Metabolite Of Dichlorodiphenyltrichloroethane Research Articles

P, p'-Dichlorodiphenyldichloroethylene induces colorectal adenocarcinoma cell proliferation through oxidative stress.

p, p′-Dichlorodiphenyldichloroethylene (DDE), the major metabolite of Dichlorodiphenyltrichloroethane (DDT), is an organochlorine pollutant and associated with cancer progression. The present study investigated the possible effects of p,p′-DDE on colorectal cancer and the involved molecular mechanism. The results indicated that exposure to low concentrations of p,p′-DDE from 10−10 to 10−7 M for 96 h markedly enhanced proliferations of human colorectal adenocarcinoma cell lines. Moreover, p,p′-DDE exposure could activate Wnt/β-catenin and Hedgehog/Gli1 signaling cascades, and the expression level of c-Myc and cyclin D1 was significantly increased. Consistently, p,p′-DDE-induced cell proliferation along with upregulated c-Myc and cyclin D1 were impeded by β-catenin siRNA or Gli1 siRNA. In addition, p,p′-DDE was able to activate NADPH oxidase, generate reactive oxygen species (ROS) and reduce GSH content, superoxide dismutase (SOD) and calatase (CAT) activities. Treatment with antioxidants prevented p,p′-DDE-induced cell proliferation and signaling pathways of Wnt/β-catenin and Hedgehog/Gli1. These results indicated that p,p′-DDE promoted colorectal cancer cell proliferation through Wnt/β-catenin and Hedgehog/Gli1 signalings mediated by oxidative stress. The finding suggests an association between p,p′-DDE exposure and the risk of colorectal cancer progression.

Determination of polychlorinated biphenyls and organochlorine pesticides in small volumes of human blood by high-throughput on-line SPE-LVI-GC-HRMS

A fully automated and robust method featuring on-line solid-phase extraction (SPE) and large volume injection (LVI) gas chromatographic (GC) high resolution mass spectrometry (HRMS) is used to determine polychlorinated biphenyls (PCBs) and organochlorine pesticides, such as penta- and hexachlorobenzene (PeCBz, HxCBz), hexachlorocyclohexane isomers (HCH) and 4,4'-dichlorodiphenyldichloroethene (a metabolite of dichlorodiphenyltrichloroethane (DDT)), with only 200μl of human blood, serum or plasma. After spiking the sample with (13)C-labeled internal standards and precipitating the proteins, the sample is passed through a 10mm×2.0mm ID SPE cartridge filled with C18 material that adsorbs the analytes. After washing and drying, the cartridge is extracted with hexane/dodecane (99/1, v/v); the extract is directly injected into a LVI where GC/HRMS analysis follows. The fully automated system utilizes a robotic autosampler and a modular SPE system including two high-pressure syringe pumps, an automatic SPE cartridge exchanger unit and 6 switchable valves. All sample preparation steps are performed within 20min during the GC run of a previous sample, limiting the throughput with only the GC runtime. The contents are quantified using the isotope dilution method. Due to laboratory air contamination problems, we achieved LOQs of 0.017 (PeCBz), 0.009 (HxCBz), 0.007 (HCH), 0.016 (DDE), while for the six indicator PCBs, we achieved values of 0.030 (PCB-28), 0.044 (PCB-52), 0.024 (PCB-101), 0.009 (PCB-138), 0.015 (PCB-153) and 0.008 (PCB-180)μg/l serum. Under clean laboratory air conditions, these values may be improved. This method is recommended when high throughput is desirable and/or only small amounts of material are available, such as during studies involving children.

