Milvtts m:grans in Berlin 1952 1967./. Ornilhol. '. 109: 462-471. Flick, D. F., R. G..O'Dell. and V. A. Childs. 1965. Studies of the chick edema disease. 3. Similarity of symptoms produced by feeding chlorinated biphenyl. Poultry Sci.. 44: 1460- . 1465. Frear, D. E. H. 1968. Pesticide Handbook- Entoma. College Science Publishers. Frost. J. 1969. Earth, air, and water. Environ ment. II: 15-33. Hickey, J. J.. J. A. Keith, and F. B. Coen. 1966. An exploration of pesticides in a Lake Michi gan ecosystem. /. Appl. Ecol.. 3 (Suppl): 141-154. Holden. A. V., and K. Marsden. 1967. Organo- chlorine residues in seals and porpoises. Nature. 216: 1274-1276. Holmes, D. C., J. H. Simmons, and J. O. 'G. Tatton. 1967. Chlorinated hydrocarbons in British wildlife. Nature. 216: 227-229. Hornstein, 1., and W. N. Sullivan. 1953. The role of chlorinated polyphenyls in improving lindane residues./. Econ. Entomol.. 46: 937 940. Hunt, E. G,, and A. I. Bischoff. 1960. Inimical effects on wildlife of periodic DDD applica tions to Clear Lake. CaliJ. Fish Carne. 45: 91-106. Jefferies, D. J. 1967. The delay in ovulation pro duced by pp'-DDT and its possible signifi cance in the field, ibis. 109: 266-272. - Jefferies, D. J., and C. H. Walker. 1966. Uptake of pp'-DDT and its post-mortem breakdown in the avian liver. Nature. 212: 533-534. Jensen, S., and G. Widmark. 1967. Orgjnoehlo- rinc residues, OECD preliminary study 1906 67. Report given at the OECD Pesticide Conference. Jensen. S., A. G. Johncls, S. Orison, and G. Ottcrlind. 1969. DDT and PCB in marine September !. 1970 ' '- 963 HARTOLDMON0029082 animals from Swcdi-h waters. Nature. 224; 247-250. Klein. A. K,, and J. O. Watt-. 1964. Separation and measurement of Perth.me. DDD (TDL). and DDT in leafy vegetable- by electron capture gas chromatography. J. Assoc. Ojjtc. Anal. Chem.. 47: 311-316. Kceman, J. H.. A. A. G. O-kamp. J. Veen. E. Brouwer. J. Roolh, P. Zurt. E. V. D. Brock, and H. Van Genderen. 1967. Insecticides as a factor in the mortality of the Sandwich tern (Sterna sandvicer.sis). A preliminary communication. Meded. Riijhsfcc. LandbouwKcte.tsch. Cent.. 32: 841-853. Koeman. J. H.. M. C. Ten Noever dc Brauw. and R. H. de Vos. 1969a. Chlorinated, bi phenyls in fish, mussels and birds from the River Rhine and the Netherlands coastal area. Nature. 221:- 1126-112S. Koeman, J. H,, J. A. J. Vink, and J. J. M. de Goeij. 1969b. Causes of mortality in birds of prey and owls in the Netherlands- in the win ter of 1968-1969. Hrdca. 57: 67-76. Lichtenstein. E. P., K. R. Schulz. T. W. Fuhremann. andT. T. Liang. 1969. Biological inter action between plasticizers and insecticides. J. Econ. Eniomol.. bl-. 761-765. Lincer, J. L., and D. B. Pcakall. 1970. Induced hepatic steroid metabolism and increased cytoplasmic R.NA by polychlorinated biphe nyls (PCB) in the American kestrel (Ealco sparverius). Nature (in press). McCune. E. L., J. E. Savage, and B. L. O'Dell. 1962. Hydropcricurdium and ascites in chicks fed a chlorinated hydrocarbon. Poultry Sci.. 41: 295-299. McLaughlin, J.. Jr., G. P. Marliuc, M. J. Verrett, M. K. Mutchler. and O. G. Frilzlaugh. 1963. The injection of chemicals into the yolk sac of fertile eggs prior to incubation as toxicity-test. Toxicol. Appl. Pharmacol. 5: 760-771. Miller, J. W. 1944. Pathologic changes in ani mals exposed to a commercial chlorinated diphenyl. U.S. Pub. Health Rec.. 59: 10S51093. Monsanto Technical Bulletins 0/FL-3I1A. O/PL-306, and O-FF/1. Mulhcrn. B. I9oS. An improved method for the separation and remox jl of orgunuchlorine insecticide- from thin-layer plates. J. Chromatogr.. 34: 556-558. Pcakall. D. B. 1970. Pesticides and the repro duction of birds. Sci. A trier.. 222: 73-78. Penning. C. H. 1930. Pity-real characteristics and commercial possibilities of chlorinated diphenyl. Ind. Eng. Chcm.. 22: I1S0-US2. Pre-sl. I., and D. J. Jefferies, i960. Winter num bers, breeding success, and organochlorine residues in the great crested grebe in Britain. Bird Study, 16: 16S-1S5. PresSt. D. J. Jefferies, and N. W. Moore. 