Combining data sets of organochlorines (OCs) in human plasma for the Russian Arctic

As part of AMAP's human circumpolar study of POPs, an international effort was initiated to extend coverage to communities across the Russian Arctic. Two additional laboratories were invited to join the analytical component of this effort, resulting in four participating analytical centres. Although quality assurance measures were put in place, and the level of performance of the laboratories was generally acceptable, deficiencies in the analytical protocols used were recognized subsequent to the collection and analyses of the plasma specimens. The current paper describes the criteria employed to critically appraise the four data bases and guide their integration into a single data set. Summary statistics are presented for plasma concentrations of major PCBs, p,p′-DDE, p,p′-DDT, β-HCH, and HCB for communities/regions across the arctic/subarctic Russian continent, and for one community located in the Aral Sea area of Uzbekistan (a control group). Highly exposed people were identified in the coastal communities of Chukotka, which appears mainly related to marine mammal intake, but recent pesticide use is also suspected. Other communities with intermediate levels of PCBs had relatively elevated β-HCH, p,p′-DDT and HCB concentrations and low DDE/DDT ratios (<10), suggesting recent pesticide use.     

Maternal levels of organochlorines in two communities in southern Vietnam

Some pesticides and PCBs continue to be reported as environmental problems in some areas of Vietnam. In 2005, a study among delivering women took place in two communities in south-central Vietnam (Khanh Hoa Province), namely the coastal city of Nha Trang and the rural district of Dien Khanh located about 10 km inland. The main findings in plasma (n = 189) were relatively high mean concentrations of p,p′-DDE (12.2 µg/l in Nha Trang and 11.4 µg/l in Dien Khanh) and p,p′-DDT (1.2 µg/l in Nha Trang and 1.1 µg/l in Dien Khanh) with no significant community differences. The ratio of p,p′-DDE/p,p′-DDT (11.5 in Nha Trang/12.7 in Dien Khanh) suggests, as in other Vietnamese OCs studies, a relatively recent use of this pesticide. Mean concentrations of PCB 153 (0.15 µg/l in Nha Trang and 0.10 µg/l in Dien Khanh) and other congeners were low in both communities. Age and parity (all compounds), as well as community of residence for PCB 153, were the most important predictors of plasma OCs concentrations.     

Levels of chlorinated pesticides and polychlorinated biphenyls in Norwegian breast milk (2002-2006), and factors that may predict the level of contamination

In the present study, polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in 423 breast milk samples from women living in Norway. Various predictors for the contaminant levels were also investigated. The samples were collected in six counties, representing South, Central and North Norway in 2002-2006. Initial results showed significantly lower levels of OCPs in breast milk from ethnic Norwegians (N = 377) compared to ethnic non-Norwegians (N = 46). Median concentrations (range) of PCBs, p,p′-DDE, HCB, β-HCH and oxychlordane in breast milk of the Norwegian women, all parities included, were 103 (34-450), 41 (5.4-492), 11 (3.6-24), 4.7 (0.9-37) and 2.8 (0.5-16) ng/g lipid weight, respectively. Results indicated that sum of 18 PCBs, p,p′-DDE and β-HCH are good predictors for monitoring of PCB, DDT and HCH levels in Norwegian breast milk. Multivariable linear regression analyses showed that age was strongly associated with increasing OC levels (P < 0.001), whereas parity was associated with decreasing OC levels (P < 0.001). Smoking was associated with higher levels of PCBs, p,p′-DDE and β-HCH. The models explained from 17 to 35% of the variance. Median levels of OCs in the present Norwegian primparaes seemed to be 29-62% lower than corresponding results found in a Norwegian study from 2000-2002.     