Quantitative analysis of organochlorine pesticides in human serum using headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry

Persistent organochlorine pesticides (OCPs) are well known to accumulate in environment and to instigate disruptions in endocrine system. In the present study, 18 kinds of OCPs were bio-monitored from 1904 adult serums. Analysis was performed with headspace gas chromatography (HS-GC) which has the advantage to require small volume of serum (1mL) without complex pretreatment and 13C isotope labeled internal standard mix was used for quantitation. As a result, eleven out of 18 OCPs, including hexachlorobenzene (HCB) and dichlorodiphenyltrichloroethane metabolites (DDTs) were detected. HCB was the most frequently detected OCP (8.0%) with an average concentration of 1.74ngg−1 lipid (2.10ngg−1 lipid–99.80ngg−1 lipid). p,p′-Dichlorodiphenyldichloroethylene (p,p′-DDE) had the highest average concentration of 21.65ngg−1 lipid (12.80ngg−1 lipid–2270ngg−1 lipid) and was detected from 7.5% of serum samples. The average concentration of ∑DDT metabolites was 32.04ngg−1 lipid (6.61ngg−1 lipid–2800ngg−1 lipid) with detection frequency of 9.0%. Results interpreted with respect to age groups showed increase in ∑OCPs and ∑DDTs concentrations as age increases, except for the 20. Results interpreted with respect to gender, in general, illustrated higher detected concentration of OCPs in male serums than in female serums; however, the result trend was reversed in age group of the sixties. The above results will be applicable to health impact assessment of Koreans in relation to environmental contaminations.

Parental exposure to natural mixtures of POPs reduced embryo production and altered gene transcription in zebrafish embryos

Determination of toxicity of complex mixtures has been proposed to be one of the most important challenges for modern toxicology. In this study we performed genome wide transcriptome profiling to assess potential toxicant induced changes in gene regulation in zebrafish embryos following parental exposure to two natural mixtures of persistent organic pollutants (POPs). The mixtures used were extracted from burbot (Lota lota) liver originating from two lakes (Lake Mjøsa and Lake Losna) belonging to the same freshwater system in Norway. The dominating groups of contaminants were polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane metabolites (DDTs). Because both mixtures used in the present study induced similar effects, it is likely that the same toxicants are involved. The Mjøsa mixture contains high levels of PBDEs while this group of pollutants is low in the Losna mixture. However, both mixtures contain substantial concentrations of PCB and DDT suggesting these contaminants as the predominant contributors to the toxicity observed.The observed effects included phenotypic traits, like embryo production and survival, and gene transcription changes corresponding with disease and biological functions such as cancer, reproductive system disease, cardiovascular disease, lipid and protein metabolism, small molecule biochemistry and cell cycle. The changes in gene transcription included genes regulated by HNF4A, insulin, LH, FSH and NF-κB which are known to be central regulators of endocrine signaling, metabolism, metabolic homeostasis, immune functions, cancer development and reproduction. The results suggest that relative low concentrations of the natural mixtures of POPs used in the present study might pose a threat to wild freshwater fish living in the lakes from which the POPs mixtures originated.

Evaluating contamination in the Red-billed Chough Pyrrhocorax pyrrhocorax through non-invasive sampling

Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs), 19 polybrominated diphenyl ethers (PBDEs), 7 polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), isomers and metabolites of dichlorodiphenyltrichloroethane (DDTs) and Hexachlorocyclohexane (HCHs) were measured in the feathers of the Red-billed Chough Pyrrhocorax pyrrhocorax, a rare and protected corvid species inhabiting rural and mountainous areas. Feathers were collected in the wild from seven sites in the Iberian Peninsula, one in La Palma, Canary Islands, Spain and one site in Italy. HCH isomers and HCB resulted always under the detection limit. PAHs were found only in the Italian population (range 39.3–54.6ng/g wet weight in the three subsamples). For PBDEs, the concentrations ranged from 135 to 11,753pg/g (mean 1560±3415pg/g w.w.). Only one sample collected in the most urbanized Spanish site in 1990 exceeded 2000pg/g. Twenty years later in the same site the concentration resulted very low. Six Spanish areas from the same meta-population, and one island population at La Palma showed a low contamination by pp'DDE (3.2±3.3ng/g w.w., range for positive samples 1.7–10.1ng/g w.w.). PCBs were found only in two Spanish locations with the 52 and the 138 congeners. Overall the species showed low to intermediate levels of contamination in feathers probably due to its intermediate trophic position and/or to the integrity of its environment.

