Levels of organochlorine pesticides in human milk in Ahmedabad,India

Summary Concentrations of organochlorine compounds, i.e., alpha HCH, gamma HCH, beta HCH, p,p'-DDE, p,p'-DDT, o,p'-DDT; p,p'-DDD and PCBs were determined in 50 human milk samples collected in Ahmedabad, India during 1981–1982. The mothers' ages ranged from 18 to 30 years (mean 24 years), and they were nursing their first or second child. All 50 samples contained alpha-HCH, gamma HCH, beta HCH, p,p'-DDE, and p,p'-DDT in a concentration of 17.51, 1.62, 205.48, 244.71, and 53.43, respectively (median g/kg: whole-milk basis). o,p'-DDT was found in 48 samples whereas p,p'DDD was detected in 44 samples. The concentration of o,p'-DDT and p,p'-DDD was 53.43 and 5.13 g/kg (median), expressed on a whole-milk basis. PCBs were absent in all samples.     

有机氯农药暴露与乳腺癌发生关系

目的 研究有机氯农药暴露与乳腺癌发生关系。方法 运用病例对照研究,留取患者的清晨空腹血标本1份约5 mL和术后脂肪组织标本约10 g,标本经处理后,运用气相色谱仪检测病例组(98例)和对照组(79例)血清和乳腺脂肪组织中有机氯农药残留。结果 患者的居住地在病例组与对照组之间差异有统计学意义(χ²=4.70,P=0.03),城市和农村患者血清中β-六氯环己烷(β-HCH)和甲基五氯苯硫醚(PCTA)暴露在病例组与对照组之间差异有统计学意义(OR值分别为2.04、2.07、3.06、3.05,P=0.00);脂肪组织中β-HCH、PCTA和PP'-滴滴伊(PP'-DDE)暴露在病例组和对照组之间差异有统计学意义(OR值分别为3.59、3.62、2.67、2.74、6.68、7.01,P=0.00);雌激素受体(ER)阳性乳腺癌患者血清和脂肪组织中β-HCH、PCTA暴露在病例组和对照组之间差异有统计学意义(OR>1,P<0.05)。结论 有机氯农药暴露可能与乳腺癌发生有关,尤其促使ER阳性乳腺癌的发生。     

Effects of exposure to polychlorinated biphenyls and organochlorine pesticides on thyroid function during pregnancy

In this study, the authors' objective was to determine whether serum concentrations of polychlorinated biphenyls (PCBs), hexachlorobenzene, p,p'-dichlorodiphenyl trichloroethane (DDT), o,p'-DDT, and p,p'-dichlorodiphenyl dichloroethylene (DDE) are associated with thyroid function during pregnancy. These compounds, as well as thyroid-stimulating hormone, total thyroxine, and free thyroxine, were measured in serum samples collected between October 1999 and October 2000 from 334 pregnant women living in the Salinas Valley, California. Data were analyzed by multivariate linear regression. After adjustment for covariates, seven of the 19 PCB congeners detected in more than 75% of participants and the sum of those congeners were negatively associated with free thyroxine concentrations. PCBs 44, 52, and 183 remained significant after the exclusion of two outliers. Hexachlorobenzene concentrations were negatively associated with both free thyroxine and total thyroxine. PCB and hexachlorobenzene concentrations were strongly correlated, which hampered the authors' ability to identify their independent associations with thyroid function. None of the exposures under study were associated with thyroid-stimulating hormone. Results suggest that exposure to PCBs and/or hexachlorobenzene at background levels may affect thyroid function during pregnancy. These findings are of particular significance, since thyroid hormones of maternal origin may play an essential role in fetal neurodevelopment.     

Exposure of women to organochlorine pesticides in Southern Spain

Organochlorine pesticides are lipophilic compounds that persist in the environment. Because of their lipid solubility and resistance to metabolism, some of these chemicals accumulate in human tissues. The largest area of intensive greenhouse agriculture in Europe is near the Mediterranean coast of Southern Spain, where this type of farming has greatly expanded since the 1960s. We determined and compared the levels of 15 organochlorine pesticides in the adipose tissue and blood of 200 women living in Southern Spain. Aldrin, dieldrin, endrin, lindane, methoxychlor, endosulfans, and DDT and its metabolites were identified. Detectable concentrations of p,p'-DDE were found in 100% of adipose tissue and serum samples. Among the remaining DDTs, p,p'-DDT was the most common, being detected in 39% of adipose tissue and 76.5% of serum samples, followed by endosulfans I and II, which also were found in both adipose tissue and serum samples but at lower concentrations. Endosulfans were followed in frequency by lindane, aldrin, and dieldrin. Endrin and methoxychlor were present at a much lower frequency compared to those of the other organochlorines. Serum concentrations of p,p'-DDE o,p'-DDD, and endosulfan -I, -sulfate, -lactone, and -diol were significantly correlated with their adipose tissue concentrations. No significant relationships were found between the serum and adipose tissue concentrations of the remaining nine compounds determined, raising doubts about the equivalent use of fat/serum samples for the exposure assessment of some pesticides in epidemiological studies. The results suggested that women of reproductive age in Southern Spain have been and are currently exposed to organochlorine pesticides. Because many of these chemicals can mobilize during pregnancy and lactation, further research is warranted to interpret the health consequences for the children of such exposure.     

