Document 605OjnQbX9J6mN4jK0Oz69M3

Organochlorine Pollutants in Peregrines and Merlins Migrating through Wisconsin Rom hi \V. Kisi.MROUCII Department of Ntiiiition.il Sciences Infinite of Mannc Resources University of O liforni.i Hcrkclcy. Catifo nia 94720 ` Grigory I. i m< \n r l.fthoralon ( O, milii*t,*rv. * mnrM Univc"'-. itltiu, t. New York Daniri. D. B !*CBR l J2t N. Jcffcrso i Milwaukee, Win imsin 57202 ' The discovery that the Peregrines (/'alvo pere grinus) breedii g in the eastern Arctic arc laying thin-shelled egts and arc showing symptoms of reproductive f; ilurc (Berger et (., this issue) suggests -that this population is beginning to be affected by th; same extinction process that has resulted in the extirpation of breeding Pere grines in man;' areas of North America and Europe (Mickey, 1969; RatclilTc. 1970). The Peregrines of the eastern United States disap peared before the nature of the extinction pro cess was evident, but subsequent research showed that eggshell thinning had been asso ciated with (he population decline (Hickey and Anderson, 1968). In Great Britain there was a considerable amount of evidence that exces sive mortality of adult birds had been a major reason for the rapid decline that began around 1955, coinciding with the introduction of highly toxic insecticides sueh as dicldrin into agricul tural use (Ratcliffc, 1963; JcfTcrics and Prestt, 1966). The surviving birds, however, exper ienced reproductive failures that were charac terized by shell thinning, egg breakage, and eat ing of the eggs by the adult birds (RatelifTc. 1967; RatclilTc, 1970). Although embryonic mortality may be contributing to the decline in reproductive capacity of the Ungava Peregrines (Berger et at., this issue) the pattern of egg breakage associated with shell thinning now observed in this population appears to be iden tical to the symptoms noted previously in south- cm Canada (Hall, this issue), the United State* (Hie1 cy and Anderson, 1968) and Grert Britain (RatclilTc, 1970). At the conference convened in Madison. Wisconsin, by J. J. Hickey in 1965 to examine the cruses of disappearance of the Peregrine from the eastern United States, all conceivable factors were considered in detail. Among these, only environmental pollution was consistent with the pattern of extinction observed m Peregrine populations in both Europe and North America (Hickey. iv69). Since repro ductive failure now appears to threaten the survival of the Arctic populations, it has be come imperative to determine more precise!) the particular pollutants responsible. In addition to the evidence relating excessive adult mortality to the use of several of the more toxic of the chlorinated hydrocarbon insecti cides, RatclilTc (1970) has accumulated a con siderable amount of data relating the shell thinning among British birds of prey to the environmental distribution of organochlorine pollutants, including both insecticides with their derivatives and industrial compounds. The latter consist primarily.of--polychlorinated kiphcnyls which have become widespread and locally abundant pollutants (Jensen et ul. 1969; Koeman et /., 1969; Risebrough et a!.. 1968). Other pollutants that might be contribu ting to the decline of the North American Peregrines include mercury and lead. Mercury 247 i M0NS 082411 248 Titt Canadian Fici.d-Na.uhaijst Vol. 84 is more widespread in the environment than months old. Seven were biopsied in 1968 and was previously suspected (I'itnrcilc rr at., this three in 1969. All of the Merlin samples were issue). Waterfowl may accumulate IrruLfmm obtained in 1969. Three were adult males, one ingested shotgun pellets (Baglcy and Locke, an adult female, and the remaining three were 1967) and PCfcgrmcs preying upon them might immatuics of the year. / acquire dangerous concentrations. There is as The biopsy technique has been described yet, however, no evidence that links either metal previou* ly (f-nderson and Berger, 1968). 