Obsolete pesticides and application of colonizing plant species for remediation of contaminated soil in Kazakhstan

In Kazakhstan, there is a problem of finding ways to clean local sites contaminated with pesticides. In particular, such sites are the deserted and destroyed storehouses where these pesticides were stored; existing storehouses do not fulfill sanitary standards. Phytoremediation is one potential method for reducing risk from these pesticides. Genetic heterogeneity of populations of wild and weedy species growing on pesticide-contaminated soil provides a source of plant species tolerant to these conditions. These plant species may be useful for phytoremediation applications. In 2008-2009 and 2011, we surveyed substances stored in 80 former pesticide storehouses in Kazakhstan (Almaty oblast) to demonstrate an inventory process needed to understand the obsolete pesticide problem throughout the country, and observed a total of 354.7t of obsolete pesticides. At the sites, we have found organochlorine pesticides residues in soil including metabolites of dichlorodiphenyltrichloroethane and isomers of hexachlorocyclohexane. Twenty-four of the storehouse sites showed pesticides concentrations in soil higher than maximum allowable concentration which is equal to 100μgkg(-1) in Kazakhstan. Seventeen pesticide-tolerant wild plant species were selected from colonizing plants that grew into/near the former storehouse's pesticides. The results have shown that colonizing plant annual and biannual species growing on soils polluted by pesticides possess ability to accumulate organochlorine pesticide residues and reduce pesticide concentrations in soil. Organochlorine pesticides taken up by the plants are distributed unevenly in different plant tissues. The main organ of organochlorine pesticide accumulation is the root system. The accumulation rate of organochlorine pesticides was found to be a specific characteristic of plant species and dependent on the degree of soil contamination. This information can be used for technology development of phytoremediation of pesticide-contaminated soils.

American Dippers Indicate Contaminant Biotransport by Pacific Salmon

Migrating salmon can increase productivity in Pacific Northwestern streams and lakes through the deposition of nutrients from their decomposing carcasses after spawning. Several studies also report simultaneous biotransport of persistent organic pollutants that have contaminated lake food webs, although no similar effect has been shown conclusively in rivers. We tested the prediction that salmon enhance contaminants in river food webs using the American dipper (Cinclus mexicanus), an aquatic songbird and a recognized indicator of stream quality. Over 3 years, we analyzed 29 dipper eggs and aquatic invertebrate samples from 14 different rivers in 10 catchments in southern British Columbia, Canada to assess whether variations in autumn spawning density of Pacific salmon were reflected in dipper egg contamination or stable carbon and nitrogen isotopes. δ(13)C isotope signatures, but not δ(15)N, in aquatic invertebrates and dipper eggs increased among catchments in proportion to the average density of spawning salmon. Concentrations of brominated flame retardants (PBDEs), dichlorodiphenyltrichloroethane metabolites (DDTs), and chlordane compounds were related in part to the δ(13)C measure of salmon density, but mercury, chlorobenzenes, and polychlorinated biphenyls (PCBs) were explained better by dipper trophic level. We conclude that spawning Pacific salmon result in the increased availability of salmon fry as dipper prey and salmon are a significant source of PBDEs, DDTs, and chlordanes to river ecosystems. However, contrary to lake studies, postspawn concentrations of legacy PCBs in river birds, even in salmon-rich rivers, were not significantly higher than would be expected from atmospheric deposition alone. We recommend using δ(13)C isotopes to trace salmon-derived lipids which may persist over winter particularly in rivers, and are potentially a better reflection of lipophilic contaminant transfer.

Tissue Concentration of Organochlorines, Organophosphate and Plasma Cortisol in Captured Fish of Polluted River Gomti at Jaunpur during Post-Monsoon Season

The objectives of the present investigation was to monitor the HCHs (isomers of hexachlorocyclohexane), DDTs (metabolites of dichlorodiphenyltrichloroethane), chlorpyrifos in tissue bioaccumulation and plasma levels of cortisol between the sampling sites of the unpolluted ponds of Gujartal, Jaunpur (reference site) and the polluted rivers the Gomti (Jaunpur) and the Ganga (Varanasi) as stress hormone of some edible catfishes during non-breeding season owing to industrialization. The insecticides were measured by the gas liquid chromatography (GLC) and plasma cortisol by Enzyme-Linked Immunosorbents Assay (ELISA). The results indicated that the presence of HCHs, DDTs and chlorpyrifos was much higher in the catfishes captured from the river Gomti than those of the river Ganga when compared to reference site. The plasma level of cortisol was low in the fishes captured from both the rivers. In conclusion, the fishes from polluted rivers showed high degree of contamination which caused stress and ultimately decreased the growth of edible fishes of riverine sources.

