Pesticides monitoring journal最新文献

Polychlorinated biphenyl (PCB) concentrations in clams (Mercenaria mercenaria) and oysters (Crassostrea virginica) from 17 stations of the western and New Bedford Harbor areas of Buzzards Bay, Massachusetts, clearly show that the New Bedford Harbor area is severely polluted. Up to 5 ppm PCBs (dry weight) were found in shellfish tissue. The most likely sources of the PCBs are chronic releases from two electrical component manufacturers in New Bedford. Close proximity of the shellfish to the source of input is indicated by a high relative abundance of the di-, tri-, and tetrachlorobiphenyls. The data suggest that the New Bedford Harbor area should be considered, along with the Hudson River and Chesapeake Bay, one of the major sources of PCB inputs to the northeastern United States coastal area.

Organochlorine residues in wings of adult mallards (Anas platyrhynchos) and black ducks (Anas rubripes) were monitored nationwide from birds harvested during the 1979-80 hunting season. DDE residues were found in all samples. DDT residues had declined from levels reported in 1976 on a flyway basis but the decline was significant (P less than 0.05) only in the Pacific Flyway. Levels of DDT, DDE, TDE, and dieldrin were low on a flyway basis, and all but DDE declined significantly (P less than 0.05) in the percent occurrence. Polychlorinated biphenyls (PCB) levels were lower in mallard wings from all flyways compared with 1976 data, but percent occurrence had significantly (P less than 0.05) increased. Pools from Alabama and New Mexico continued to show higher DDE residues than pools from other areas.

Milk samples were obtained from 15 nursing mothers in the agricultural region of Comarca Lagunera, Mexico, and were analyzed for organochlorine pesticide residues. Nine different types of residues were found. Of these, p,p'-DDE, p,p'-DDT, and beta-BHC occurred most frequently. All samples had concentrations of DDT-derived compounds higher than the practical limit recommended by the U.N. Food and Agriculture Organization/World Health Organization for DDT in cows' milk. Residues of other chlorinated hydrocarbons were present at levels similar to those found in human milk in other developing countries.

During 1979-80, a total of 236 water samples were collected from 205 sites in South Carolina. Well water, surface water (lakes, ponds, and rivers), and municipal water were sampled and analyzed for the soil fumigant 1,2-dibromo-3-chloropropane (DBCP). DBCP levels ranged from non-detectable to 0.05 microgram/liter (ppb) in an area of nonuse (background). No municipal water samples in the state exceeded the background level. In the area of high use of DBCP, 37% of the surface water samples exceeded the background level, but none exceeded 0.4 microgram/liter. Twenty-seven percent of the well water samples from the high-use area exceeding the background level, and 10.2% of the samples exceeded 1 microgram/liter. All samples exceeding 1 microgram/liter came from a small area within one county. The possible mode of contamination was not determined.

Concentrations of dieldrin and DDT in muscle tissue and fat of carp, Cyprinus carpio, from the Des Moines River, Iowa, differed significantly with month of collection, fish age, and sampling location. Pesticide levels expressed on the basis of wet weight of flesh often differed from those expressed on a fat basis. Fish from reservoirs tended to have higher levels of dieldrin, but not of DDT, than did fish from riverine locations.

Samples of seven species of warmwater fish were collected above, within, and below newly impounded Saylorville Reservoir, Des Moines River, Iowa, from October 1977 to October 1978. Whole-body analyses by gas chromatography were significantly higher in river carpsucker (Carpiodes cyanazine and for the organochlorine insecticides dieldrin, p,p'-DDE, p,p'-TDE, p,p'-DDT, and heptachlor epoxide. Only the organochlorine insecticides were detected in fish tissue. Concentrations of dieldrin and heptachlor epoxide were significantly higher in river carpsucker (Carpiodes carpio) from the reservoir than in those from the river. Other species of fish showed no differences in pesticide concentration related to locality of collection.

DDT residues in soil and earthworms from 50 sites in Delhi were monitored. DDT was detected in all but two samples each of soil and earthworms. Among DDT residues, p,p'-DDE was most common and was found in 48 samples each of soil and earthworms; p,p'-DDT was detected in only 43 soil samples and 46 earthworm samples. p,p'-TDE and o,p'-DDT were also present in smaller concentrations in 29 and 15 soil samples and in 43 and 25 earthworm samples, respectively. Maximum total DDT concentration of 2.6 ppm was detected in the soil from Durga Nagar in the vicinity of a DDT factory. The highest concentration of 37.7 ppm total DDT in earthworms was also obtained from the same site. The maximum concentration factor found in the earthworms was 551. The total DDT concentration in the earthworms and soil showed significant correlation.

Organochlorine insecticides were measured in fish of the Des Moines River, Iowa, in 1977 and 1978 to determine whether concentrations exceeded allowable levels and to compare differences among species. Significant differences in mean concentrations of dieldrin, sigma DDT, and heptachlor epoxide in whole-body samples of seven species of fish, Dorosoma cepedianum, Carpiodes carpio, Cyprinus carpio, Ictalurus punctatus, Pomoxis annularis, Micropterus salmoides, Stizostedion vitreum, could not be adequately explained by body size, position of species in the food chain, or percent body fat.

This study was conducted to determine if dieldrin concentrations in water and fish of the Des Moines River, Iowa, decreased after registration of the compound was withdrawn by the Environmental Protection Agency in 1975. Mean June concentrations of dieldrin in river water decreased from 50 ppt in 1971 to 11 ppt in 1978. Average daily transport of dieldrin was 156 g in 1971 and 70 g in 1978. July levels in channel catfish muscle were 75 ppb in 1973 and 46 ppb in 1978. Dieldrin was still present in significant concentrations in the aquatic system 3 years after registration withdrawal.

Umbilical cord blood collected during labor of 100 Indian women was analyzed for organochlorine pesticides by gas-liquid chromatography with electron-capture detection. Significant levels of p,p'-DDT and its metabolites, p,p'-TDE and p,p'-DDE, as well as alpha-, beta-, and gamma-isomers of BHC were estimated. Residues in the neonatal blood were related to age, dietetic habits, and area of residence of the mothers. The study highlights the extent of placental transfer of the body burden of toxic chemicals from the mother to the fetus.