Accumulation of polychlorinated biphenyls and organochlorine pesticide in pet cats and dogs: Assessment of toxicological status

PCB and DDT concentrations were determined in the adipose tissue of cats and dogs from Southern Italy. In cats p,p′-DDE was the most abundant DDT component (95.0%), while in dogs these compounds were absent, except in two specimens. PCB concentrations were higher in cats (199.02 ng g^− 1 lipid weight) than in dogs (41.61 ng g^− 1 lipid weight). Also there were inter-specific differences in the contribution of the different congeners to PCBs, although PCB 138, PCB 153 and PCB 180 were the most representative congeners in both species. Animals from one location, Taranto City, had significantly elevated concentrations of dioxin-like PCBs compared to the other locations. Consequently the estimated mean 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) of coplanar PCBs were higher in these animals (cats: 0.65 pg g^− 1 lipid weight; dogs 0.29 pg g^− 1 lipid weight) than in the other ones (cats: 0.12 pg g^− 1 lipid weight; dogs: 0.001 pg g^− 1 lipid weight).     

Organochlorines and heavy metals in wild caught food as a potential human health risk to the indigenous Māori population of South Canterbury, New Zealand

Increasing concentrations of anthropogenic contaminants in wild kai (food) of cultural, recreational and economic importance to the indigenous Māori of New Zealand is a potential human health risk. Contaminants that are known to bioaccumulate through the food chain (e.g., organochlorine pesticides (OCPs), PCBs and selected heavy metals) were analysed in important kai species including eel (Anguilla sp.), brown trout (Salmo trutta), black flounder (Rhombosolea retiaria) and watercress (Nasturtium officinale) from important harvesting sites in the region of South Canterbury. Eels contained relatively high wet weight concentrations of p,p′-DDE (8.6-287 ng/g), PCBs (³²Σ_PCB; 0.53-58.3 ng/g), dieldrin (< 0.05-16.3 ng/g) and Σchlordanes (0.03-10.6 ng/g). Trout and flounder contained lower concentrations of organochlorines than eels, with p,p′-DDE wet weight concentrations ranging from 2.2 to 18.5 ng/g for trout and 6.4 to 27.8 ng/g for flounder. Total arsenic wet weight concentrations were below detection limits for eels but ranged from 0.27 to 0.89 μg/g for trout and 0.12 to 0.56 μg/g for flounder. Mercury concentrations ranged from 0.02 to 0.56 μg/g, 0.11 to 0.50 μg/g and 0.04 to 0.10 μg/g (ww) for eel, trout and flounder respectively. Lifetime excess cancer risk was calculated through established risk assessment procedures, highlighting dieldrin, ΣPCBs and p,p′-DDE in eels and arsenic in trout and flounder as primary contaminants of concern. A second non-cancer chronic health risk assessment indicated that mercury and PCBs were a potential concern in eels and mercury in trout. A cumulative lifetime cancer risk assessment showed potential health risk for consumption of some species, even at low consumption rates and provided the basis for establishing recommended dietary consumption limits for harvest sites within the study region.     

Concentrations and determinants of organochlorine levels among pregnant women in Eastern Spain

Persistent organic pollutants (POPs) comprise a large variety of toxic substances with ample distribution. While exposure to these toxins occurs mainly through diet, maternal POP levels may be influenced by certain sociodemographic, environmental, or lifestyle factors. This is important given that these substances may have adverse effects on fetal development. The aim of this study is to examine the sociodemographic, environmental, lifestyle, and dietary determinants of the levels of hexachlorobenzene (HCB), b-hexachlorocyclohexane (b-HCH), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (4,4′-DDT), 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (4,4′-DDE), and polychlorinated biphenyls (PCB congeners 118, 138, 153, 180) measured in the blood of pregnant women participating in a mother-child cohort study conducted in Valencia (Spain).The study population consisted of 541 pregnant women who formed part of the INMA (Childhood and the Environment) cohort (2004-2006). POP levels were determined in blood taken during the 12th week of pregnancy with the aid of gas chromatography with electron capture detection. Sociodemographic, environmental, and dietary information was obtained from a questionnaire. Multivariate Tobit regression models were constructed in order to assess the association between POP levels and selected covariates.The results showed that all the women had detectable levels of at least one of these compounds while in 43% of the subjects, all eight compounds were detected. The compounds found in the greatest number of women were 4,4′-DDE (100%) and PCBs 153 and 180 (95%). The most important determinants of high POP levels were the mother's age, country of origin, increased body mass index, and number of weeks of breastfeeding after previous pregnancies. With regard to diet, 4,4′-DDT and 4,4′-DDE levels increased with the intake of meat, fruit, and cereal. PCB 153 levels increased with the intake of seafood. The levels of HCB, b-HCH, 4,4′-DDT, and 4,4′-DDE observed in this study were slightly higher than in other studies, whereas the PCB levels were similar.     

