RESIDUES
OF ORGANOCHLORINE
POLYCHLORIBIPHENYLS FROM
THE
PESTICIDES
IN STARLINGS
CONTINENTAL
UNITED
AND
( S t u r n u s vulgaris),
STATES,
1982
CHRISTINE M. BUNCK, RICHARD M. PROUTY, and ALEXANDER J. KRYNITSKY U, S. Fish and Wildlife Service Department of the Interior Patuxent Wildlife Research Center Laurel. Maryland 20708 U.S.A.
(Received June 20, 1985) Abstract. Starlings were collected from 129 sites throughout the contiguous United States in the fall of 1982 and analyzed for organochlorine compounds as part of a nationwide monitoring program. Residues of 14 organochlorine compounds were found. Only DDE, polychlorobiphenyls (PCB), dieldrin, and heptachlor epoxide occurred in more than 50% of the 10-starling pools. Geographical variation in the occurrence of seven organochlorine compounds was noted. Mean DDE levels were higher in the southwestern United States. Mean PCB levels were higher in the eastern United States. The occurrence frequency of most organochlorines in 1982 was similar to that which was reported in the previous nationwide study in 1979. A slight increase in occurrence was noted for trans-nonachior. Mean DDE level in 1982was similar to that of 1979. Mean PCB level in 1982was lower than the 1979 mean, but this change may not reflect a decrease in environmental PCB levels.
1. Introduction The nationwide m o n i t o r i n g o f organochlorine residues in starlings (Sturnus vulgaris) in the United States began in 1967-68 (Martin, 1969) by the Fish and Wildlife Service, U.S. D e p a r t m e n t o f the Interior. The purpose o f the p r o g r a m is to evaluate levels and trends o f certain pesticial chemicals in wildlife species. This monitoring p r o g r a m has continued at 2- to 3-yr intervals (Martin and Nickerson, 1972; Nickerson and Barbehenn, 1975; White, 1976, 1979; Cain and Bunck, 1983). The starling was chosen because it is n u m e r o u s , is widely distributed t h r o u g h o u t the continental U.S., and is an o m n i v o r o u s feeder (Feare, 1984). Moreover, residue data f r o m the starling, a terrestrial species, supplement those f r o m the concurrent m o n i t o r i n g effort that examines organochlorine residues in waterfowl wings. We present the results o f the 1982 m o n i t o r i n g effort involving starlings and c o m p a r e these results to those f r o m the 1979 collection.
2. Methods 2.1. STARLING COLLECTION The sampling design o f the 1982 collection was u n c h a n g e d f r o m that described by Martin (1969). Briefly, 10 starlings were shot or t r a p p e d in the fall at each o f I39 sites selected by Martin (1969). These sites were chosen originally by selecting Environmental Monitoring and Assessment 8 (1987) 59-75. 9 1987 by D. Reidel Publishing Company.
60
CHRISTINE M. BUNCK ET AL.
randomly up to four latitude and longitude coordinates within each 5 degree block of latitude and longitude in the contiguous 48 states. When starlings were scarce at a particular site, collectors searched areas near the intended site but remained within the 5 degree block. All starlings collected from a site were wrapped in aluminium foil, placed in a plastic bag, and frozen immediately after collection. Samples were shipped frozen to Patuxent Wildlife Research Center and kept frozen until analysis began. 2.2. CHEMICALMETHODOLOGY All birds were analyzed at the Patuxent Wildlife Reserach Center. If more than 10 starlings were received from a site, 10 were selected randomly for pooling and analysis. If fewer that 10 per site were received, all birds were analyzed. Feet, beaks, wing tips, and skin were removed from each bird and the composite samples were weighed and ground in a Hobart* food chopper/mixer. A smaller Hobart model was used to grind samples when only two or three birds were obtained from a site. Ten g of the tissue homogenate were mixed with sufficient anhydrous sodium sulfate to produce a free-flowing mixture, poured into a 150 x 57 mm glass thimble with an extra coarse fritted disc, and stored overnight in a dessicator. The sample was then extracted with hexane in a Soxhlet extractor for 7 hr. The extract was transferred to a tared flask, evaporated to dryness in a fume hood, and weighed to determine lipid content. This extract was then redissolved in 20 ml of hexane and a 10 ml subsample containing not more than 0.5 g lipid was passed through a partially deactivated 21 g Florisil column (60-100 mesh) to absorb the lipids. The column was prewashed with 50 ml of hexane and the extract eluted with 200 ml of 6~ ethyl ether in hexane. The Florisil eluate was