Meconium: a matrix reflecting potential fetal exposure to organochlorine pesticides and its metabolites.

This study investigated the suitability of meconium as a matrix to reflect potential fetal exposure to organochlorine and its metabolites. With GC/MS methods, the process for separating and extracting meconium was explored repeatedly. The internal standard method and external standard method were introduced, and the ideal calibration curve (r=0.9885) for p,p'-DDE measurement was obtained with good validity and feasibility. Sixty samples collected during 1997-1998 from the Gynecological and Obstetrical Hospital, University of Rostock, were analyzed. We found three p,p'-DDE-positive samples and confirmed the results with mass spectrometry. Our findings, the first reported in the world, show that there exist residues organochlorine pesticide residue is present in human meconium 25 years after the use of organochlorine ceased. These results suggest that the pollution with organochlorine pesticides is a long-term global public health problem.     

Exposure of young men to organochlorine pesticides in Southern Spain

It has been hypothesized that endocrine disruptors and especially synthetic estrogenic environmental contaminants (xenoestrogens) are etiologic factors in the global decrease of sperm counts and other problems of the male reproductive tract, including cryptorchidism, hypospadias, and testicular cancer. This possibility has prompted research into the current and historical incidence of these diseases. The largest area of intensive greenhouse agriculture in Europe is near the Mediterranean coast of Southern Spain, where this activity has greatly expanded since the 1960s. We determined and compared levels of 14 organochlorine pesticides in the blood of 220 young males in Southern Spain. Aldrin, dieldrin, endrin, lindane, methoxychlor, endosulfans, and DDT and its metabolites were identified. Detectable concentrations of p,p'-DDE were found in 96% of serum samples. Among the remaining DDTs, o,p'-DDD was the most prevalent, detected in 65% of serum samples. Detectable concentrations of endosulfan I or II or their metabolites endosulfan-diol, or -sulfate were found in all samples; endosulfan-diol was the most frequently detected metabolite (92%) followed by sulfate. Results indicate that men of reproductive age in Southern Spain have been and are exposed to organochlorine pesticides. Because many of these chemicals have estrogenic and anti-androgenic activity, further research is warranted to interpret the male reproductive health consequences of this exposure.     

Analysis of breast milk to assess exposure to chlorinated contaminants in Kazakstan: PCBs and organochlorine pesticides in southern Kazakstan.

Organochlorine pesticides (OC) and polychlorinated biphenyls (PCBs) were measured in samples of breast milk taken from 92 donors representative of regional populations in southern Kazakstan. The World Health Organization protocol for assessing levels of chlorinated contaminants in breast milk was followed. The most prevalent OC residues were beta-hexachlorocyclohexane (beta-HCH), p,p'-DDE, p,p'-DDT, hexachlorobenzene, and alpha-HCH. The measured levels of beta-HCH were among the highest reported in the published literature. Data from Aralsk, near the Aral Sea, indicated continuing DDT exposure. Overall PCB-toxic equivalent levels (22 pg/g fat) were similar to those reported in industrialized European countries. PCBs were highest in Atyrau in the Caspian oilfields.     

Levels of organochlorine pesticides and polychlorinated biphenyls (PCBs) in mothers' milk collected in Osaka prefecture from 1969 to 1976

Long-term investigations of polychlorinated hydrocarbon levels in mothers' milk were made from 1969 to 1976. The levels ofp,p-DDE, p,p DDT, dieldrin and PCB in mothers' milk were within the range reported by others. However, -BHC(Hexachlorocyclohexane) levels in the milk were 10 times that found in non-Japanese. A gradual decrease in the -BHC level in the milk was observed during this period. In contrast, the levelsof p,p-DDE,p,p-DDT, dieldrin and PCB were consistent for the 7-year period. A significant correlation between the levels of PCB andp,p-DDE in mothers' milk and blood was observed in the 1974–1976 samples. However, after prohibition of the use of chlorinated hydrocarbons, this relationship was less apparent in the 1972–1973 samples.     