7 here at environment; I concentrations to the shell have been no indications that this procedure thinning phenom non. Proof is rapidly accumu harms tic birds in any way. Biopsy samples lating, however, hat one or more of the chlor have bt'en obtained from Harriers (Circus inated hydiocaiuons, particularly the DDT cyancus) that have been observed for many compound DDF, may induce shell thinning, months afterwards (Prances Hamcrslrom, per under bofli" "env ronrbent.M WiT experimental sonal communication). conditions (Hick y and Anderson, 1968; Porter The adipose tissue biopsy samples were and Wiemeyer, 1969; Heath cl al, 1969; frozen, either in acetone-washed glass vials Anderson ct al. 1969). Very small concentra capped with aluminum foil, or in sterile packets tions of DDF a c associated with significant lined internally with aluminum foil which arc changes in shell taickncss in eggs of the Brown used in medicine for antiseptic gauzes. The Pelican (Pclccan (S occidaualis) (Risebrough, samples were weighed in the laboratory to ob Anderson and Schrcibcr, unpublished observa tain wet weights and then ground in a Waring tions). The role )f DDF and of other chlorin blcndor with anhydrous sodium sulfate. Lipids ated hydrocarbons found in the environment were obtained by soxhlct extraction for at least such as dieldrin and the polychlorinated bi six hours with a hot mixture of two pans of phenyls in prodiu ing additional sublcthal cfTccls hexane <nd one part of acetone. The organic that might interfere with reproduction is as yet solvents were icmoved by evaporation. When unclear. Delayed breeding or abnormalities in small amounts of sodium sulfate were earned behaviour could be associated with the high over into the extract, the lipid was dissolved in rate of steroid degradation caused by the liver petroleum ether and washed with water. enzymes induced ny :hcr.e compounds f Jefferies, The biopsy samples mm.i1;. The iVic- 1967; Pcakall, 1970). The volume that emerged grinc samples averaged 0.49 grams, with a range from the 1968 coifcrcncc in Madison (Hickey, from 0.0496 to 0.983 gn>, and the Merlins 1969) concludes with the statement by Hickey averaged 0.162 gm, with a range from 0.0497 to nnd Rocllc "How much industrial pollutants like 0.5608 gm. Some samples were found to consist the polychlorinated biphenyls have also contri mainly of connective tissue rather than lipid. buted to some of these phenomena promises to The Peregrine samples consisted of an average be an absorbing chapter in the research of the of 69 96 by weight of extractable lipid, with a immediate future" (Hickey and Rocllc, 1969). range from 3196 to 91 CP. One Merlin sample /The present paper reports on the polychlorina consisted of only 596 lipid, the average percent ted biphenyls and other chlorinated hydro- lipid among the Merlin samples was 3596. and | carbons in fat biopsy samples obtained from ten the highest value was 6896. ' Pcrcgiincs and seven Merlins (Pigeon Hawk. The lipid extracts were dried at 65 for 8-12 Faico columbarius) trapped at the Cedar Grove hours, weighed in the beakers, dissolved in Ornithological Station on the western shore of hexane nnd divided into one or more aliquots. Lake Michigan during the fall migrations of The aliquot analysed for the DDT and PCB 1968 and 1969. compounds was passed through a modified Materials and Methods Davidow column (Stanley and LeFavoure, 1965). This column, consisting of eelite, sul All of the Peregrines were immature birds of furic acid and fuming sulfuric acid, permits the year and therefore approximately three rapid cleanup with quantitative rccov- MQNS 082412 1970 Rist.iirouch et. al.: Pollutants in Peregrines and Merlins 249 cries of the DDT compounds and PCB. of the polychlorinated biphenyls encountered in Although not an important factor for the environmental samples. DDE frequently con present study, it permits much larger amounts stitutes 90% or more of the DDT compounds of lipid material to be treated at one lime than present in wildlife. The electron capture re docs the florsil method. This procedure, how sponse of DDE is considerably greater than ever destroys dicldrin and to determine this that of PCB, and although one of the PCB compound another method must be employed. compounds emerges at approximately the sa nc Another aliquot of the lipid extract, in hexahe, lime as DDE, the error introduced in the D )E was partitioned twice with acetonitrile, the determination is less than experimental cr or combined acetonitrile fractions were evaporated even when the total PCB concentration is up to to ti\:u*ss, rulissolvcd in petroleum ether, and ftvc times that of the DDE. Vermeer and Rt y- applied to a iI-'Umi column. The column was nolds (1970) have commented upon the diifirinsed first with 200 ml of petroleum ether and cully in separating the DDT compounds p. >' 200 ml of 6% ethyl ether in petroleum ether. DDD and p.p'-DDT