Document RpBqzE515YxdZo1G3E5M3RYnz

Qrganochlorine Pollutants in Peregrines and Merlins Migrating through Wisconsin Robert W. Risebrouoh Department of Nutritional Scknota InMitutc of Marine Reaourcoa University of California Berkeley, California 94720 ' JREOORY I. Pi orrnt .abortion cf Omiiholopt- t mnrll Jniversiiy. Ithaca. New York IMniel D. Berobr UII N. IcITcrton ' ktllweukK. WiKontln 53201 fhc discovery lhal Ihe Peregrines (Falco pertInto) breeding in the eastern Arctic are laying h|n-shelled eggs and are showing symptoms of Productive failure (Berger ti at., this issue) " that this population is beginning to be the same extinction process that {1C retulteddn the extirpation of breeding Peretlnes in many areas of North America and "Hickey,1969; Ratdilfe, 1970). The r of the eastern United States disap- pearetlbct'fftore Ihe nature of the extinction pro- ttls was evident, but subsequent research unTwwitiihlhhattheegpgoshpeulllatthioinnndinegclinhead(Hbiecekneyasasnod- ' 1968). In Oreat Britain there was iderable amount of evidence that exces- ilve mortality of adult birds had been a major etuon for Ihe rapid decline that began around 9SS, w`Ui Ihe introduction of highly loxic tnsecuctdes such as dieldrin into agricul- ural usefRalcliffe, 1963; Jefferies and Frestt, 966). The surviving birds, however, exper- enced reproductive failures that were charac- lerised by shell dtinnlr.g, egg breakage, and eat- ng of the eggs by the adult birds (Ratdiffe, '967; Ratcliffe, 1970). Although embryonic inortalily may be contributing to Ihe decline in reproductive oapacity of Ihe Ungava Peregrines Berger* 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 ern Canada (Hall, this issue), the United States (Hickey and Andersoe, I960 and Great Britain (Ratcliffe, 1970). At the conference convened in Madison, Wisconsin, by J. J. Hickey in 196S to examine the causes 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 in Peregrine populations in both Europe and North Ameriea (Hickey, 1969). Since repro ductive failure now appears to threaten the survival of the Arctic populations, it hat be come imperative to determine more precisely the particular pollutants responsible. In addition to Ihe evidence relating excessive adult mortality to the use of several of the more toxic of the chlorinated hydrocarbon insecti cides, Ratcliffe (1970) has accumulated a con siderable amount of data relating the shell thinning among British birds of prey to Ihe environmental distribution of organochlorine pollutants, including both insecticides with their derivatives and industrial compounds. The latter consist primarily 6f polychlorinated biphenyls which have become widespread and locally abundant pollutants (Jensen et at., 1969; Koeman et at., 1969; Risebrough el at.. 1961). Other pollutants that might be contribu ting to the decline of the North American Peregrines include mercury and lead. Mercury 247 *m woiMeppnpopi MOMS 0839iq 24S The Canadian Field-Naturalist Vol. 14 Is more Widespread in the environment than was previously suspected (Fimreile ti a!., this issue). Waterfowl may accumulate lead from ingested shotgun pellets (Baglcy and Locke, 1967) and Peregrines preying upon ttiem might acquire dangerous concentrations. There is as yet, however, no evidence that links either metal at environmental concentrations to the shell thinning phenomenon. Proof Is rapidly accumu lating, hqwever, that one or more of the chlor inated hydrocarbons, particularly the DDT compound DDE, may induce shell thinning under both environmental and experimental conditions (Hickey and Anderson, 19(8; Potter and WWmeyer, 1969; Heath n al,, 1969; Anderson tl /., 1969). Very small concentra tions of |DDE are associated with significant changes In shell thickness In eggs of the Brown Pelican (Prlrcanus occidentalb) (Risebrough, Anderson and Schreiber, unpublished observa tions). The role of DDE and of other chlorin ated hydrocarbons found in the environment such as jdieldrin and the polychlorinated bi phenyls ip producing additional sublethal effects that might interfere with reproduction it as yet unclear, belayed