Organochlorine pesticides (HCHs and DDTs) in soils along the north coastal areas of the Bohai Sea, China

A systematic survey of organochlorine pesticides (OCPs) including hexachlorocyclohexane isomers (α-HCH, β-HCH, γ-HCH, δ-HCH and ΣHCH) and dichlorodiphenyltrichloroethane metabolites (p,p′-DDT, p,p′-DDE, o,p′-DDT, p,p′-DDD and ∑DDT) in soils along the north coastal areas of the Bohai Sea, China, has been lacking. In this study, 31 representative surface soil samples were collected along the north coastal and riverine areas of the Bohai Sea to characterise the potential for adverse effects of ∑HCH, ∑DDT and their individual isomers and transformation products. Concentrations of ΣHCH and ΣDDT in soils ranged from less than the limit of detection (<LOD) to 3.0 × 101 ng · g−1 dw (mean: 3.5 ng · g−1 dw) and<LOD to 2.6 × 102 ng · g−1 dw (mean: 1.7 × 101 ng · g−1 dw), respectively. Compared with studies of OCPs in soils from other locations, concentrations of HCHs and DDTs observed in this study were moderate. Concentrations of OCPs observed in soils were generally less than proposed reference values. HCH residues were a mixture of historical technical HCH and current lindane sources. The pattern of DDTs was consistent with historical releases of technical DDTs. Selected soil physicochemical properties did not explain the sorption and/or partitioning of HCHs or DDTs.

Natural Mixtures of Persistent Organic Pollutants (POP) Increase Weight Gain, Advance Puberty, and Induce Changes in Gene Expression Associated with Steroid Hormones and Obesity in Female Zebrafish

In the present study, developmental and reproductive effects of lifelong exposure to environmental relevant concentrations of two natural mixtures of persistent organic pollutants (POP) were investigated using classical and molecular methods in a controlled zebrafish model. The mixtures used were extracted from burbot ( Lota lota ) liver originating from freshwater systems in Norway: one mixture with high levels and one mixture with background levels of polybrominated diphenyl ethers (PBDE), polychlorinated biphenyls (PCB), and dichlorodiphenyltrichloroethane metabolites (DDT). The concentration of POP measured in the zebrafish ranged from levels detected in wild fish from Lake Mjøsa to concentrations reported in human and wildlife populations, indicating that the experimental fish were exposed to concentrations comparable with wild fish. Phenotypic effects observed in both exposure groups included earlier onset of puberty, increased male/female sex ratio, and differences in body weight at 5 mo of age. Interestingly, genome-wide transcription profiling showed changes in regulation of genes involved in endocrine signaling and growth. The transcriptomics changes include key regulator genes for steroid hormone functions ( ncoa3 ), and growth (c/ebp, ncoa3 ). The effects observed in the experimental zebrafish model raise the question whether chemical pollution represents a risk to reproductive health of wild fish inhabitating the freshwater system.

Pesticide residues and reproductive dysfunction in different vertebrates from north India