from PCB. On the DC-2 )0 Dicldrin was .'luted by passing 200 ml of 15% column, both DDT compounds emerge at ethyl ether in petroleum ether through the col approximately the same time as a PCB pcik umn. Control., had indicated that 90% or more (Anderson et al., 1969). On the QF-l colon n, of the dicldrin applied to a florisil column eluted however, there is no interference between p.p'- in this fraction. DD f and any of the polychlorinated biphen Is Blank samples consisting of redistilled petro usually encountered in environmental sample . leum ether analysed through the entire proce I Although many different chlorinated bipher yl dure showed -to substances (hat might interfere I compounds arc released into the cnvironmci t, with the determination of any of the chlorinated relatively few per^t in hiptw igvrk r>r fo-ai hydrocarbons reported here. '(chains. Moreover, these arc found in approxi The extracts were analysed with a Microtek gas chromatograph equipped with a tritium and a nickci-63 electron capture detector. Glass columns were used containing 3% OF-1, or a mixture of 3% QF-1 and 10% DC-200, on Chromosorb W, 80-100 mesh, acid washed and HMDS treated. Other laboratories (Reynolds, 1969; Armour and Burke, 1970) have developed methods for separating the polychlorinated biphenyls from some or all of the chlorinated hydrocarbons of insecticide origin. The polychlorinated biphenyl mately the same proportions in environment il samples over wide areas of the world. Ti c chromatograms of the PCB compounds in the Peregrines analysed in the present study ate therefore similar to the chromatograms of Pere grine extracts from Mexico, California, and Amchitka Island (Risebrough, unpublished re sults ). Moreover, the chromatograms arc similar to those obtained from extracts of Brown Pelican eggs from several areas in both North and South America (Risebrough. unpublished results). It is frequently possible, therefore, to compounds emerge at different times from the treat the PCB mixture as a single compound gas chromatograph and occasionally a peak may and to obtain accurate relative concentrations coincide or interfere with the peak produced of PCB using any one of the several peaks. The by one of the insecticides. We have found it peak emerging at the same time as p.p'-DDD possible, however, to quantify PCB, DDE, on the QF-1 column is almost always of the p.p'-DDD, p,p'-DDT, dicldrin and endrin on same height as two of the other peaks. It is the basis of the procedure outlined above, with therefore possible to obtain a crude estimate of out any attempt at separating the PCB. Dicldrin the DDD present without initial separation of and DDE emerge at exactly the same time on the PCB. This assumption may be tested and the the DC-200 column, but on the QF-I column identification of p.p'-DDT and p.p'-DDD con there is no significant interference between firmed by saponification (Anderson et al., 1969; dieldrin and DDE, or between dieldrin and any Risebrough et al., 1969). An aliquot of the HONS 062413 250 The Canadian Field-Naturalist Vol. 84 extract, in hexane or petroleum ether, is re* fluxed in 5% KOH in ethyl alcohol. The hexane is then separated from the alcohol and potassium hydroxide by the addition of water and a sample injected into the gas chromatograph. The pro cedure converts both DDT and DDD to their respective ethylene derivatives, DDE and DDMU, but leaves the PCB profile of the chromatograms unchanged. Since the profile of the PCB peaks was similar, but not identical to the profile observed in chromatograms of the commercial prepara tion Aroclor 1254, PCB was quantified by comparing the total area of the PCB peaks emerging after DDE with the areas of the same peaks in chromatograms of standard Aroclor 1254. The procedure is therefore arbitrary, but permits the deter nination of relative amounts of PCB within the correct order of magnitude of absolute amounts. Moreover, the values ob tained can be readjusted as methodology is improved. Results and Discussion Enderson and Berger (1968) have previously reported on the chlorinated hydrocarbon resi dues found in biopsy fat samples from immature Peregrines that were also trapped during fall migration at Cedar Grove, Wisconsin. These samples, analysed by the' Wisconsin Alumni Research Foundation in Madison, Wisconsin, contained an average concentration of 19.4 ppm of DDE on a lipid basis. DDE concentra tions in the fat of females at (he