breeding or abnormalities in behaviouf could be associated with the high rate of steroid degradation caused by the liver enzymes Induced by these compounds (Jefferies, 1967; Peakall, 1970). The volume that emerged from the I>65 conference in Madison (Hickey, 1969) concludes with the statement by Hickey and Roelle "How much Industrial pollutants like the polychlorinated biphenyls have also contri buted to some of these phenomena promises to be an absorbing chapter in the research of the immediate future" (Hickey and Roelle, 1969). The present paper reports on the polychlorina ted biphenyls and other chlorinated hydro carbons in fat biopsy samples obtained from ten Peregrinc|i and seven Merlins (Pigeon Hawk, Falca nhimbarlut) trapped at the Cedar Grove Ornithological Station on the western shore of Lake Michigan during the fall migrations of 1961 and 1969. Materials and Methods All of the Peregrines were immature birds of the year and therefore approximately three months old. Seven were biopsled in 1964 and three in 1969. All of the Merlin samples were obtained in 1969. Three were adult males, one an adult female, and the remaining three were immatures of the year. The biopsy technique has been described previously (Enderson and Berger, 1964). There have been no indications that this procedure harms the birds in any way. Biopsy samples have been obtained from Harriers (Cirtus cyaneus) that have been observed for many months afterwards (Frances Hamcntrom, per sonal communication). The adipose tissue biopsy templet were frozen, cither in acetone-washed glass vials capped with aluminum foil, or in sterile packet! lined internally with aluminum foil which arc used in medicine for antiseptic gauzes. The samples were weighed in the laboratory to ob tain wet weights and then ground in a Waring blendor with anhydrous sodium sulfate. Lipids were obtained by soxhlet extraction for at least six hours with a hot mixture of two parts of hexane and one part of acetone. The organic solvents were removed by evaporation. When small amounts of sodium sulfate were carried over into the extract, the lipid was dissolved In petroleum ether and washed with water. The biopsy samples were small. The Pere grine samples averaged 0.49 grams, with a range from 0.0496 to 0.94) gm, and the Merlins averaged 0.162 gm, with a range from 0.0497 to 0.5604 gm. Some samples were found to consist mainly of connective tissue rather than lipid. The Peregrine samples consisted of an average of 69% by weight of extractable lipid, with a range from )t% to 91%. One Merlin sample consisted of only 5% lipid, the average percent lipid among the Merlin samples was 15%. and the highest value was 64%. The lipid extracts were dried at 65 for 4-12 hours, weighed in the beakers, dissolved in hexane and divided into one or more aliquots. The aliquot analysed for the DDT and PCB compounds was passed through a modified Davidow column (Stanley and LeFavoure, 1965). This column, consisting of celite, sul furic acid and fuming sulfuric add, permits rapid cleanup with quantitative recov- HONS 083925 m . 14 tnd wr one were ibetf here Jure iptes reus liny per- *ere vliU keu are The obring pMi <ul i of ante ken itod 4ln ere- tins 7 lo wtot pld. M* ha iple .-ent -12 in ou. CB fled JR, Mldill OW- I i Il970 Risebrough bt. AL-: Pollutants in Peregrines and Merlins 249 crin of the DDT compounds and PCB. Although not an Important factor for the present study, it permits much larger amounts of lipid material to be treated at one time than docs the florisil mothod. This procedure, how ever destroys dicldrin and lo determine this compound another method must be employed. Another aliquot of the lipid extract, in hexane, was partitioned twice with acetonitrile, the combined acetonitrile fractions were evaporated In dryness, redissolved In petroleum elher, and pplied to a flnrisii column. The column was rinsed lint with 200 ml of petroleum ether and 100 ml of 6% ethyl ether in petroleum ether. Dieidrin was eluted by passing 200 ml of 15% ethyl elher in petroleum ether through the coi tion. Controls had indicated that 90% or more >f the dieidrin applied to a florisil column eluted n this fraction. Blank samples consisting of redistilled petroeum elher analysed through the entire procelure showed no substances that might interfere with the determination of any of the chlorinated lydrocarbons reported here. The extracts were analysed with a Microtek ichromatograph equipped with a tritium and lckel-6) electron captuR detector. Class mns were used containing )% OF-1, or n IUR of i% QF-1 and 10% DC-200, on omosorb W, 10-100 mesh, acid washed and DS treated. niter laboratories (Reynolds, 1969; Armour Burke, 1970) have developed methods for iraling the polychlorinated biphenyls from e or all of the chlorinated hydrocarbons of insecticide origin. The polychlorinated biphenyl compounds emerge at different times from the gas chromatograph and occasionally a peak may Coincide or interfere with the peak produced by one of the insecticides. We have found it possible, however, to quantify PCB, DDE, p.p'-DDD, p.p'-DDT, dieidrin and endrin on Sa of the procedure outlined above, withatlempt at separating the PCB. Dieidrin >E emerge at exactly the tame limb on -200 column, but on the QF-1 column i no significant interference between and DOB, or between dieidrin and any of the polychlorinated biphenyls encountered in environmental samples. DDE frequently con stitutes 90% or more of the DDT compounds present in wildlife. The electron eaptuR re sponse of DDE it considerably greater than that of PCB, and although one of the PCB compounds emerges at approximately the same time at DDE, the error introduced in the DDE determination it lets than experimental error even when the total PCB concentration it up lo live times that of the DDE. Vermeer and Rey nolds (1970) have commented upon the diffi culty in separating the DDT compounds p.p-DDD and p.p'-DDT from PCB. On the DC-200 column, both DDT compounds emerge at approximately the tame time as t PCB peak (Anderson er of., 1969). On the QF-1 column, however, them it no interference between p.p'DDT and any of the polychlorinated biphenyls usually encountered in environmental samples. Although many different chlorinated biphenyl compounds are released into the environment, relatively few persist in the higher levels of food chains. Moreover, these are found in approxi mately the tame proportions in environmental samples over wide areas of the world. The chromatograms of the PCB compounds in the Peregrines analysed in the present study arc therefore similar lo the chromatograms of Pere grine extracts from Mexico, California, and Amchitka Island (Risebrough, unpublished re sults) . Moreover, the chromatograms are 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 treat the PCB mixture as a single compound and to obtain aocurate relative concentrations of PCB using any one of the several peaks. The peak emerging at the same time as p,p'-DDD on the QF-1 column is almost always of the same height as two of the other peaks, it is therefore possible to obtain a crude estimate of the DDD present without initial separation of the PCB. llils assumption may be tested and the identlflcatioa of p.p'-DDT and p.pf-DDD con firmed by saponification (Andenoo er af,, 1969; Risebrough ef ef,, 1969). Aa aliquot of die m MQNS 003926 250 Thb Canadian Field-Natuxaust ' Vol. 14 extract, in hexane or petroleum ether, It re fluxed in 5 It KOH in ethyl alcohol. The hexane it then sept rated from the alcohol and potassium hydroxide >y the addition of water and a temple Injected In o the (as chromatograph. The pro , cedurc cot vertt both DDT and DDD to their retpective ethylene derivative*, DDE and DDMU, but leaves the PCB profile of the chromatograms unchanged. Since Die profile of the PCB peaks was similar, bur not identical to the profile observed in chromatograms of the commercial prepara tion Aroclof 1254, PCB was quantified by comparing the total area of the PCB peaks emerging alfter DDE with the areas of the tame peaks in chromatograms of standard Aroclor 1254. The procedure it therefore arbitrary, but permits the determination of relative amounts of PCB within the correct order