Organochlorines and mercury in livers of great cormorants (Phalacrocorax carbo sinensis) wintering in northeastern Mediterranean wetlands in relation to area, bird age, and gender

Wild birds are exposed to pollutants in their habitats. Top consumers of aquatic environments such as the fish-eating great cormorant (Phalacrocorax carbo sinensis) are especially affected due to the bioaccumulation of toxic substances in their tissues. This study analysed the livers of 80 great cormorants from Greece to estimate the concentration of organochlorines and mercury and to examine their possible toxic effects and origin. The results showed that mercury (geometric mean 8089 ng g⁻¹ dw), p,p′-DDE (2628 ng g⁻¹ dw), ∑ HCHs (47 ng g⁻¹ dw) and HCB (116 ng g⁻¹ dw) concentrations can be considered high compared with those found in great cormorant livers elsewhere except in highly polluted areas, whereas ∑ PCBs occurred in relatively low concentrations (1091 ng g⁻¹ dw). β-HCH was the dominant HCH isomer. Pollutant levels were generally unrelated to area, age and gender. However, p,p′-DDE and p,p′-DDD showed intersite differences, whilst the proportion of PCBs with 8 chlorine atoms were significantly higher in adult than 1st year great cormorants. Pollution did not reflect local patterns but rather these along the Baltic and Black Seas, whilst differences in p,p′-DDE concentration and ∑ DDTs/∑PCBs ratios between Evros, Axios or Amvrakikos, found on common migration route, suggested different bird origins. Most birds had toxic mercury concentrations; 83.7% above 4000 ng g⁻¹ dw and 16% above 17,000 ng g⁻¹ dw. Other pollutant levels were too low to have adverse effects.     

Altered developmental timing in early life stages of Antarctic krill (Euphausia superba) exposed to p,p'-DDE

Persistent organic pollutants (POPs) are persistent, toxic and bioaccumulative anthropogenic organic chemicals, capable of undergoing long range environmental transport to remote areas including the Antarctic. p,p′-dichlorodiphenyl dichloroethylene (p,p′-DDE) has been identified as a dominant POP accumulating in Antarctic krill (Euphausia superba), which is a key Southern Ocean species. This study examined the developmental toxicity of p,p′-DDE via aqueous exposure to Antarctic krill larvae. p,p′-DDE exposure was found to stimulate developmental timing in the first three larval stages of Antarctic krill, while extended monitoring of larvae after a five day exposure period had ended, revealed delayed inhibitory responses during development to the fourth larval stage. Stimulatory responses were observed from the lowest p,p′-DDE body residue tested of 10.1 ± 3.0 μmol/kg (3.2 ± 0.95 mg/kg) preserved wet weight, which is comparable to findings for temperate species and an order of magnitude lower than the exposure level found to cause sublethal behavioural effects in Antarctic krill. The delayed responses included increased mortality, which had doubled in the highest p,p′-DDE treatment (95 ± 8.9% mortality at 20 μg/L p,p′-DDE) compared to the solvent control (44 ± 11% mortality) 2 weeks after end of exposure. Development of surviving metanauplius larvae to calyptopis 1 larvae was delayed by 2 days in p,p′-DDE exposed larvae compared with untreated larvae. Finally, the developmental success of surviving p,p′-DDE exposed larvae was reduced by 50 to 75% compared to the solvent control (100% developmental success). The lowest observed effect concentration for all delayed effects was 1 μg/L, the lowest exposure concentration tested. These findings demonstrate the importance of delayed and indirect effects of toxicant exposure. Further, the findings of this study are important for environmental risk assessment of POPs in the Southern Ocean ecosystem and strongly highlight the significance of developmental endpoints for ecotoxicological testing.     

