Selected Organochlorines in Human Blood and Urine in the South of the Russian Far East.

The trace OCP concentrations, such as α-, ß-, and γ-HCH, DDT and its metabolites (DDD and DDE) in blood and urine of residents from the south of the Russian Far East was revealed. A large range of OCPs was found in the urine: α- and γ-isomers of HCH, DDT and DDE. The only ß-HCH was detected in the blood; this indicates its persistence and the difficulty of excretion this substance from the organism. The total trace OCP concentration, found in the biological fluids of residents of the south of the Russian Far East, providing further evidence that these organic contaminants persist in the environment.

DDT, DDE, and 1-hydroxypyrene levels in children (in blood and urine samples) from Chiapas and Oaxaca, Mexico.

The aim of this study was to evaluate the DDT, DDE, and 1-hydroxypyrene exposure levels of children living in communities located in southeastern Mexico. The study communities were Lacanja and Victoria in Chiapas state and Ventanilla in Oaxaca state. Children living in Lacanja had total blood DDT levels (mean ± SD, 29,039.6 ± 11,261.4 ng/g lipid) that were significantly higher than those of children in Victoria (10,220.5 ± 7,893.1 ng/g lipid) and Ventanilla (11,659.7 ± 6,683.7 ng/g lipid). With respect to the 1-hydroxypyrene levels in urine samples, the levels in Lacanja (4.8 ± 4.1 µg/L or 4.5 ± 3.9 µmol/mol creatinine) and Victoria (4.6 ± 3.8 µg/L or 3.9 ± 3.0 µmol/mol Cr) were significantly higher than levels found in Ventanilla (3.6 ± 1.4 µg/L or 2.5 ± 0.5 µmol/mol Cr). In conclusion, our data indicate high levels of exposure in children living in the communities studied in this work. The evidence found in this study could be further used as a trigger to revisit local policies on environmental exposures.

Assessment of the levels of persistent organic pollutants and 1-hydroxypyrene in blood and urine samples from Mexican children living in an endemic malaria area in Mexico.

The aim of this study was to evaluate the exposure levels to persistent organic pollutants and 1-hydroxypyrene in children living in an endemic malaria zone in Mexico. The blood levels for 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and lindane ranged from 15.4 to 17,886.5 ng/g lipid, 6,624.3 to 100,119.0 ng/g lipid, and 351.1 to 6,153.8 ng/g lipid, respectively. For total polychlorinated biphenyls the blood levels ranged from 2,584.9 to 14,547.9 ng/g lipid. Regarding urinary 1-hydroxypyrene levels, the mean level was 2.9 ± 3.1 µmol/mol creatinine. In conclusion, the children in our study are exposed to levels higher than normal to mixtures of environmental contaminants.

2,2-bis(4-Chlorophenyl)acetic acid (DDA), a water-soluble urine biomarker of DDT metabolism in humans.

DDT metabolism in humans yields DDA as the principal urinary metabolite and potential exposure biomarker. A method for DDA analysis in human urine was developed using pentafluorobenzyl bromide and diisopropylethyl amine. Dried hexane extracts were reacted for 1 hour at room temperature. The stable DDA-pentafluorobenzyl-ester derivative was analyzed by gas chromatography-electron capture detector (GC-ECD) and confirmed by gas chromatography-mass spectrometry (GC-MS) in selective ion monitoring mode. The limit of detection for DDA was 0.1 microg/L urine by GC-ECD and 2 microg/L urine by GC-MS, with a relative standard deviation of 12%. Urine specimens from DDT applicators in Swaziland and South Africa were analyzed to evaluate the method. The mean DDA levels during the spray season and post season were 59 and 11 microg/L, respectively. These results must be interpreted cautiously because different groups of workers provided urine specimens in each case. The DDA urinalysis may be a feasible monitoring strategy for low-level occupational and residential DDT exposure assessment in antimalaria campaigns.

Metabolism of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane, and 1-chloro-2,2-bis(p-chlorophenyl)ethene in the hamster.

The urinary metabolites of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), and 1-chloro-2,2-bis(p-chlorophenyl)ethene in female hamsters are reported. The principal metabolite of both DDT and DDD is 2,2-bis(p-chlorophenyl) acetic acid. DDT- and DDD-treated animals also excreted small amounts of DDD, 1-chloro-2,2-bis(p-chlorophenyl)ethene, 1,1-dichloro-2,2-bis-(p-chlorophenyl)ethene, 2-hydroxy-2,2-bis(p-chlorophenyl)acetic acid, and 2,2-bis(p-chlorophenyl)ethanol. 1-Chloro-2,2-bis(p-chlorophenyl)ethene is metabolized to afford significant amounts of 2,2-bis(p-chlorophenyl)acetic acid, 2,2-bis(p-chlorophenyl)-ethanol, 2-hydroxy-2,2-bis(p-chlorophenyl)acetic acid, 2,2-bis-(p-chlorophenyl)acetaldehyde, and 1,1-bis(p-chlorophenyl) ethan-1,2-diol. These results indicate that the metabolic disposition of DDT in the hamster, a species refractory to DDT tumorigenicity, is very similar to that observed previously in the mouse, a species sensitive to DDT tumorigenicity. The one exception is that the hamster is not nearly as efficient as the mouse in converting DDT to 1,1-dichloro-2,2-bis(p-chlorophenyl)ethene, a metabolite that is tumorigenic in both species.

Percutaneous penetration of three insecticides in rats: a comparison of two methods for in vivo determination.