of magnitude of absolute amounts. Moreover, the values ob tained can be readjusted at piethpdology is improved. Results auil Discussion Enderson and Berger (1968 > have previously reported op the chlorinated hydrocarbon resi dues found in biopsy fat samples from immature Peregrines that were alto trapped during ftll migration at Cedar Orove, Wisconsin. These samples, analysed by the Wisconsin Alumni Research Foundation in Madison, Wisconsin, contained Ian average concentration of 19.4 ppm of DDE on a lipid basis. DDE concentra tions in the fat of females at the Arctic breeding grounds are much higher, in the order of 300 ppm or higher (Berger tl of., this issue). The ten Peregrine samples analysed in the present study contelncd 17.9 12.3 ppm DDE, 0.23 0.34 ppm p.pVDDD, 0.71 0.61 ppm p,p'-DDT,llt.t 12 5 ppm total DDT (DDE + p,p'-DD|D + p,p'-DDT), and 52.2 32.3 ppm PCB. Seven samples were analysed for dieldrin, which averaged 0.4Q 0.64 ppm. All 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 jsod p.p'-DDT are lower than those previously repotted by WARP, Inc., presum ably s result of interference by PCB in the earlier determinations (Anderson el el., 1969). The dieldrin values are 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. were 19.3 ppm DDE, 0.8 ppm DDD. 1.2 ppm p.p'-DDT and 0.3 ppm dieldrin (Enderson and Berger, 1968). First year immature Peregrines migrating from the Arctic have therefore low residues of DDE. Unfortunately little is known about the relationships among dietary levels of DDE and PCB, equilibrium concentrations of these com pounds in various tissues, and the limes required to achieve an equilibrium concentration. The low concentrations found in these Peregrines presumably reflect therefore both the age of the birds, which possibly has not permitted them to accumulate the high concentrations found in adults, end lower levels of contamination found in some of the prey species. An understanding of the pharmacodynamics of DDE and PCB in birds is one of the conspicuous deficiencies in our knowledge in the field of pollution ecology. Within several ecosystems so far studied, the concentrations of DDE in birds tends to parallel the concentrations of PCB. The ratio may be approximately one to one, as in San Francisco Bay (Risebrough el al., 1968). DDE is several times more abundant than PCB in several Pacific marine ecosystems (Risebrough er of., 1968), but in Florida, PCB is approximately three times as abundant as DDE in the Brown Pelicans (Risebrough, Grass, Anderson and Schreiber, 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 ap proximately three times. The correlation co- M0NS 083927 ,. 84 , the 49). how leant lipid \RF. . 1.2 atlng M Of t the end comulred The f the Hilo id In ound tdin| :b In et In logy. I.lhe rallel ip be ciwo vet el vertl r of.. utely end eorPCB ictnt. l the iltem it the eecut the oeys- yied, i ap- 1970 RtseaaoooH it. al.: Pollutants in Pcseosmss and Mealins 251 efficient It 0.8897, which is significant at the shell thinning associated with egg breakage, 0.001 level. Although It is not known (torn disappearance of the eggs, and eating of the which area of the Arctic these birds have come, eggs by the adult birds (Ralclfffe, 1970). In the the results suggest that over a considerable area Ungava population of Peregrines in the eastern of the tundra ecosystems occupied by the Pere Arctic, shell thinning and egg breakage are now grines, this ratio reflects the local fallout pattern contributing to reproductive failures (Berger et of DDE and PCB. of., this issue). The evidence svailable to date The four adult Merlins averaged )02 ppm suggests, however, that PCB is not a cause of DDE (139-704) in the lipid fraction. Thle value the shell thinning observed in many populations I may be compared with an 'average concentra of birds. No correlation between thinning and i tion of 292 ppm in the lipid of 9 breeding PCB was found in the eggs of the White Pelican i Peregrines from the Mackenzie River region (Petecanus erytkrorhynckot) (Anderson et at., i (Endcrson and Berger, 1968), 725 ppm jn 1969) or in eggs of