concentrated to 5 ml under an air stream in a hot water bath and a 4 ml subsample was placed on a partially deactivated 2.5 x 23 cm silica gel column (100-200 mesh grade 923) prewashed with 80 ml of petroleum ether. The compounds in the Florisil eluate were collected from the silica gel column in three fractions using the following eluting solvents or solvent mixtures: Fraction 1:400 ml of petroleum ether, contained PCB and DDE Fraction 2:275 ml of 1507o methylene chloride in hexane, contained the remaining organochloride compounds except endrin and dieldrin Fraction 3:200 ml mixture of 1070 acetonitrile, 19070 hexane, and 80070 methylene chloride; contained endrin and dieldrin All samples were analyzed and quantified on a gas-liquid chromatograph equipped with a 1.5~ SP-2250/1.95070 SP-2401 column, an electron capture detector, automatic sampler, and digital processor. Samples were quantified for 14 compounds: p,p'-DDE, p,p'-DDD, p,p'-DDT, dieldrin, heptachlor epoxide, oxychlordane, cis-chlordane, trans-chlordane, transnonachlor, cis-nonachlor, endrin, mirex, hexachlorobenzene (HCB), and PCB. The * Use of trade names does not imply endorsement by the federal government.
ORGANOCHLORINE RESIDUES IN STARLINGS
61
lower limit of reportable residues for pesticides and PCB was 0.01 ppm. Mean recoveries of pesticides and PCB from spiked homogenized grackle (Quiscalus quiscula) tissues ranged from 83-107%, except for trans-nonachlor which was 6007o. Reported values were not corrected for recoveries. Procedural blanks, 1 per 20 samples, were run with solvents through the entire analytical procedure (including extraction, evaporation, column chromatography, and quantification). The residues in a 20-sample group were corrected for any background contamination found. Residues in 15 samples were confirmed with a Finnigan 4000 series gas-liquid chromatograph/mass spectrometer equipped with a 25 m x 0.31 mm internal diameter, cross-linked silicone fused silica capillary column, temperature programmed from 120 ~ for 3 rain then rising to 210 ~ at 4~ m i n - 1. Other operating temperatures were: injector, 230 ~ separator, 235 ~ ion source, 300 ~ 2.3. STATISTICALMETHODS Occurrence of an organochlorine compound was defined as a residue level above the reportable limit of the chemical method. Geometric means were calculated for organochlorines which occurred in at least 50070 of the pools. Analysis of variance (ANOVA) was used to evaluate possible biases introduced into geographical and year comparisons by variation in pool size, collection dates, and percent lipid. Geographical variation of organocholorine compounds which occurred in fewer than 7507o of the pools was evaluated by grouping four adjacent 5 degree blocks to obtain regions which represent 10 degree blocks of latitude and longitude (Figure 1). The northeast, southeast, and south central regions represented more than four of the original 5 degree blocks to include all of Texas, Florida, and New England in the new groupings. For the other organochlorine compounds, geographical variation was evaluated using the original 5 degree blocks and ANOVA techniques. Comparisons to the 1979 collection were done with chi-square tests for organochlorines which occurred in fewer than 7507oof the pools with ANOVA for the other organochlorines. The 5 degree latitude-longitude block was used as a second factor in these ANOVAs. Residue values were log transformed for ANOVA. 3. Results
Starlings were collected at 129 of the original 139 sites and one additional site in block 5-F, which was in the southern tip of Texas. Starlings from the two sites in Louisiana (4-G-3 and 4-G-4) were combined inadvertently and processed as one sample. Although the values obtained from this combined sample may not be directly comparable to past values from either one of the sites, the pool is still representative of starlings found in block 4-G. A total of 129 starling pools was analyzed. The collection of 91~ (118/130) of the pools occurred by the end of December 1982. All but five pools were collected by early January 1983. These pools were typically from sites in the southern portion of the continental United States, such as those in Texas, Georgia, and Florida. Percent lipid differed (P
OF ORGANOCHLORINE
POLYCHLORIBIPHENYLS FROM
THE
PESTICIDES
IN STARLINGS
CONTINENTAL
UNITED
AND
( S t u r n u s vulgaris),
STATES,
1982
CHRISTINE M. BUNCK, RICHARD M. PROUTY, and ALEXANDER J. KRYNITSKY U, S. Fish and Wildlife Service Department of the Interior Patuxent Wildlife Research Center Laurel. Maryland 20708 U.S.A.
