Use of the freshwater clamCorbicula manilensis as a monitor for organochlorine pesticides

Bulletin of Environmental Contamination and Toxicology -     

ECD气相色谱法同时测定多种有机氯和有机磷农药

目的:建立一种用电子捕获检测器同时测定有机氯和有机磷的检测方法。方法:样品中有机磷和有机氯用乙腈提取,混合分散固相萃取净化后采用毛细管柱程序升温,ECD检测器检测。结果:8种有机氯和9种有机磷农药分离良好,回收率72%～103%,RSD为1.9%～7.6%,最低检出浓度0.6μg/kg～3.2μg/kg。结论:用ECD检测器同时对666等8种有机氯和敌敌畏等9种有机磷农药,结果比较满意。     

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).     

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.     

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: alpha-hexachlorocyclohexane (alpha-HCH), beta-HCH, lindane, delta-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 (Sm rel) being < or =1.52%. Zero was included in the confidence limits of the independent term range. The method repeatability and reproducibility values were < or =4.73% and < or =5.79%, respectively. The recovery values of the pesticides analyzed were in the range of 81.92% (alpha-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 < or =1 ng/g, with the exception of mirex (5 ng/g).     

Exposure to organochlorine pesticides is an independent risk factor of hepatocellular carcinoma: A case-control study

Primary hepatocellular carcinoma (HCC) is highly prevalent in China. Although hepatitis B virus (HBV) and aflatoxin B1 (AFB1) are considered the major risk factors, among the high-risk cohorts only a small fraction develops liver cancer. Therefore, we investigated whether organochlorine pesticide exposure contributed to HCC risk in the Xiamen population. The questionnaire database was built from 346 HCC cases and 961 healthy controls during 2007-2009. The serum levels of α-, β-, γ-, δ-HCH, 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane (p,p'-DDT), (1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p'-DDE), 1,1,1-trichloro-2,2-bis (o-chlorophenyl) ethane and 1,1-dichloro-2,2-bis (p-chlorophenyl) ethane were measured by gas chromatography-tandem mass spectrometer, and statistical analysis was done using SPSS16. Significantly, we observed p,p'-DDT and p,p'-DDE, and at the first time β-HCH displayed quartile dose-dependent HCC risk trends; p,p'-DDT showed positive (i.e., synergistic) interactions with HBV, diabetes mellitus, AFB1 and polyaromatic hydrocarbon (PAH) exposure, but negative (i.e., antagonistic) interaction with heavy drinking; p,p'-DDE had positive interaction with PAH but negative interaction with HBV and p,p'-DDT; and β-HCH positively interacted with p,p'-DDT but negatively interacted with heavy drinking and diabetes. p,p'-DDT, p,p'-DDE and β-HCH were independent HCC risk factors. Because of their synergistic interactions with other factors, the high-level exposure combined with common AFB1 and HBV exposure in the investigated area may greatly enhance the risk of HCC.     

Polychlorinated biphenyls and organochlorine pesticides in soils in Poland

The concentrations of organochlorine pesticides such as DDTs, HCHs, CHLs, HCBz and polychlorinated biphenyls (PCBs) were determined in 59 soil samples collected in Poland in 1990-1994 to understand the scale of contamination, spatial distribution and sources of these compounds. Identification and quantification of organochlorines were carried out using HRGC-ECD (63Ni) and HRGC-LRMS. All soil samples were contaminated by DDTs, PCBs and HCHs, while HCBz and CHLs were absent in a few samples. DDTs dominated as organochlorine residues in Polish soil and on the concentration of other insecticides was two orders of magnitude lower. Percentage composition of DDTs (about 60% of p,p'-DDT) indicates a very slow metabolism of DDT in Polish soils. Spatial distribution of HCHs in Poland is similar to distribution of DDTs, while HCBz and CHLs are rather evenly distributed. PCBs concentrations in soil of the Former Soviet Union Army Base are 10 times higher then in urban soils, and 100 times higher then in cultivated and forests soils.     

Interaction behavior of organochlorine pesticides with dissolved Jordanian humic acid

The interaction behavior of Jordanian humic acid isolated from the sediment of King Talal Dam with some chlorinated pesticides (tetradifon, p,p-DDE and p,p-DDT) was studied under different experimental conditions, namely: humic acid concentration, pH, and temperature. The synergistic effect was also studied. The amount of pesticide that did not interact was determined by extraction and analysis by gas chromatography.The interacted amount of pesticide was directly proportional to the concentration of soluble humic acid and inversely proportional to pesticide polarity. There was no significant change in the interacted amount of pesticide with respect to change in temperature. With pH increase, there was a small decrease in the interacted amount of tetradifon, while no changes were detected for p,p-DDE and p,p-DDT.     

Levels of exposure to organochlorine pesticides in open-air dump dwellers

OBJECTIVE: To estimate the degree of internal exposure to organochlorine pesticides (persistent organic pollutants, POP) among inhabitants of an open-air dump. METHODS: This was an observational study with simultaneous measurement and control, in which the criterion for subjects was that they dwelled in an area contaminated by POP and the effect of such contamination was the concentration of such substances into the blood. The study population consisted of 238 people living on an open-air dump in Pil es, in the municipality of Cubat?o, SP, Brazil, and the control population was formed by 258 people, also resident in that municipality, in the Cota 200 district. The following pesticides were analysed: hexachlorobenzene (HCB), p-p'DDT, p-p'DDE, p-p'DDD, o-p'DDT, a HCH (hexachlorocyclohexane); b HCH; g HCH; aldrin; dieldrin; endrin; heptachlor; heptachlor-epoxy and mirex. RESULTS: The average blood level of HCB in Pil es was 4.66 g/l, which was 155 times higher than the average for Cota 200 (0.03 g/l). In Pil es the average blood concentration of total DDT was 3.71 g/l, which was twice the level found in Cota 200 (1.85 g/l). Total HCH presented blood concentrations that were six times greater in Pil es (0.84 g/l versus 0.13 g/l). CONCLUSIONS: A positive association was shown between dwelling in Pil es and the presence of POP in the blood, with much higher risks than in localities without the presence of these contaminants.