the Crest Blue Heron i the fat of four adult Peregrines from Alaska (Antea herodlae) (Vermeer and Reynolds, (Cade el al., 1968) and 334 ppm In the lipid of 1970). An analysis of approximately 200 eggs 9 adult Peregrines from Ungava (Berger el al., of the Brown Pelican from both eastern and i this issue). Merlins therefore may possess al western North America has shown that DDE i most the same level of contamination as the rather than PCB is associated with the shell Peregrines and might therefore be expected to thinning (Risebrough, Cress, Anderson and i thow symptoms of shell thinning. The concen Schreiber, unpublished ms.) Whenever corre trations of total DDT in the adult Merlins lations between PCB and shell thinning have ivtraged 314 ppm. 96% of the DDT residues been observed, as in Double-Crested Cormor I in these Merlins therefore consisted of DDE. ants (Phalacrocorae aurltui), PCB is also cor The PCB concentrations averaged 196 ppm related with DDE (Anderson et al., 1969). (44-467). The samples were not analysed for Peakall (1970) has reported that p.p'-DDT dieldrin. delays egg laying in the Ringdove (Slreptopella In the three immatures, DDE averaged 49.3 rlsoria) and that the delay is associated with ppm (10.8, 18.6 and 119.3), total DDT aver lower concentrations of estradiol in the blood aged 50.3 ppm, and PCB averaged 28.6 ppm early In the breeding cycle. Peakall had earlier i (5.7,29.0 and 51.2). With the exception of one repotted (in Riwbrough et al., 1968) that immature Merlin that contained 18.6 ppm DDE technical DDT, p.p'-DDE, and PCB induce the ind 51.2 ppm PCB, a ratio similar to that found synthesis of liver enzymes that degrade estradiol, m the Peregrines, all other Merlins contained and that PCB Is a more potent enzyme inducer more DDB than PCB. With the one immature than is DDE. Delayed breeding may therefore txcepted, PCB was significantly correlated with be one of the environmental effects of PCB, an i DDB (f = 0.9820, p less than 0.001, four effect that could be critical to Arctic-breeding i Jrgreet of freedom). Most of the Merlins, birds which must complete their reproductive therefore, appear to be coming from a region of cycle within a restricted period of lime. [he boreal forest where the pollutant fallout A recent investigation in Japan of the pattern is different from that in the tundra "Yusho" or Rice Oil Disease has traced the ecosystem occupied by the Peregrine. 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 learned 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 nrith population decline (Rlsebtough el al., drome (Goto el al., 1969). This disease of 1968). The dominant symptom of reproductive chicks wu first observed in the United Statee 'allures of the Peregrines In Britain has been In 1957. and among the sympfoma were accu- MONS 083928 252 The Canadian Field-Naturalist Vol. 14 imilalidn of fluid in the pericardial uc and In Ihc abdominal cavity, subcutaneous edema, and liver and kidney damage (Verrett, 1970). Chlorinated dibenso-p-dioains have been shown to be one of the groups of chlorinated synthetic compounds that produce this disease (Higgin botham ti. af,, 196(1). 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 (Verrcit, 1970). A similar group of compounds, the chlorinated dibenzofurans, an almost las toaic (Schulz, 1970). These resemble the chlorinated biphenyls in structure and might be derived from them. Whether they are now present* in the environment and pose a threat to wildlife promisee to be "an absorbing chapter in the research of the Immediate future" (Hickey and Roelle, 1969). Acknowledgements The research was supported by the National Science Foundation grants OB 6)62 and OB 11649.! Literature Cited . Aadfisen, D. W, HMey, I. f, Mwtraunk, *. W,, Rfi^bis, D. Ft end Chrtrteuneu, IL E. I Ml. Sig nificance of chlorinaled hydrocarbon residues to breeding pelican* and eormoranu. Canadian Field* NalurUit 93(2): 91-112. Anweurl I. As and Sortie. I. A. 1970. Method for separating polychlorinated biphenyl* from DDT and lit inalpp. Journal of the Aieoeiation of Official Anelylkal Chemist* 33: 761-769. Bagtey, |C. E. and Locfce, L. N. 1M7. The occur rence of lead In Ueeues of wild bird*. Bulletin of environmental Contamination and Toabotogy 2: 297-J05. Serfvr. D. Dm Aodereoo, D. W,, Weaver, J. Dm Meebiough, IL W. and SiyeMe, L. M. 1970. ihell lbjnnini in aw* of Ungsva Peregrines. 