Organochlorines (isomers of hexachlorocyclohexane – HCHs and metabolites of dichlorodiphenyltrichloroethane – DDTs, aldrin and endosulfan) and organophosphate (chlorpyrifos) insecticide residues were investigated by gas liquid chromatography in the blood of fish, chick, goat and man. The plasma levels of testosterone (T) and estradiol-17β (E2) was measured by radioimmunoassay in the catfish Rita rita captured from unpolluted reference site and polluted river Gomti during prespawning phase. Results indicated that in R. rita the ΣDDT, ΣHCH, endosulfan, aldrin, chlorpyrifos in blood levels were in preferential order (ΣDDT > ΣHCH > endosulfan > aldrin > chlorpyrifos) of their bioaccumulation. The blood levels of ΣHCH and ΣDDT also showed high levels in chick, goat and man, and preferential order of bioaccumulation was goat > chick > man > fish. The ΣDDT also showed preferential order (man > chick > goat > fish) of bioaccumulation. Among the different tissues of fish (blood, liver, brain and ovary) the ΣDDT was very high as compared to ΣHCH as well as the rest of tissues which was very selective bioconcentration in different tissues of fish during prespawning phase. The gonado-somatic index, T and E2 declined in the catfish captured from polluted river when compared with the catfish captured from reference site affecting reproductive physiology. Our results indicated that increase of insecticides in blood level in vertebrates causes reproductive dysfunction and suggested that for human beings food like fish, chick and goat containing beyond permissible limit of insecticides must be avoided.

Effects of p,p′ -DDE exposure on gonadal development and gene expression in Japanese medaka (Oryzias latipes)

Although 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p'-DDE), the major and most persistent metabolite of dichlorodiphenyltrichloroethane (DDT), was continually detected in wild fishes that showed abnormal gonad development such as intersex, little is known about the impact of p,p'-DDE exposure on gonad development in fishes. To survey the effects of p,p'-DDE on gonadal development and gene expressions, male juvenile (20-d post hatch) Japanese medaka (Oryzias latipes) was exposed to 1, 5, 20, and 100 microg/L p,p'-DDE for two months. Increased hepatosomatic index (HSI) and decreased gonadosomatic index (GSI) were found in the p,p'-DDE-treated groups. Intersex was found in 100 microg/L p,p'-DDE exposure group, as well as 100 ng/L 17alpha-ethynylestradiol (EE2) group. By quantitative real-time RT-PCR, it was found that gene expressions of vitellogenins (VTG-1, VTG-2), choriogenins (CHG-H, CHG-L), and estrogen receptor alpha (ER-alpha) in the liver of the fish were significantly up-regulated byp,p'-DDE exposure. VTG-1 and VTG-2 were recommended as the preferred biomarker for assessing anti-androgenic p,p'-DDE because they were the highest up-regulated among the genes and showed good dose-response relationship. The up-regulated ER-alpha suggested that a potential synergetic effect would occur when p,p'-DDE coexists with other ER-alpha-binding endocrine-disrupting chemicals (EDCs).

Investigation of hydrophobic contaminants in an urban slough system using passive sampling – insights from sampling rate calculations

Semipermeable membrane devices (SPMDs) were deployed in the Columbia Slough, near Portland, Oregon, on three separate occasions to measure the spatial and seasonal distribution of dissolved polycyclic aromatic hydrocarbons (PAHs) and organochlorine compounds (OCs) in the slough. Concentrations of PAHs and OCs in SPMDs showed spatial and seasonal differences among sites and indicated that unusually high flows in the spring of 2006 diluted the concentrations of many of the target contaminants. However, the same PAHs - pyrene, fluoranthene, and the alkylated homologues of phenanthrene, anthracene, and fluorene - and OCs - polychlorinated biphenyls, pentachloroanisole, chlorpyrifos, dieldrin, and the metabolites of dichlorodiphenyltrichloroethane (DDT) - predominated throughout the system during all three deployment periods. The data suggest that storm washoff may be a predominant source of PAHs in the slough but that OCs are ubiquitous, entering the slough by a variety of pathways. Comparison of SPMDs deployed on the stream bed with SPMDs deployed in the overlying water column suggests that even for the very hydrophobic compounds investigated, bed sediments may not be a predominant source in this system. Perdeuterated phenanthrene (phenanthrene-d (10)). spiked at a rate of 2 microg per SPMD, was shown to be a reliable performance reference compound (PRC) under the conditions of these deployments. Post-deployment concentrations of the PRC revealed differences in sampling conditions among sites and between seasons, but indicate that for SPMDs deployed throughout the main slough channel, differences in sampling rates were small enough to make site-to-site comparisons of SPMD concentrations straightforward.