Percutaneous penetration of three insecticides was studied by two methods. The indirect (excretion analysis) and direct (skin patch removal) methods for determining penetration were compared in rats. Radiolabeled solutions of parathion, carbaryl, and DDT were applied to previously shaved rats at the rate of 4 micrograms/cm2. Recoveries of radioactivity in urine, feces, application site, and various tissues were measured at intervals over a 5-day period. Urinary excretion rates were corrected for incomplete excretion by intraperitoneal applications. In the 5 days following intraperitoneal administration, the urinary excretion of parathion and carbaryl was greater than 80% while less than 5% of DDT was excreted. A good correlation was found between the indirect and direct methods utilized to determine percutaneous absorption rates with the compounds tested at the later time intervals. All compounds showed more than 85% dermal penetration within 5 days. At the early time intervals (greater than 24 h), penetration by the direct method was significantly greater for parathion and carbaryl than by the indirect method.

Metabolism of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)-ethane and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane in the mouse.

The metabolites of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD) found in the urine of female Swiss mice are reported. The metabolites of DDT are DDD, 1-chloro-2,2-bis(p-chlorophenyl)ethene (DDMU), 1,1-dichloro-2-bis(p-chlorophenyl)ethene (DDE), 2,2-bis(p-chlorophenyl)acetic acid (DDA), 2-hydroxy-2,2-bis(p-chlorophenyl)acetic acid (alpha OH-DDA) and 2,2-bis(p-chlorophenyl)ethanol (DDOH), while DDD afforded DDMU, DDE, DDA, alpha OH-DDA and DDOH. The relative excreted levels of DDA and DDOH and the absence of 2,2-bis(p-chlorophenyl)acetaldehyde (DDCHO) are not consistent with the generally accepted pathway for DDA formation, which involves sequential metabolism of DDT and DDD via DDOH to afford DDA. The quantitative results are interpreted to mean that DDA is formed by hydroxylation at the chlorinated sp3-side chain carbon of DDD to give 2,2-bis(p-chlorophenyl)acetyl chloride (DDA-Cl), which in turn is hydrolyzed to DDA. The excretion of alpha OH-DDA from both DDT- and DDD-treated mice has never been previously observed. It is suggested that this metabolite arises from the initial epoxidation of DDMU, a metabolite of DDT and DDD, to yield 1,2-epoxy-1-chloro-2,2-bis(p-chlorophenyl)ethane (DDMU-epoxide). This chloroepoxide is then hydrolyzed and oxidized to produce the alpha OH-DDA.

Assessment of DDT, DDE, and 1-hydroxypyrene levels in blood and urine samples in children from Chiapas Mexico.

PURPOSE: The aim of this study was assess co-exposure to DDT, DDE (main DDT metabolite), and PAHs (1-hydroxypyrene) in areas where biomass is used to cook and to heat homes and where DDT was used to combat malaria transmission. METHODS: During 2009, we analyzed a total of 190 blood and urine samples from children living in six communities in Mexico. Quantitative analyses of DDT and DDE were performed using gas chromatography coupled with mass spectrometry. Analyses of 1-hydroxypyrene were performed by HPLC using a fluorescence detector. RESULTS: In this work, we found high levels of DDT and its principal metabolite (DDE) in the blood of children living in four communities in Chiapas located in the southeastern region of Mexico (range,

Colorimetric assay of 2,2-bis(4-chlorophenyl)acetic acid (DDA) in urine.

2,2-Bis(4-chlorophenyl) acetic acid (DDA) was extracted from acidified urine at pH 2 by benzene. It was complexed by partitioning with crystal violet in acetic to yield a blue color which was quantitated at 610 nm. Its identity was confirmed by paper chromatographic separation. The DDA excretion in nine subjects ranged from 0.024 to 0.130 microgram/ml with a mean of 0.065 while that determined by gas chromatography ranged from 0.038 to 0.120 with a mean of 0.069.

[The enzymatic degradation of DDT. 3. Metabolism of DDT]. / Zum enzymatischen Abbau des DDT 3. Mitt. Metabolismus des DDT.

DDT orally given to rats is converted into DDD by reductive dechlorination in the liver within 30 min. 6 h after a single application of 10 mg DDT per rat a quantity of 60 mg DDD/kg was indicated in the liver. DDT is stored in the adrenal glands; in the other organs an equilibrium comes up obviously, even with further application. The quantitative ratios are reported. Information on the experimental details of DDT determination and--anticipatory to the following publications--on the analysis of the most relevant metabolites is given.

DDT residues in human milk samples from Delhi, India.

PIP: Possible contamination of human milk through the excretion of DDT and its metabolites is a concern in India, where DDT is widely used as an insecticide. To assess this risk, milk samples collected from 60 lactating women admitted to hospitals in Delhi were quantitatively analyzed. 55 of the 60 milk samples showed evidence of residues of pp'DDE (mean, 0.176 + or - 0.382 ppm), op'DDT (mean, 0.046 + or - 0.011 ppm), and pp'DDT (mean, 0.122 + or - 0.434 ppm). The mean residue level in milk fat (mg/kg fat) was 7.280 + or - 23.240, 1.428 + or - 2.697, and 1.597 + or - 5.936, respectively. A large variation in individual values was observed. The finding that pp'DDE is the DDT metabolite excreted into human milk at the highest level is consistent with previous research. Daily intake of total DDT averaged 0.062 mg/kg of body weight--a value that is 12 times higher than the acceptable level of DDT (0.005 mg/kg/day) set by the World Health Organization. Although no harmful effects of DDT have been recorded to date in breastfed infants in India, preventive measures aimed at reducing the body burden of DDT in lactating women are urged.^ieng