Arctic breeding grounds arc much higher, in the order of 300 ppm or higher (Berger et al., this issue). The ten Peregrine samples analysed in the present study contained 17.9 12.3 ppm DDE, 0.23 0.34 ppm p.p'-DDD, 0.71 0.68 ppm p.p'-DDT, 18.8 * 12.5 ppm totul DDT (DDE 4- p,p'-DDD 4- p.p'-DDT), and 52.2 32.3 ppm PCB. Seven samples were analysed for dicldrin, which averaged 0.40 + 0.64 ppm. AJ1 residues are expressed on an extractable lipid basis, with the 95% confidence limits of the standard error of the mean. The values for p.p'-DDD and p.p'-DDT are lower than those previously reported by WARF, Inc., presutn- ably a result of interference by PCB in the earlier determinations (Anderson tf al.. 1969). The dicldrin values arc equivalent to those previously reported and there is no significant difference in the DDE concentrations, On a lipid basis, the average values reported by WARF. Inc. wera 19.3 ppm DDE, 0.8 ppm DDD, 1.2 ppm p.p'-DDT and 0.3 ppm dicldrin (Enderson and Berber, 1968). First year immature Peregrines migrating from the Arctic have therefore low residues of DDE. Unfortunately little is known about the rclntionswips among dietary levels of DDE and PCB, equilibrium concentrations of these com pounds in various tissues, and the times required to achieve an equilibrium concentration. The low com entrnlions found in these Peregrines presumably reflect therefore both the age of the birds, which possibly has not permitted them to accumulite the high concentrations found in adults, and lower levels of contamination found in some >f the prey species. An understanding of the pharmacodynamics of DDE and PCB in birds is one of the conspicuous deficiencies in our knov ledge in the field of pollution ecology. Within several ecosystems so far studied, the concentrations of DDE in birds tends to parallel the concuntralions of PCB. The ratio may be approximately one to one, as in San Francisco Bay (Risebrough et al., 1968). DDE is several times more abundant than PCB in several Pacific marine ecosystems (Risebrough et al., 1968), but in Florida. PCB is approximately three times as abundant as DDE in the Brown Pelicans (Risebrough, Gress. Anderson and Schrcibcr, unpublished manuscript). The cor relation coefficient between the DDE and PCB concentrations is frequently highly significant. These observations have suggested that the ratios observed reflect the local fallout pattern of the DDT and PCB compounds, and that the DDE and PCB show similar patterns of accu mulation, concentration and excretion in the birds and possibly other members of the ecosys tem. Among the 10 Peregrine samples analysed, PCB was more abundant than DDE by approximatcly three ttmiS. I fie Cbirelatiuit u>- I MUMS 082414 1970 Risurrougm et. al.: Pollutants in Pi-rcgkines and Mi.runs 25, efficient is 0.8897, which is significant at the shell thinning associated with egg breakage, 0.001 level. Although it is not known from disappearance of the eggs, and eating of the which area of the Arctic these hirils have conic, eggs by the adult birds (Ratcliirc, 1970). In the the results suggest that over a considerable area Ungava population rtf Peregrines in the eastern of the toiulra ecosystems occupied by the Pere Arctic, shell thinning and egg breakage are nov grines, this ratio reflects the local fallout pattern contributing to reproductive failures (Berger c of 12121s and PCB. al,, litis issue). The evidence available to dan The four adult Merlins averaged 302 ppm suggests, howeverTthat PCB is not a cause o' POE (139-704) in the lipid fraction. This value ttnTsJ cITlhinning observed in many population, may be compared with an average concentra ^oTHlTds. NcTcotrelationTtetween TKirihinc am1 tion of 392 ppm in the lipid of 9 breeding Peregrines from the Mackenzie River region (Enderson and Berger, 1968), 725 ppm in the (at of four adult Peregrines from Alaska (Cade cl al, 1968) and 334 ppm in the lipid of 9 adult Peregrines from Ungava (Berger et al.. this issue). Merlins therefore may possess al most the sami level of contamination as the Peregrines ani might therefore be expected to show symptoms of shell thinning. The concen trations of total DDT in the adult Merlins averaged 314 ppm. 96% of the DDT residues In these Merlins therefore consisted of DDE. The PCB concentrations averaged 196 ppm TPc/rranufcrytltrorJiynchos) (Anderson et al, 1969 or in eggs of the Great Blue Heron (Artl a licroduv;) (Vermeer and Rcynolcfs. 