Particle deposition fluxes of BDE-209, PAHs, DDTs and chlordane in the Pearl River Delta, South China

Year-round bulk air deposition samples were collected at 15 sites in the Pearl River Delta (PRD) on a bimonthly basis from Dec 2003 to Nov 2004, and the particle-phase deposition of BDE-209, PAHs, DDTs and chlordane was measured. The annual deposition fluxes of BDE-209, total PAHs (15 compounds), total DDT (sum of p,p′-DDE, p,p′-DDD, p,p′-DDT, and o,p′-DDT ), and chlordane (sum of trans-chlordane and cis-chlordane) varied from 32.6 to 1970 μg m^− 2 yr^− 1, 22 to 290 μg m^− 2 yr^− 1, 0.8 to 11 μg m^− 2 yr^− 1, and 0.25 to 1.9 μg m^− 2 yr^− 1, respectively. Spatial variations were higher in the centre of the PRD and lower at the coastal sites for all compounds. The seasonal variations of deposition were found to be compound-dependent, influenced by a number of factors, such as the timing of source input, temperature, and precipitation etc. In particular, source input time affected the deposition fluxes of BDE-209 and high-weight PAHs, while temperature-dependent gas-particle partitioning was a key factor for DDT and light-weight PAH deposition. During the whole sampling period, the atmospheric deposition of BDE-209, ΣPAHs, ΣDDTs, and chlordane onto Hong Kong reached about 93, 86, 2.1 and 2.1 kg yr^− 1, respectively, and onto the PRD reached about 13,400, 2950, 82, and 63 kg yr^− 1. By comparing the calculated total air deposition with the burden in the soils, the half residual time of BDE-209 in soils was estimated to be 3 years.     

Concentration of selected persistent organic pollutants in blood from delivering women in South Africa

Environmental exposure to persistent organic pollutants (POPs) may cause detrimental health effects in the population with the developing foetus and infants being at highest risk. This paper reports on the findings of the pilot study that took place in seven geographical regions of South Africa, 96 pregnant women admitted for delivery participated in the study. The following selected POPs were analysed in maternal plasma: 15 polychlorinated biphenyls (PCBs) congeners (IUPAC No. 28, 52, 99, 101, 105, 118, 138, 149, 153, 156, 170, 180, 183, 187, 194); six DDT metabolites (dichlordiphenyltrichloroethane p,p'-DDT and o,p'-DDT; diphenyldichloroethylene p,p'-DDE and o,p'-DDE, dichlorophenylethane p,p'-DDD o,p'-DDD) and other pesticides such as hexachlorocyclohexanes (α-HCH, β-HCH, γ-HCH), hexachlorobenzene (HCB), heptachlor, chlordanes (t-CD and c-CD), nanochlors (t-NC and c-NC) and mirex.The overall results showed large regional differences with the rural site having the lowest levels for all measured contaminants. The levels of PCB congeners were found to be low in all samples and across all sites. DDT metabolites were detected in most participants of this study and large regional differences were evident. Two malaria endemic sites, where indoor residual spraying (IRS) with DDT takes place to control malaria vector, were included in the study. The highest levels of DDTs were measured in the coastal malaria site (Indian Ocean) with geometric means of 5177 ng/g lipid and 1797 ng/g lipid for p,p'-DDE and p,p'-DDT, and 1966 ng/g lipid and 726 ng/g lipid for p,p'-DDE and p,p'-DDT in inland malaria site. γ-HCH was found to be elevated overall, except for the urban community; the highest levels were measured in the inland and coastal malaria sites. p,p'-DDT and γ-HCH were however not correlated, indicating different sources. The high DDT levels in the malaria spraying regions as well as the elevated γ-HCH levels are of concern and call for extended monitoring of women and children in selected regions.     