Organochlorine pesticides and polychlorinated biphenyls in soil and water samples in the Northeastern part of São Paulo State, Brazil

Detailed analyses of persistent organic pollutants (POPs) such as organochlorine pesticides (OCPs), hexachlorocyclohexane (HCH) isomers (HCHs), dichlorodiphenyltrichloro ethane (DDT) and its metabolites (DDTs) and congeners of polychlorinated biphenyls (PCBs) in soil and surface water from the northeastern São Paulo, Brazil allowed the evaluation of the contamination status, distribution and possible pollution sources. The pesticides and PCBs demonstrated markedly different distributions, reflecting different agricultural, domestic and industrial usage in each region studied. The ranges of HCH, DDT, and PCBs concentrations in the soil samples were 0.05–0.92, 0.12–11.01, 0.02–0.25 ng g −1 dry wt, respectively, and in the surface water samples were 0.02–0.6, 0.02–0.58 and 0.02–0.5 ng l −1, respectively. Overall elevated levels of DDT and PCB were recorded in region 2, a site very close to melting, automotive batteries industries, and agricultural practice regions. High ratios of metabolites of DDT to DDT isomers revealed the recent use of DDT in this environment. The sources of contamination are closely related to human activities, such as domestic and industrial discharge, street runoff, agricultural pesticides and soil erosion, due to deforestation as well as atmospheric transport.

Exposure to PCBs and p,p ′-DDE and Human Sperm Chromatin Integrity

Persistent organochlorine pollutants (POPs) such as polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (p,p′-DDE), the major metabolite of dichlorodiphenyltrichloroethane (DDT), are stable lipophilic compounds widely found in the environment and in the general population. They can enter the food chain, and their negative impact on male reproduction is currently under active scrutiny. To explore the hypothesis that environmental exposure to these compounds is associated with altered sperm chromatin structure integrity in human sperm, we conducted a study of 176 Swedish fishermen (with low and high consumption of fatty fish, a very important exposure source of POPs). We determined serum levels of 2,2′,4,4′,5,5′-hexachlorobiphenyl (CB-153) and p,p′-DDE, and we used the sperm chromatin structure assay (SCSA) to assess sperm DNA/chromatin integrity. When CB-153 serum levels (individual dose range, 39–1,460 ng/g lipid) were categorized into equally sized quintiles, we found an association with the DNA fragmentation index (%DFI). A significantly lower %DFI was found in the lowest CB-153 quintile (< 113 ng/g lipid) compared with the other quintiles; there was a similar tendency, although not statistically significant, between %DFI and p,p′-DDE. These results suggest that POP exposure may have a slight negative impact on human sperm chromatin integrity.

Evaluation of the concentration of HCH, DDT, HCB, PCB and PAH in the sediments along the lower stretch of Hugli estuary, West Bengal, northeast India

Detailed analyses of persistent organic pollutants (POPs) such as hexachlorocyclohexane (HCH) isomers (HCHs), dichlorodiphenyltrichloro ethane (DDT) and its metabolites (DDTs), hexachlorobenzene (HCB) and congeners of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the coastal estuarine environment of West Bengal, northeast India allowed the evaluation of the contamination status, distribution and possible pollution sources. HCH, DDT, HCB, PCB and PAH were identified compounds in all the samples, whereas the concentrations of chlorinated pesticides (trans-eptachlorepoxide, dieldrin, endrin, metaoxychlor and mirex) were below the detection limits and were not of great concern. The pesticides did demonstrate markedly different distributions reflecting different agricultural and domestic usage in the region. The range of concentrations of HCH, HCB, DDT and PCBs in the sediments were 0.11–0.40, <0.05–0.98, 0.18–1.93 and 0.18–2.33 ng/g dry wt, respectively. Overall elevated levels of HCB, DDT and PCB were recorded at Babughat, a very closely located site of the metropolitan megacity Calcutta. Fluoranthene (flu) and pyrene (py), the dominant 4-ring PAHs, also showed an abrupt elevated concentrations at Babughat with values of 214 and 144 ng/g dry wt, respectively. Among the isomers and metabolites of HCH, DDT and PCB, α-HCH, pp′-DDT and PCB 101, PCB 118, PCB 153 and PCB 138 were found to be dominant. High ratios of metabolites of DDT to ΣDDTs reveal recent use of DDT in this coastal environment. Fluoranthene, pyrene, 1,2-benzo(a)anthracene and chrysene formed the dominant congeners out of 19 identified PAHs. The sources of contamination are closely related to human activities such as domestic and industrial discharge, automobile exhausts, street runoff, slum sewage, agricultural chemicals and soil erosion due to deforestation as well as atmospheric transport. This study is compared to other coastal and estuarine environments in India and abroad. The baseline data can be used for regular ecological monitoring, considering the industrial and agricultural growth around this important estuarine ecosystem.