1970 >. An analysis of approximately 200 eggs of th: Brown Pelican from both eastern ami western North America has shown that DDE rathe- than PCB is associated wTihllic slie'i thTnn na (Kisebrougn. Urcss. Anderson an.I "Schrc bcr, unpublished ms.) Whenever corre lations between PCB and shell thinning hav been observed, as in DoubIc-CTcstcd Cormor ants Phalacrocorax auritus), PCB is also cor related with DDE (Anderson ci al., 1969). (44-467). The samples were not analysed for Pcikall (1970) has reported that p.p'-DDT dicldrin. delays egg laying in the Ringdove (Sirepiopefia I In the three immnturcs. DDE averaged 49.3 risoria) and that the delay is associated will, ppm (10.8, 18.6 and 119.3), total DDT aver lower concentrations of estradiol in the blood i aged 50.3 ppm, and PCB averaged 28.6 ppm early in the breeding cycle. Pcakall had catiicr i (5.7,29.0and 51.2). With the exception of one reported (in Risebrough et al, 1968) Uu immature Merlin that contained 18.6 ppm DDE technical DDT, p.p'-DDE, and PCB induce tin i i and 51.2 ppm PCB, a ratio similar to that found synthesis of liver enzymes that degrade estradiol, i in the Peregrines, aJ) other Merlins contained and that PCB is a more potent enzyme inducer I morg DDE than PCB. With the one immature than is DDE. Delayed breeding may therefore i excepted, TCB was significantly correlated with be one of the environmental effects of PCB. an i DDE (r = 0.9820, p less than 0.001, four effect that could be critical to Arctic-breeding 1 degrees of freedom). Most of the Merlins, birds which must complete their reproductive therefore; appear to be corotTfjf Troni a region or cycle within a restricted period of time. the boreal forest where the potiutanrTalUnrt A recent investigation in Japan of the 'pxrtTcrn is different from that in "iKtT tunara "Yusho" or Rice Oil Disease has traced the ecosystem occupied by th^Pcrcgrinc. ' cause to rice oil contaminated by chlorinated When PCB was found to be present in Pere biphenyls (Katsuki, 1969). Both the contamin grines, occasionally in high concentrations, it ated rice oil and the Japanese commercial PCB seemed likely that these pollutants were con produce symptoms when fed to chicks similar tributing to the reproductive failures associated to those observed in the "chick edema" syn with population decline (Risebrough cl al,, drome (Goto et al, 1969). This disease of 1968). The dominant symptom of reproductive chicks was first observed in the United States failures of the Peregrines in Britain has been in 1957, and among the symptoms were accu- l i i JWI MQNS 0d^Hl5 252 The Canadian Fiei.d-Natukaust Vol. 81 mutation of fluid in the pericardial sac and in the abdominal cavity, subcutaneous edema, and liver and kidney damage (Vcrrclt, 1970). Chlorinated dibenzo-p-dioxins have been shown to be one of the groups of chlorinated synthetic compounds that produce this disease (Higgin botham rf. <//.. 1968). These compounds have also been shown to be present in the herbicide 2.4,5-T and induce both mortality and embry onic deformities in chicks at very low concen trations (Vcit'.w, 1970). A similar group of compound^, the chlorinated dibenzofurans, arc ,almost as toxic (Schulz, J970). These resemble the chlorinated biphenyls in structurfcand~inight be derived from them. Whether hey arc now 'present in the environment and pose a threat to wildlife promises to be "an absorbing chapter I in the research of the immediate future" | (Hickey and koclle, 1969). Acknowledgements The research was supported by the National Science Foundation grants OB 6362 and CB 11649. , Literature Cited * Anderson, O. >V., Hickey. J. J., Riscbroagli, K. W., Hughrs, I). F., nnd Christensen, K. E. 1969. Sig nificance of chlorinated hydrocarbon residues to breeding pelican* uud tuniimaiiis. Canadian FieldNaturalist 83(2): 91-112. Armour, J. A. nnd Burke, J. A. 1970. Method for separating polychlorinated biphenyls from DDT and its analogs. Journal of the Association of Official Annlyticnl Chemists 53: 761-7611. Begley, G. E. and Locke, L. N. 1967. The occur rence of lead in tissues of wild birds. Bulletin of Environmental Contamination and Toxicology 2: 297-305. Berger, l>. D.. Anderson, D. W,, Weaver. J. D., Kiscbrougti, K. W. and Reynolds, L, M. 1970. Shell thinning in eggs of Ungava Peregrines. Cana dian Field-Naturalist 84(3): 265-267. Cade, T. J., White, C. M., and llaugh, J. R. 1968. Peregrines and pesticides in Alaska. Condor 70: 