(Received June 20, 1985) Abstract. Starlings were collected from 129 sites throughout the contiguous United States in the fall of 1982 and analyzed for organochlorine compounds as part of a nationwide monitoring program. Residues of 14 organochlorine compounds were found. Only DDE, polychlorobiphenyls (PCB), dieldrin, and heptachlor epoxide occurred in more than 50% of the 10-starling pools. Geographical variation in the occurrence of seven organochlorine compounds was noted. Mean DDE levels were higher in the southwestern United States. Mean PCB levels were higher in the eastern United States. The occurrence frequency of most organochlorines in 1982 was similar to that which was reported in the previous nationwide study in 1979. A slight increase in occurrence was noted for trans-nonachior. Mean DDE level in 1982was similar to that of 1979. Mean PCB level in 1982was lower than the 1979 mean, but this change may not reflect a decrease in environmental PCB levels.
1. Introduction The nationwide m o n i t o r i n g o f organochlorine residues in starlings (Sturnus vulgaris) in the United States began in 1967-68 (Martin, 1969) by the Fish and Wildlife Service, U.S. D e p a r t m e n t o f the Interior. The purpose o f the p r o g r a m is to evaluate levels and trends o f certain pesticial chemicals in wildlife species. This monitoring p r o g r a m has continued at 2- to 3-yr intervals (Martin and Nickerson, 1972; Nickerson and Barbehenn, 1975; White, 1976, 1979; Cain and Bunck, 1983). The starling was chosen because it is n u m e r o u s , is widely distributed t h r o u g h o u t the continental U.S., and is an o m n i v o r o u s feeder (Feare, 1984). Moreover, residue data f r o m the starling, a terrestrial species, supplement those f r o m the concurrent m o n i t o r i n g effort that examines organochlorine residues in waterfowl wings. We present the results o f the 1982 m o n i t o r i n g effort involving starlings and c o m p a r e these results to those f r o m the 1979 collection.
2. Methods 2.1. STARLING COLLECTION The sampling design o f the 1982 collection was u n c h a n g e d f r o m that described by Martin (1969). Briefly, 10 starlings were shot or t r a p p e d in the fall at each o f I39 sites selected by Martin (1969). These sites were chosen originally by selecting Environmental Monitoring and Assessment 8 (1987) 59-75. 9 1987 by D. Reidel Publishing Company.
60
CHRISTINE M. BUNCK ET AL.
randomly up to four latitude and longitude coordinates within each 5 degree block of latitude and longitude in the contiguous 48 states. When starlings were scarce at a particular site, collectors searched areas near the intended site but remained within the 5 degree block. All starlings collected from a site were wrapped in aluminium foil, placed in a plastic bag, and frozen immediately after collection. Samples were shipped frozen to Patuxent Wildlife Research Center and kept frozen until analysis began. 2.2. CHEMICALMETHODOLOGY All birds were analyzed at the Patuxent Wildlife Reserach Center. If more than 10 starlings were received from a site, 10 were selected randomly for pooling and analysis. If fewer that 10 per site were received, all birds were analyzed. Feet, beaks, wing tips, and skin were removed from each bird and the composite samples were weighed and ground in a Hobart* food chopper/mixer. A smaller Hobart model was used to grind samples when only two or three birds were obtained from a site. Ten g of the tissue homogenate were mixed with sufficient anhydrous sodium sulfate to produce a free-flowing mixture, poured into a 150 x 57 mm glass thimble with an extra coarse fritted disc, and stored overnight in a dessicator. The sample was then extracted with hexane in a Soxhlet extractor for 7 hr. The extract was transferred to a tared flask, evaporated to dryness in a fume hood, and weighed to determine lipid content. This extract was then redissolved in 20 ml of hexane and a 10 ml subsample containing not more than 0.5 g lipid was passed through a partially deactivated 21 g Florisil column (60-100 mesh) to absorb the lipids. The column was prewashed with 50 ml of hexane and the extract eluted with 200 ml of 6~ ethyl ether in hexane. The Florisil eluate was concentrated