Relationship between serum concentrations of polychlorinated biphenyls and organochlorine pesticides and dietary habits of pregnant women in Shanghai

The use of most polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) has been restricted in China; however, their use remains a concern because of their adverse effects on human health, especially on fetuses and infants. To date, there is no data regarding the exposure levels of pregnant women to PCBs and OCPs in Shanghai. In order to evaluate PCB and OCP exposure levels and the contribution of dietary habits to these levels, we determined the concentrations of 8 PCBs and 14 OCPs in the umbilical cord blood serum of healthy pregnant women in Shanghai. Dietary habits of the pregnant women were obtained from a self-administered questionnaire. Results showed that p, p′-DDE, HCB and β-HCH were the major pollutants present in the serum samples; PCBs were detected in a few samples at low concentrations. Age, weight and body mass index before delivery were positively associated with serum levels of p, p′-DDE and β-HCH. Women and their husbands who had higher education levels, higher income levels, tended to have higher levels of p, p′-DDE and β-HCH. Spearman correlation analysis results suggested that consumption of foods such as milk, eggs, meat, fish, and shrimp may contribute to higher serum levels of p, p′-DDE and β-HCH. Furthermore, multiple linear regression analyses indicated that the age and educational levels of the pregnant women and their intake of fried/flamed food and shellfish were positively associated with β-HCH levels, and that the age and educational levels of the pregnant women and their intake of parity, beef, pork, mutton, and shrimp were positively associated with p, p′-DDE levels. This is the first study to investigate the exposure levels of pregnant women to PCBs and OCPs in Shanghai, and it should provide useful information for future related research.     

The role of diet on long-term concentration and pattern trends of brominated and chlorinated contaminants in western Hudson Bay polar bears, 1991-2007

Adipose tissue was sampled from the western Hudson Bay (WHB) subpopulation of polar bears at intervals from 1991 to 2007 to examine temporal trends of PCB and OCP levels both on an individual and sum-(∑-)contaminant basis. We also determined levels and temporal trends of emerging polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), polybrominated biphenyls (PBBs) and other current-use brominated flame retardants. Over the 17-year period, ∑ DDT (and p,p′-DDE, p,p′-DDD, p,p′-DDT) decreased (−8.4%/year); α-hexachlorocyclohexane (α-HCH) decreased (−11%/year); β-HCH increased (+ 8.3%/year); and ∑ PCB and ∑ chlordane (CHL), both contaminants at highest concentrations in all years (> 1 ppm), showed no distinct trends even when compared to previous data for this subpopulation dating back to 1968. Some of the less persistent PCB congeners decreased significantly (−1.6%/year to −6.3%/year), whereas CB153 levels tended to increase (+ 3.3%/year). Parent CHLs (c-nonachlor, t-nonachlor) declined, whereas non-monotonic trends were detected for metabolites (heptachlor epoxide, oxychlordane). ∑ chlorobenzene, octachlorostyrene, ∑ mirex, ∑ MeSO₂-PCB and dieldrin did not significantly change. Increasing ∑ PBDE levels (+ 13%/year) matched increases in the four consistently detected congeners, BDE47, BDE99, BDE100 and BDE153. Although no trend was observed, total-(α)-HBCD was only detected post-2000. Levels of the highest concentration brominated contaminant, BB153, showed no temporal change. As long-term ecosystem changes affecting contaminant levels may also affect contaminant patterns, we examined the influence of year (i.e., aging or “weathering” of the contaminant pattern), dietary tracers (carbon stable isotope ratios, fatty acid patterns) and biological (age/sex) group on congener/metabolite profiles. Patterns of PCBs, CHLs and PBDEs were correlated with dietary tracers and biological group, but only PCB and CHL patterns were correlated with year. DDT patterns were not associated with any explanatory variables, possibly related to local DDT sources. Contaminant pattern trends may be useful in distinguishing the possible role of ecological/diet changes on contaminant burdens from expected dynamics due to atmospheric sources and weathering.     