170-178. Enderson, J. II. and Berger, D. D. 1968. Chlorin ated hydrocarbon residues in Peregrines and their prey species from northern Canada: Condor 70: 149*15). Fimrelle, N., Fyfe. K. W,, and Keith, J. A. 1970. Mercury contamination of Canadian Prairie seed eaters and their avian predators. Canadian FieldNaturalist 84(3): 269-276. Goto, M., SokouorM, K., and K. 1969. Hydropericardium assay of rice oil whikh canted Yusho and of Kancchlor 400 in Chickens (in Jap anese tvitb Jinglish abstract). Fukuoka Acta Medica 60: 533-538. Ilall, G. il. 1955. Great moment* in action; 1h* story of the Sun l.fe Falcons. Mercury 1`ress. Montreal (Reprinted in the Canadian Field-Natural ist !4<3>: 21 3-230. Ilrt|.. K. Spann, J. W,, and Kreit/er, J. F. I9f>r Mu.kcd DDF impairment of Mallard reproduction in c >ntrollcd studies. Nature 224; 47-48. IHrkr;, i. J., editor. 1969. Peregrine Falcon Pop ilations; 't heir Biology and Decline. University of Wisconsin Press. Madison. 596 pp. IJirkr;, J, i. and Anderson, D, W. 1968. Chlorin ated hydrocarbons and eggshell changes in raptoria, and fish-eating birds. Science 162; 271-273 Ilirkr, J. J. and Korlle, J. K. 1969. Conference sumnary and conclusions, tn Peregrine l-'alcor Pop-ilalions; Their Biology and Decline. J. J. Hid ey. cd. University of W isconsin Press, Madison pp. 553-567. Higginbotham, G. K., Huang, A,, Firestone, D., Vr, rett, Revs, J., and Campbell, A. I). 1968. Che nical and toxicological evaluations of isolates' and synthetic chloro derivatives of dibcnio-p-dioxin Nature 220; 702-703. JefTerin, I). J. 1967. The delay in ovulation pro ducid by p.p'-DDT and iis possible significance in the ield. Ibis 109; 266-272 Jefferies, I). J. and Presit, I. 1966. Post-mortems of Peregrines and Lanners with particular reference to organochtonne residues. British Birds 59: 49-64. Jensen 5., Johncls, A. G., Olsson, M,, and Oltrrlind. G. 1969. DL)I and PCI! in marine animals from Swedish waters. Nature 224: 247-250. Katxuki, S. 1969. Reports of the Study for "Yusho'* (Chlorohiphcnyls Poisoning). Fukuoka Acta Medica. 60: 407. Kocman, J. IL, Ten Noever it Brauw, M. C., and Dc Vos, K. H. 1969. Chlorinated biphenyls in fish, mussels and birds from the River Rhine and the Netherlands Coastal Area. Nature 221: 1126 1128. ' Peakull, D. B. 1970. p.p'-DDT: Effect on calcium metabolism and concentration of estradiol in the blood. Science 168: 592-594. Porter, R. D. and Wlrroeyer, S. N. 1969. DifJdrin and DDT: Effects on Sparrow Hawk eggshells and reproduction. Science 165: 199-200. Ratchffe, D. A. )963. The tfnius of the Peregrine in Great Britain. Bird Study 10: 56-90. Ratcliffr, D. A. 1967. Decrease in eggshell weight in certain birds of prey. Nature 215; 208-210. Katetiffe, D. A. 1970. Changes attributable to pesti cides in egg breakage frequency and eggshell thick ness in some British' birds. Journal of Applied Ecology 7: 67-115. HUNS 081416 1970 Riseurough et. al.; Pollutants in Peregrines and Merlins 253 Reynolds, L. M, 1969. Polychtorohiphcnyls (PCB's} ml their interference with pesticide residue analysis. Journal of Environment*! Contamination and Toxicology. 4: 128-143. Kischrough, K. W., Rrlrhe, P., Penkill, D. D,, Herman, S. G,, and Klrven, M. N. 1968. Polychlorinated hiplienyls in lhe global ecosystem. Nature 220: 1098* 1102. RUrhrough, R. W., Kriehc, P,, and Oleolt, II. S. 1969. Current Progress in the determination of the polychlorinated biphenyls. Itullctin of Environ* mrniAl Contamination and Toxicology. 4: 192*201. Schulz, K. II, 1970. Clinical picture and etiology of chloracnr. Reprinted in: Effects of 2,4,5,-T on Man and the Environment. Hearings before the Subcommittee on Energy, Natural Resources, and Use Environment of the Committee on Commerce, United States Senate. Serial 91*60. U.S. Govern* ment Priming Office, Washington, DC. Stanley, H. I,, and I^Favoure, II. T. 1965. Rapid digestion and clean-up of animal tissues for pesticide residue analysis. Journal of the Association of Offi cial Analytical Chcmisls. 48: 666-667. Vermeer, K. and Reynolds, I,, M. 1970. Orgaio* cl lorinc residues in aquatic birds in the Caned an Piairie Provinces. Canadian Field-Naturalist 84: IJ7-130. Venrtt, J. 1970. Statement before the Suhcons* m ttce on Energy. Natural Resources, and the Environment. In: Effects of 2.4.3-T on Man and the Et vironmenl. Serial 91-60. U.S. Government Prill ing Office. Washington. D.C. Received October, 1970 Accepted October, 1970 ' MONS 082417