Loss of capacity to elevate plasma cortisol in rainbow trout (Oncorhynchus mykiss) treated with a single injection of o,p′‐dichlorodiphenyldichloroethane

The organochlorine o,p'- dichlorodiphenyldichloroethane (o,p'-DDD) is a metabolite of dichlorodiphenyltrichloroethane (DDT), known for its adrenolytic actions in birds and mammals. The effects of o,p'-DDD on the cortisol stress response were investigated in rainbow trout, Oncorhynchus mykiss, in a dose-response study in vivo. A dose-dependent decrease in plasma cortisol levels was observed on days 7 and 14 after a single i.p. injection of o,p'-DDD. Treatment with o,p'-DDD had no effect on weight gain, hematocrit, and gonado- or hepatosomatic index but decreased liver glycogen reserves. The results indicate that o,p'-DDD is an adrenotoxic compound in rainbow trout and that its effects can be detected even 14 d postinjection.

Levels of certain metals, organochlorine pesticides and dioxins in cord blood, maternal blood, human milk and some commonly used nutrients in the surroundings of the Aral Sea (Karakalpakstan, Republic of Uzbekistan)

Since the 1960s a massive decline in the volume of the Aral Sea has occurred as a result of the diversion of the supplying rivers to cotton irrigation schemes. The contaminated sediment of the former seabed has been disseminated over the surrounding area by strong winds. This deterioration of the ecosystem has created a hazardous situation for the health of approximately 3.5 million people. This pilot study was undertaken to assist Karakalpak health workers in investigating the degree of exposure to metals, persistent organochlorine pesticides (OCPs) and dioxins during the most vulnerable prenatal and postnatal period and to provide guidelines for future research. All subjects came from areas located within 200 km of the southern border of the Aral Sea. Blood was obtained from 18 pregnant women and 28 newborns (cord blood) to determine the levels of metals, lead, cadmium, zinc and selenium and the OCPs alpha-, beta- and gamma-hexachlorocyclohexane (HCH; lindane is the product name of gamma-hexachlorocyclohexane), hexachlorobenzene (HCB), and isomers and metabolites of dichlorodiphenyltrichloroethane (DDT), i.e. op-DDT, pp-DDT, pp-DDE and pp-TDE. Levels of metals were also determined in blood from 28 non-pregnant women. In addition, levels of 17 dioxins were determined in 41 human milk samples and 1batch of formula. Information about possible dietary sources of the fat-soluble OCPs and dioxins was obtained from a pooled sample of butter and from seven cottonseed oil samples. A mass-selective detector coupled to a gas chromatograph equipped with a large volume injector was used to analyse the selected OCPs, whereas the dioxins were determined by gas chromatography with high-resolution mass spectrometry. The levels of metals in cord and maternal blood were consistent with concentrations observed in European countries. Only three women (7%) had lead levels greater than 100 ppb. The most notable pollutants in maternal and cord blood were the OCPs, notably HCB, beta-HCH, pp-DDE and the most toxic dioxin, 2,3,7,8-TCDD, when calculated as TEQs. A similar pattern was observed in human milk: beta-HCH and pp-DDE levels of more than 1,000 ng g(-1) fat were found in 68 and 43% of the subjects, respectively. Levels of 2,3,7,8-TCDD were six times higher than those observed in Western Europe. Traces of pp-DDE were detected in the batch of formula milk. Contaminated animal fat, but not cottonseed oil, is the most likely dietary source of OCPs and dioxins. Further epidemiological research is needed to elucidate the health implications of these pollutants on perinatal and maternal health, including lactation. More importantly, an investigation should be initiated to identify the emission sources of persistent organic pollutants in Karakalpakstan and adjacent regions.