Composition, distribution, and potential toxicity of organochlorine mixtures in bed sediments of streams

Mixtures of organochlorine compounds have the potential for additive or interactive toxicity to organisms exposed in the stream. This study uses a variety of methods to identify mixtures and a modified concentration-addition approach to estimate their potential toxicity at 845 stream sites across the United States sampled between 1992 and 2001 for organochlorine pesticides and polychlorinated biphenyls (PCBs) in bed sediment. Principal-component (PC) analysis identified five PCs that account for 77% of the total variance in 14 organochlorine compounds in the original dataset. The five PCs represent: (1) chlordane-related compounds and dieldrin; (2) p,p′-DDT and its degradates; (3) o,p′-DDT and its degradates; (4) the pesticide degradates oxychlordane and heptachlor epoxide; and (5) PCBs. The PC analysis grouped compounds that have similar chemical structure (such as parent compound and degradate), common origin (in the same technical pesticide mixture), and(or) similar relation of concentrations to land use. For example, the highest concentrations of chlordane compounds and dieldrin occurred at urban sites, reflecting past use of parent pesticides for termite control. Two approaches to characterizing mixtures—PC-based mixtures and unique mixtures—were applied to all 299 samples with a detection of two or more organochlorine compounds. PC-based mixtures are defined by the presence (in the sample) of one or more compounds associated with that PC. Unique mixtures are defined as a specific combination of two or more compounds detected in a sample, regardless of how many other compounds were also detected in that sample. The simplest PC-based mixtures (containing compounds from 1 or 2 PCs) commonly occurred in a variety of land use settings. Complex mixtures (containing compounds from 3 or more PCs) were most common in samples from urban and mixed/urban sites, especially in the Northeast, reflecting high concentrations of multiple chlordane, dieldrin, DDT-related compounds, and(or) PCBs. The most commonly occurring unique mixture (p,p′-DDE, p,p′-DDD) occurred in both simple and complex PC-based mixtures, and at both urban and agricultural sites. Mean Probable Effect Concentration Quotients (PEC-Q) values, which estimate the potential toxicity of organochlorine contaminant mixtures, were highest for complex mixtures. Mean PEC-Q values were highest for urban sites in the Northeast, followed by mixed/urban sites in the Northeast and agricultural sites in cotton growing areas. These results demonstrate that the PEC-Q approach can be used in combination with PC-based and unique mixture analyses to relate potential aquatic toxicity of contaminant mixtures to mixture complexity, land use, and other surrogates for contaminant sources.     

Probabilistic ecological risk assessment of DDTs in the Bohai Bay based on a food web bioaccumulation model

The fugacity-based food web model was developed to simulate the bioaccumulation of dichloro-diphenyl-trichloroethanes (DDTs) in the aquatic ecosystem in the Bohai Bay. The internal exposure levels (IELs) of DDTs in various organism categories were calculated. Monte Carlo-based uncertainty analysis was performed to get the of IEL distributions of DDTs in organisms. Probabilistic ecological risk assessment (ERA) was performed based on IEL distributions and internal species sensitivity distributions (SSDs). The results show that fugacities and bioaccumulation factors (BAFs) generally increased with increasing trophic level in the food web. Octanol-water partition coefficient (K_ow), DDT levels in water and the lipid contents had the greatest influences on IELs in the organism bodies. The ecological risks of DDTs were relatively high. The risk order was p,p′-DDT > p,p′-DDE > p,p′-DDD. At an internal hazard quotient (HQ_int) criterion of 1/5, the risk probabilities were 0.10 (0.055-0.17), 0.079 (0.045-0.13) and 0.053 (0.028-0.092) for p,p′-DDT, p,p′-DDE and p,p′-DDD, respectively. The results from ERA based on the internal exposure approximated those based on external exposure. The food web model is a feasible method to predict the extent of bioaccumulation and IELs of hydrophobic organic pollutants in organisms as a step to evaluate their risk posed on aquatic ecosystems.     