to 5 ml under an air stream in a hot water bath and a 4 ml subsample was placed on a partially deactivated 2.5 x 23 cm silica gel column (100-200 mesh grade 923) prewashed with 80 ml of petroleum ether. The compounds in the Florisil eluate were collected from the silica gel column in three fractions using the following eluting solvents or solvent mixtures: Fraction 1:400 ml of petroleum ether, contained PCB and DDE Fraction 2:275 ml of 1507o methylene chloride in hexane, contained the remaining organochloride compounds except endrin and dieldrin Fraction 3:200 ml mixture of 1070 acetonitrile, 19070 hexane, and 80070 methylene chloride; contained endrin and dieldrin All samples were analyzed and quantified on a gas-liquid chromatograph equipped with a 1.5~ SP-2250/1.95070 SP-2401 column, an electron capture detector, automatic sampler, and digital processor. Samples were quantified for 14 compounds: p,p'-DDE, p,p'-DDD, p,p'-DDT, dieldrin, heptachlor epoxide, oxychlordane, cis-chlordane, trans-chlordane, transnonachlor, cis-nonachlor, endrin, mirex, hexachlorobenzene (HCB), and PCB. The * Use of trade names does not imply endorsement by the federal government.
ORGANOCHLORINE RESIDUES IN STARLINGS
61
lower limit of reportable residues for pesticides and PCB was 0.01 ppm. Mean recoveries of pesticides and PCB from spiked homogenized grackle (Quiscalus quiscula) tissues ranged from 83-107%, except for trans-nonachlor which was 6007o. Reported values were not corrected for recoveries. Procedural blanks, 1 per 20 samples, were run with solvents through the entire analytical procedure (including extraction, evaporation, column chromatography, and quantification). The residues in a 20-sample group were corrected for any background contamination found. Residues in 15 samples were confirmed with a Finnigan 4000 series gas-liquid chromatograph/mass spectrometer equipped with a 25 m x 0.31 mm internal diameter, cross-linked silicone fused silica capillary column, temperature programmed from 120 ~ for 3 rain then rising to 210 ~ at 4~ m i n - 1. Other operating temperatures were: injector, 230 ~ separator, 235 ~ ion source, 300 ~ 2.3. STATISTICALMETHODS Occurrence of an organochlorine compound was defined as a residue level above the reportable limit of the chemical method. Geometric means were calculated for organochlorines which occurred in at least 50070 of the pools. Analysis of variance (ANOVA) was used to evaluate possible biases introduced into geographical and year comparisons by variation in pool size, collection dates, and percent lipid. Geographical variation of organocholorine compounds which occurred in fewer than 7507o of the pools was evaluated by grouping four adjacent 5 degree blocks to obtain regions which represent 10 degree blocks of latitude and longitude (Figure 1). The northeast, southeast, and south central regions represented more than four of the original 5 degree blocks to include all of Texas, Florida, and New England in the new groupings. For the other organochlorine compounds, geographical variation was evaluated using the original 5 degree blocks and ANOVA techniques. Comparisons to the 1979 collection were done with chi-square tests for organochlorines which occurred in fewer than 7507oof the pools with ANOVA for the other organochlorines. The 5 degree latitude-longitude block was used as a second factor in these ANOVAs. Residue values were log transformed for ANOVA. 3. Results
Starlings were collected at 129 of the original 139 sites and one additional site in block 5-F, which was in the southern tip of Texas. Starlings from the two sites in Louisiana (4-G-3 and 4-G-4) were combined inadvertently and processed as one sample. Although the values obtained from this combined sample may not be directly comparable to past values from either one of the sites, the pool is still representative of starlings found in block 4-G. A total of 129 starling pools was analyzed. The collection of 91~ (118/130) of the pools occurred by the end of December 1982. All but five pools were collected by early January 1983. These pools were typically from sites in the southern portion of the continental United States, such as those in Texas, Georgia, and Florida. Percent lipid differed (P