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Peregrine Falcon Fopulatione: Their Biology and Decline. Univereity. of Wiiconeln Frew. Madieon. 9M pp. Hickey, J. I. and Andireao, D. W. 1961. Chlorin ated hydrocarbons and eggihell changes In raptorial and Ash-eating birds. Science 162: 271-27). Hkkey, J. J. and Roelk, J. E. IM9. Conference summary and conclueiont, in Peregrine Falcon Populations: Their Biology and Decline. J. I. Hkkey. ed. University of Wisconsin Frew. Madbon. pp. 333-567. Higginbotham, G. Rm Huang, Am FWetoM, Dm Vee red, Jm Rm, Jm end Campbell. A. D. 1969. Chemical and toxicological evaluation* of hoisted end synthetk chloro derivatives of dibenao-p-dioain. Nature 220: 702-70). Jefferies, D. I- IM7. The delay in ovulation pr<K ducad by pjk'-DDT end ite possible slgnifkanee In the field, tbh 109: 266-272. Jefferies, D. I. end Preett, I. 1966. Foet-mortemt of Peregrinei and Lanncrs with particular reference to orgenochlorine residues. British Birds 99: 49*64. Jensen, Sm Johotle, A. Cm Otmon, Mm end OtterBnd, G. 1969. DDT end PCS in marine animals from Swedish waters. Nature 224: 247-290. KabublS. 1969. Reports of the Study for "Yuaho" (Chtorobiphenyh Foiaoning). Fukuoka Act* Medics. 60: 407. Kocman, J. Hm Ten Noever de Braow, M. Cm and De Yon, IL' H. 1969. Chlorinated biphenyb in fib. muntli and birdi from the River Rhine end the Netherlands Coastal Area. Nature 221: 1126 1129. . FtakaQ, D. S. 1970. p.p'DDT; Effect on calcium metabolism and concentration of estradiol in the blood. Science 169: 992-994. Porter, It D. and Wbmeyer. S. N. IM9. Dkldrin and DDT: Effects on Sparrow Hawk eggshells and reproduction. Scknce 163: 199-200 RatcBffe, D. A. 1963. The Statue of the Peregrine In Oreat Britain. Bird Study 10: 36-90. Ikaerllffe, D. A- 1967. Decrease in eggshell weight In certain birds of prey. Nature 213: 206-210. KnScUffe, D. A. 1970. Changes attributable to peell- cidee in egg breakage frequency and eggshell thick- twee In eome British' bird*. Journal of Applied Ecology 7: 67-115. l, wwmsminvp^^ MQNS 083929 *1. u IN*. CMMd n lap- i: The PftH. etural- IH9. luctioa Falcon vertiiy. Morinptoriil trine* Eekon I. J. , Vtf. I HI. okttd Jtosin. n promv in MM Of net to 4944. I I I I j l I I I I I 'who* iyh in w and 1124- icitwn ia the ieldrin Us and egrine weight , Mel- | i j I ! > ; ' ! | T 1970 Riseeaouoh it. *L.: Pollutant, in Peaegeines and Merlini 2)1 RrMUA L. M. IN*. Polyclilofofcipficnyt. (PCB't) Mf their Interference with peetkide rteidue analyaii. loumel of Environmental' Contamination and Totkoktgy. 4: 12*14). RkrWowth, It W, Reteht, K TnkM. D. B,, Herman, 8. C, and Khrven, M. N. (Oil. NychloriniOd biphenyls in the (total ecosystem. Nature 220: 1094* 1102. Iktaeih It W,, Refche, f, and OlreCt, H. 8. I HI. Current Erogreee to the determination of the polychlorinated biphenyl*. Bulletin of Environ mental Contamination and Toxicology. 4: 112-201. Behuk, K. H. 1970. Clinical picture and etiology of chloratM. ffrprtoirrf hi: Effect* of 2,4.5,-T on Man and the Environment. Hearing* before the Subcommittee on Bnercy, Natural Reaourcee, and the Environment of the Committee on Commerce, united mate* senate. Serial 9140. U.S. Govern ment Printing Offkc. Washington. DC. Stanley, K L. and UFavova, H. T. IH5. EapM digestion and clean-up of animal thnuct for ptMkide residue analyse, lournal of the Association of Offi cial Analytical Chemist*. 49: 444447. Vtomt, K. >M| R.|mMa L. M. in, Ove.ho* dilorlnc rctMuea I. Mu.lk bird. I. da. CnSiu Pi.irlc Province. Cin.diu FkMN.Iw^M E4: 112-130. Vemtt, J. 1970. Statement before the Subcom mittee on Energy. Natural Resource*, and 8m Environment. In: effect* of 2.4J-T ee Man i * Environment. Serial 9140. VS. C ing Office, Washington. D.C. Received October, 1970 Accepted Octotar, 1970 npiwpapiimFnippRPpmpti^tnnPMMpiiMM M0NS 003930