Organochlorine pesticides in colostrums in case of normal and preterm labor (IASI, Romania)

Assessment of organochlorine pesticides (OCPs) in human body is important for human health because they have weak estrogenic or antiestrogenic effects and are considered endocrine disrupters. We used colostrum of women as indicator for levels of OCPs in human body for mothers with normal and preterm labor from eastern part of Romania. Sixty- three samples of colostrum were extracted by solid-phase extraction. Analyses were carried out using gas chromatography coupled to mass spectrometry (GC-MS). OCPs have been detected in all samples, with p,p’-dichlorodiphenyldichloroethylene (p,p’-DDE) and γ-hexachlorocyclohexane (γ-HCH) being at the highest concentrations. Of the organochlorines measured in clostrum samples from women in preterm labor, median levels of DDTs (470 ng/g) and HCHs (99 ng/g) were higher than for the same compounds from women in normal labor (median of DDTs = 268 ng/g and median of HCHs = 96 ng/g). Normal labor had higher median concentrations of HCB (19.5 ng/g) versus preterm labor (14 ng/g). Statistical data show high Spearman correlation coefficients between various OCPs. We found a good correlation between α-, γ-, β- and δ- HCH isomers (p < 0.001) for both normal and preterm labor. The most abundant target compound was p,p’-DDE (median value 96 ng/g, and 137 ng/g for mother with normal and preterm labor, respectively) in all colostrum samples. The estimated daily intakes of HCHs by infants exceeded corresponding Health Canada guidelines.     

Organochlorine residues in two seal species from Western Iceland

Harbour seals and grey seals from Faxaflói (Western Iceland) were analyzed for contamination with organochlorines (HCB, PCBs, p,p′-DDT, p,p′-DDE, chlordanes and the enantiomers of α-HCH). Although the values strongly varied, both harbour seals and grey seals on average showed comparable levels of PCBs, p,p′-DDT, p,p′-DDE and α-HCH, as well as chlordanes (ΣCD). Differences were measured in the HCB content of the seal species. The HCB/α-HCH ratio in harbour seals was <1 and in grey seals >1. The results from seals on Iceland were compared with data derived from seal samples of the Antarctic, the Arctic (Spitzbergen) and the North Sea (Germany) in order to give an insight into the global distribution of pollution with chlorinated organics.     

Prenatal exposure to organochlorine pesticides and TSH status in newborns from Southern Spain

Objective

To investigate the association between prenatal exposure to organochlorine pesticides (OCPs) and thyroid-stimulating hormone (TSH) levels in male newborns.

Methods

Exposure to 17 OCPs was analyzed in 220 placentas from a male birth cohort in Southern Spain, and TSH was measured in the umbilical cord blood. OCP concentrations were quantified by gas chromatography and mass spectrometry. Multivariate regression analysis was conducted to examine the association between pesticide exposure and neonatal TSH levels, adjusting for confounders.

Results

Newborn boys with higher exposure to endrin in placenta had higher odds of TSH cord blood levels ≥ 5 mU/L (80th percentile) (OR = 2.05; 95% CI = 1.01, 4.18; p = 0.05), whereas higher prenatal exposure to endosulfan-sulfate was associated with lower odds of TSH ≥ 5 mU/L (OR = 0.36; 95% CI = 0.17, 0.77; p = 0.008). A marginally significant negative association was found between TSH and hexachlorobenzene levels (β = − 0.15; 95% CI = − 0.31, 0.02; p = 0.09), and exposure to p,p′-DDE showed a marginally-significant higher odds of TSH ≥ 5 mU/L (OR = 1.32; 95% CI = 0.95, 1.83; p = 0.09). No association was found between TSH and the remaining pesticides.

Conclusions

Early exposure to certain environmental chemicals with endocrine-disruption activity may interfere with neonatal thyroid hormone status; however, the pattern of interference is not yet clearly elucidated.     