Estimation of long-term exposure to pesticides

Quantifying the exposure of agricultural workers to pesticides is difficult in the face of the heterogeneity of the pesticides used, the variability in methods of application, and the lack of adequate exposure data. This report describes an attempt to estimate long-term dermal and inhalation exposure of bulb farmers by the development of an exposure index. This proposed exposure index consists of generic levels of exposure specific to the method of application, which were derived from databases as well as from field studies. The index is further determined by farm-related parameters such as acreage and number of pesticide applications ascertained from questionnaire responses. A widely used dithiocarbamate mixture served as a marker compound for exposure to other pesticides. Ranking of 127 bulb farmers according to calculated lifetime dermal exposure correlated only moderately to ranking based on duration of exposure, e.g., years of exposure and farm acreage. This finding indicates that the proposed exposure index could provide a useful estimate of long-term exposure to a mixture of pesticides in epidemi-ological investigations.     

Concentrations of organochlorine pesticides in milk of Nicaraguan mothers

Breast-milk samples from 101 mothers from the basin of Rio Aloya, Nicaragua, were collected on two occasions within the first trimester of lactation. Milk samples were analyzed for 13 organochlorine pesticides: (1) p,p'-dichlorophenyldichloroethylene; (2) p,p'-dichlorophenyltrichloroethane; (3) p,p'-dichlorophenyldichlorodiene; (4) alpha-hexachlorocyclohexane; (5) beta-hexachlorocyclohexane; (6) gamma-hexachlorocyclohexane; (7) delta-hexachlorocyclohexane; (8) toxaphene; (9) dieldrin; (10) endrin; (11) aldrin; (12) heptachlor; and (13) heptachlor-epoxide. Organochlorines of the dichlorodiphenylethane class (i.e., p,p'-dichlorodiphenylethane and p,p'-dichlorodiphenylethane) were found in all samples and at the highest mean concentrations observed in the study. Chemicals in the hexachlorocyclohexane family (i.e., alpha- and delta-hexachlocyclohexane) were not found at all (0%), and the other hexachlorocyclohexane compounds (i.e., beta > gamma) were found in less than 6% of the samples. Twenty percent or less of the sample contained chlorInated cyclodienes (i.e., dieldrin > endrin > heptachlor-epoxide > heptachlor). No measurable concentrations of alpha-hexachlorocyclohexane, aldrin, p,p'-dichlorophenyldichlorodiene, and toxaphene were found in the breast milk samples. Analysis of variance demonstrated that only the concentration of p,p'-dichlorophenyldichloroethylene p,p'-dichlorophenyltrichloroethane, and endrin were affected significantly by maternal age. Overall, with the exception of p,p'-chlorophenyldichloroethylene, and p,p'-dichlorophenyltrichloroethane, the mean concentrations of the analyzed pesticides were low. Total p,p'-dichlorophenyltrichloroethane concentrations that exceeded the allowed daily intake set by the World Health Organisation were found in 5.9% of the samples.     

Gas chromatographic determination of organochlorine pesticides in cow milk

A gas chromatographic method of use in determining the following organochlorine pesticides in cow milk has been adapted and validated: α-hexachlorocyclohexane (α-HCH), β-HCH, lindane, δ-HCH, hexachlorobenzene, aldrin, heptachlor, heptachlor epoxide, mirex, 2,4-dichlorodiphenyltrichloroethane (2,4-DDT), 4,4-DDT, 2,4-dichlorodiphenyldichloroethane (2,4-DDD), 4,4-DDD, 2,4-dichlorodiphenylethane (2,4-DDE) and 4,4-DDE. The method studied consists of three steps: the extraction of fat by centrifugation, mixing with anhydrous sodium sulfate, and transfer to a glass column and elution with hexane; purification of the extract via concentrated sulfuric acid treatment; and determination of the organochlorine pesticides by gas chromatography equipped with an electron capture detector. The analytical parameters determined to estimate the quality of the method yielded the following results: correlation coefficients (r) of the calibration curves were greater than 0.996, the variation coefficients of the response factors were less than 4.90%—with the exception of aldrin (5.53%) and lindane (5.75%)—the relative standard deviation of the slope (S_m rel) being ≤1.52%. Zero was included in the confidence limits of the independent term range. The method repeatability and reproducibility values were ≤4.73% and ≤5.79%, respectively. The recovery values of the pesticides analyzed were in the range of 81.92% (α-HCH) to 105.49% (4,4-DDT), except in the case of aldrin and heptachlor epoxide, which yielded recovery values of under 40%. The quantification limits of the method were ≤1 ng/g, with the exception of mirex (5 ng/g).