1970. Polychlorinated biphenyls in wild birds in Britain and their avian toxicity. Environ. Pollut. (in press). Reynolds, L. M. 1969. Polychlorobiphenyls (PCBs) and their interference with pesticide residue analysis. Bull. Environ. Contant. Toxi col.. 4: 128-143. 1970. Pesticide residue analysis in the presence of polychlorobiphenyls (PCBs). Residue Rev. (in press). Risebrough, R. W. 1969. Chlorinated hydrocar bons in the global ecosystem. In: Chemical Fallout. G. G. Berg and'.M. W. Miller (Eds.), Charles C Thomas, Springfield. III., p. 5-23. 1970. More letters in the wind. Envi ronment. 12: 16-27. . Risebrough. R. W.. P. Reiche. D. B. Pcakall. S. G. Herman, and M. N. Kirvcn. 196S. Poly chlorinated biphenyls in the global ecosystem. Nature. 220: 1098-1102. Risebrough. R. W., R.Reiche, and H. S. Olcott. 1969. Current progress in the determination of polychlorinated biphenyls. Bull. Environ. Contam. Toxicol.. 4: 192-201. Roburn. J. 1965. A simple concentration-cel!' technique for determining small amounts of halide ions and its use in the determination of residues of organochlorine pesticides. Analyst. 90: 467-475. Schmidt. H.. and G. Shultz. 1SS l. Einwirkung von Fiinffach-Chiorphosphor auf das 7diphenol. Ann. Chem.. 207: 338-344. Simmons, J. H,, and J. O'G Tatton. 1967. Im proved gas chromatographic systems for de termining organochlorine pesticide residues in wildlife. J. Chroiuatogr27: 253-255. Smyth. H. F. 1931, The toxicity of certain ben zene derivatives and related compound-. J. Ind. ffyg. Toxicol.. 13: S7-96. Stickcl, L. F.. W. H. Stickcl. and R. Chri-ten-cn. 1966. Re-idue.s of DDT in brains and bodies of birds that died on dosage and in survivors. Science. 151: 1549-1551. Stickel. L.. and 55 . Stickel. 1969. Distribution of DDT residues in tissues of birds in relation to mortality, body conditions, and lime. Ind. Med. Surg.. 38: 44-53. Street. J. C.. F. M. Urry, D. J. 5Vagstaff. and A. D. Blau. 1969. Comparative effects of poly chlorinated biphenyls and organochlorine pesticides in induction of hepatic microsomal enzyme. Presented at ACS meeting Septem ber 8-12. New York. Sullivan. 55'. N.. and 1. Hornstein. 1953. Chlo rinated polyphenyls to improve lindane resi dues. J. Econ. Eniomol.. 46: 158-159. Tsao. Ching-Hsi. 5V. N. Sullivan, and 1. Horn- stein. 1953. A comparison of evaporation rates and toxicity to house flies of lindane and lindane-chloriatcd polyphenyl deposits. J. Econ. Eniomol.. 46: 8S2-SS4. Tucker. R. K.. and D. G. Crabtree. 1970. Hand book of Toxicity of Pesticides to Wildlife. U-S. Dept, of fnterior. Bureau of Sport Fish eries and Wildlife. Resources Publication No 84. de Vos. J, G.. and J. H. Koeman. 1970. Com parative toxicological study with polychlori nated biphenyls in chickens with special ref erence to porphyria, edema formation. liver necrosis and tissue residues. Toxicol. Appl. Pharmacol, (in press). Widmark. G. 1967. Possible interference by- chlorinated biphenyls. J. Assoc. Offic. Anal. Chem.. 50: 1069. ----------- 1968. Determination of number of com pounds which can result from the chlorination of biphenyl, and development of a simple sys tem by which these may be codified. OECD report Sweden. Wurster, C. F. 1968. DDT reduces photosynthe sis by marine phytoplankton. Science. 159: 1474-1475. '' MICROBIAL CULTURES ' COMPLETE BSCS LISTING! GUARANTEED PURITY! OVER 200 SPECIES AVAILABLE ! ' MOST ORDERS FILLED WITHIN 43 HOURS NOTICE c i=-------o DACTEPL1 and FUEJQI cultures-------- $3.00 per culture . (52.50 per culture for orders of 6 or more cultures) c -o D/iC J nfliOPFIA&Fl--------- S4.00 per 5 ml filtered broth suspensions c -o DACTUPSOPPAPIZ CULTUli'iZ SEZ i S----------Available ot special prices COMPLIMENTARY CULTURES ' One complimentary'culfure (bacterid or Fungal) will be included For each six cultures ordered. ' Compliments may be selected iF so desired. ' Free CATALOGUE OF CULTURES Available Upon Request <fPP.GSQUG IDLE PMZllOGEOLOGICAL ASSOCIATES p.o.dot: eoo/oprAC-o'JS isle, p:r:r;5YLVA?:iA 10505 Telephone 814-533-6373 964 BioScience Vol. 20 No. 17 HARTOLDMON0029083