DDT contamination from indoor residual spraying for malaria control

The insecticide DDT is still used in specific areas of South Africa for indoor residual spray (IRS) to control malaria vectors. Local residents could be exposed to residues of DDT through various pathways including indoor air, dust, soil, food and water. The aims of this study were to determine the levels of DDT contamination, as a result of IRS, in representative homesteads, and to evaluate the possible routes of human exposure. Two villages, exposed (DV) and reference (TV) were selected. Sampling was done two months after the IRS process was completed. Twelve homesteads were selected in DV and nine in TV. Human serum, indoor air, floor dust, outside soil, potable water, leafy vegetables, and chicken samples (muscle, fat and liver) were collected and analyzed for both the o,p′- and p,p′-isomers of DDT, DDD and DDE. DDT was detected in all the media analyzed indicating a combination of potential dietary and non-dietary pathways of uptake. DV had the most samples with detectable levels of DDT and its metabolites, and with the exception of chicken muscle samples, DV also had higher mean levels for all the components analyzed compared to TV. Seventy-nine percent of participants from DV had serum levels of DDT (mean ∑ DDT 7.3 µg g⁻¹ lipid). These residues constituted mainly of p,p′-DDD and p,p′-DDE. ∑ DDT levels were detected in all indoor air (mean ∑ DDT 3900.0 ng m^− 3) and floor dust (mean ∑ DDT 1200.0 µg m^− 2) samples. Levels were also detected in outside soil (mean ∑ DDT 25.0 µg kg^− 1) and potable water (mean ∑ DDT 2.0 µg L^− 1). Vegetable sample composition (mean ∑ DDT 43.0 µg kg^− 1) constituted mainly p,p′-DDT and p,p′-DDD. Chicken samples were highly contaminated with DDT (muscle mean ∑ DDT 700.0 µg kg^− 1, fat mean ∑ DDT 240,000.0 µg kg^− 1, liver mean ∑ DDT 1600.0 µg kg^− 1). The results of the current study raise concerns regarding the potential health effects in residents living in the immediate environment following DDT IRS.     

Exposure of young mothers and newborns to organochlorine pesticides (OCPs) in Guangzhou, China

Exposure of young mothers and newborns to organochlorine pesticides (OCPs) were assessed by measuring the levels of OCPs in human milk (HM) and maternal blood (MB) and umbilical cord blood (UCB) samples from Guangzou in China. 21 OCPs were analyzed using gas chromatography/mass spectrometry (GC/MS). The results showed that the median levels (ranges) of total HCHs (four HCH isomers) in HM, MB and UBC were 54.7 (5.7-159.3), 43.7 (1.9-386.6), and 20.2 (4.0-103.2) ng/g lipid, respectively; and the median concentration of total DDTs (DDT and its metabolites) were 2114.6 (329.1-6164.6), 1676.0(283.4-6167.7), and 1287.8(189.6-3296.0) ng/g lipid, respectively. On a lipid basis, the chemical concentrations were in the order HM > MB > UCB. Comparison with literature data showed that the levels of ∑DTTs and ∑HCHs in milk and maternal blood samples were within the range reported in samples in other Chinese provinces and higher than those in developed or industrialized countries, but significantly lower than contaminated area such as in India. The predominant pollutant in the HCH family is β-HCH. p,p′-DDE is a predominant pollutant in all DDEs and DDDs and DDTs for all the samples tested, and accounted for more than 80% of total HCHs and DDTs.     

Influence of sex, maturity and reproduction on PCB and p,p′DDE concentrations and repartitions in the European hake (Merluccius merluccius, L.) from the Gulf of Lions (N.W. Mediterranean)

The main objective of this work was to establish the influence of sex, maturity and reproduction on the contamination of the demersal fish Merluccius merluccius by organochlorine compounds. Polychlorinated biphenyls (PCBs) and p,p′DDE were quantified in muscle, liver and gonads of female and male hakes collected in the Gulf of Lions in 2004 and 2005. Observed levels appeared higher than the population of the Bay of Biscay and lower than the population of the Thyrrenian Sea. Contaminant fingerprints were roughly constant whatever the studied organ and the hake biological condition. Concentrations varied significantly according to the sex and maturity of hakes. Mature specimens were more contaminated than immature, and males presented higher levels than females. This sex effect can be linked to a lower growth rate of males, and a contaminant elimination during female spawning. Gonadal contamination depends on the importance of lipid content and increases with the maturation degree. Although the main organ of energy and PCB storage is the liver, muscle appears as the main contributor to the gonad contamination.