Relation of Lake Ontario Fish Consumption, Lifetime Lactation, and Parity to Breast Milk Polychlorobiphenyl and Pesticide Concentrations

Lactating female members and spouses of male members of the New York State Angler Cohort who agreed to provide breast milk samples were the subjects of this study. Questionnaires were provided to participants focusing on Lake Ontario fish consumption, reproductive history, and lactation history. Milk samples were analyzed for 77 polychlorinated biphenyls (PCB) congeners, 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (DDE), a metabolite of dichlorodiphenyltrichloroethane (DDT), hexachlorobenzene (HCB), and 1,1a,2,2,3,3a, 4,5,5,5a,5b,6-dodecachlorooctahydro-1,3,4-methano-1H-cyclobuta[cd]pentalene (Mirex). The percentage of samples with quantifiable levels, above the limit of detection (LOD), varied among the individual congeners from 10 to 100%. Nine PCB congeners (designated by their IUPAC No.) and DDE were found in all of the 100 samples analyzed. These include the following, in decreasing order of concentration: DDE>153>138>180>118>187>188>177>200. Total PCB concentrations were estimated by taking the sum of the concentrations of all PCB congeners (up to 77 congeners) above their respective LOD in a given sample. PCB concentrations increased with increasing concentration of milk lipid. Lipid adjusted PCB concentrations increased as a function of maternal age. PCB congener profiles in milk favored the higher chlorinated congeners, with the four highest congeners having 5 to 7 chlorine atoms. Fish eaters had a significantly higher level of several major PCB congeners with congeners 153 and 138 being 1.36 and 1.34 times higher, respectively. PCB and DDE concentrations, expressed on a lipid basis, varied inversely with parity. The total number of months of lifetime lactation varied inversely with the total PCB concentration in breast milk. A similar relationship was evident for DDE. These data are of use for risk assessment in estimating the relative exposure to these environmental contaminants in breast fed infants whose mothers consumed contaminated Lake Ontario fish.

Predictors of Plasma Concentrations of DDE and PCBs in a Group of U.S. Women

We evaluated predictors of plasma concentrations of dichlorodiphenyldichloroethylene (DDE), a metabolite of dichlorodiphenyltrichloroethane (DDT), and polychlorinated biphenyls (PCBs) in a group of 240 women, controls from a breast cancer case-control study nested in the Nurses' Health Study. We considered personal attributes such as age, serum cholesterol, region of residence, adiposity, lactation, and dietary intake. DDE levels increased 0.17 ppb/year of age (p = 0.0003), and PCBs increased 0.08 ppb (p = 0.0001). DDE and PCBs increased 0.20 (p = 0.02) and 0.13 ppb (p = 0.001), respectively, per 10 mg/dl serum cholesterol. Women living in the western United States had higher levels of DDE (mean = 11.0 ppb; p = 0.003), and women in the Northeast and Midwest had higher levels of PCBs (mean = 5.6 ppb; p = 0.0002) as compared to women from other parts of the country (mean DDE = 6.3; mean PCBs = 4. 5 ppb). Levels of DDE could not be predicted from consumption of meat, fish, poultry, dairy products, vegetables, fruits, and grains. There was a positive association between fish consumption and PCB concentrations among women in the Northeast and Midwest. Using data from the cases in the nested case-control study to assess the predictive ability of the models, we confirmed that the most reliable predictors of DDE were age and serum cholesterol, and the most important predictors of PCBs were age, serum cholesterol, and residence in the Midwest or Northeast. The null results for the majority of the food variables suggest that specific dietary factors, other than fish, are not currently a substantial contributor to human exposure to DDE and PCBs.