Concentrations Of Organochlorine Compounds Research Articles

Toxicokinetics of dioxins and other organochlorine compounds in Japanese people: Association with hepatic CYP1A2 expression levels

Concentrations of persistent organochlorine compounds (OCs) including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) in the liver and adipose tissue of Japanese cadavers were measured, and their toxicokinetics were examined in association with hepatic cytochrome P450 (CYP) 1A protein expression levels. Total 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) were 66±74 and 65±57pg/g lipid weight (mean±S.D.) in the liver and adipose tissue, respectively. Total PCBs (sum of 62 congeners targeted), p,p′-dichlorodiphenyl-dichloroethylene (p,p′-DDE) and β-hexachlorocyclohexane (β-HCH) were detected at concentrations over 1μg/g lipid in both tissues of some specimens. For most of the dioxin-like congeners, total PCBs, p,p′-DDE, oxychlordane, α- and β-HCH, hexachlorobenzene (HCB), and tris(4-chlorophenyl)methane (TCPMe), age-dependent increases in concentrations were found in the adipose tissue of males. No such age-dependent trend was observed in the liver, suggesting that there are different mechanisms underlying the hepatic concentrations of OCs. Immunoblot analyses indicated detectable expression of hepatic CYP1A2 protein, whereas no CYP1A1 protein was detected. The CYP1A2 expression levels were positively correlated with concentrations (on wet weight basis) of 2,3,4,7,8-P5CDF, the dominant TEQ-contributed congeners in the liver, indicating the induction of this CYP. Hepatic CYP1A2 protein levels were strongly correlated with the liver to adipose concentration (L/A) ratios of PCDD/F congeners with more than 5 chlorine atoms. Together with higher concentrations of the congeners in the liver than in the adipose tissue, the observation on L/A ratios of highly chlorinated PCDD/Fs suggests that induced hepatic CYP1A2 protein is involved in their sequestration in this human population, as observed in model animals (rodents). Nonetheless, the magnitude of hepatic sequestration (L/A ratio) of PCDD/Fs in this human population was lower than in other mammals and birds, reported previously. This study emphasizes the fact that toxicokinetics of some OCs can be affected at least partly by CYP1A2 protein levels in humans. For the extrapolation of their toxicokinetics from model animals to humans, knowledge on the induction and sequestration potencies of CYP1A is necessary.

Serum concentrations of persistent organic pollutants (POPs) in the inhabitants of a Sicilian city

BackgroundPolychlorinated biphenyls (PCBs) and organochlorine pesticides are common environmental contaminants that have been associated with human health problems. ObjectivesTo assess serum concentrations of several organochlorine contaminants in general population living in a city with an ancient agricultural tradition and to identify possible exposure sources in Sicily. MethodsA cross-sectional study was conducted on 101 individuals. Each participant answered a face-to-face questionnaire submitted by well-trained personnel and provided a serum sample which was analyzed for the concentrations of PCBs, HCB, HCHs and DDTs by using gas-chromatography coupled with mass spectrometry. ResultsHCB, p,p′-DDE, PCB 138, PCB 153 and PCB 180 were detected in more than 80% of the study participants. The ngg−1 lipid median concentrations were: 18.6 for HCB; 175.1 for p,p′-DDE; 22. for PCB 138; 32.5 for PCB 153 and 23.0 for PCB 180. PCB 153 and PCB 138, PCB 138 and PCB 180, PCB 153 and PCB 180, and p,p′-DDE and HCB showed a high correlation each other (p<0.05). HCB and p,p′-DDE concentrations were significantly higher in subjects >49years old (adj-p=0.03 in 50–69years old and adj-p<0.001 in >69years old, respectively) whereas PCB 138, PCB 153 and PCB 180 concentrations were higher in males (adj-p=0.03), in subjects >69years old (adj-p=0.04) and in current smokers (adj-p=0.04). ConclusionsThe present study shows that serum concentrations of organochlorine compounds detected in subjects living in a small Sicilian city with ancient agricultural tradition are similar to those found in subjects living in urban areas of other countries. However, further investigations are needed to compare data from rural/urban areas in the same country, assessing correlations between serum concentrations of several chemical compounds and potential health effects in general population.

Differences in organochlorine accumulation accompanying life history in the catadromous eel Anguilla japonica and the marine eel Conger myriaster

In order to examine the ecological risk for organic pollutants in diadromous fish migrating between sea and freshwater, organochlorine compounds (OCs) were determined in the catadromous eel Anguilla japonica having marine, estuarine and freshwater residence life histories. The eels were collected in Japanese coastal areas. We also compared the OCs accumulation with the marine eel Conger myriaster, which has a similar life history as A. japonica in the marine environment. The ontogenic changes in the otolith strontium (Sr) and calcium (Ca) concentrations were examined along the life history transect to discriminate the migration type. There were generally three different patterns, which were categorized as 'marine residence' (spent most of their life in the sea and did not enter freshwater), 'estuarine residence' (inhabited estuaries or switched between different habitats), and 'freshwater residence' (entered and remained in freshwater river habitats after arrival in the estuary) according to the otolith Sr:Ca ratio. There were generally no correlations between OCs such as Dichlorodiphenyltrichloroethanes (DDTs), Hexachlorobenzene (HCB), Hexachlorocyclohexanes (HCHs) and Chlordanes (CHLs) accumulation and each biological characteristic such as TL, BW and age in A. japonica. A positive correlation between the lipid content and concentrations of OCs were found. Additionally, the concentrations of HCB, ∑HCHs, ∑CHLs and ∑DDTs in A. japonica were significantly higher than those of C. myriaster, associating with the higher lipid contents (14% on average) in the former than the latter eels (9% on average). A negative linear relationship was found between the otolith Sr:Ca ratios and concentration of each OCs in A. japonica. The ecological risk of OCs increase as the freshwater residence period in the eel becomes longer. It is clear that migratory histories and lipid contents directly affected OCs accumulation in the anguillid eels.

Spatial distribution and temporal trends of persistent organochlorine pollutants in sediments from Lake Maryut, Alexandria, Egypt

Organochlorine compounds (OCs) in surface and core sediments collected from Lake Maryut, Egypt, were examined to elucidate their distribution, ecological risk and historical trend. To our knowledge, this is the first study on residue levels of OCs in sediments from Lake Maryut. Concentrations of PCBs and DDTs were higher than other OCs, ranging from 3.06 to 388 and from 0.07 to 106ng/g dry wt., respectively. The highest concentrations of OCs were found at stations near the discharge point of sewage and close to industrial areas. The distribution of DDT and its metabolites suggest no recent inputs into the lake environment. Contamination levels of sedimentary PCBs and DDTs, can be categorized moderate to high compared to other urbanized regions worldwide. Temporal trends in OCs levels were influenced by input pathways at two sites. Evaluation of ecotoxicological risks suggests that adverse biological effects are expected mainly in the main basin area.

Active biomonitoring in Greek coastal waters: Application of the integrated biomarker response index in relation to contaminant levels in caged mussels

An integrated approach using biomarkers and contaminant levels in mussels Mytilus galloprovincialis L. was employed to assess chemical contamination in Greek coastal waters within the framework of the MYTIMED program. Biomarkers (metallothioneins, glutathione S-transferase, catalase, acetylcholinesterase and RNA:DNA ratio) have been previously described in mussels caged at 14 sites in coastal areas influenced by different types of anthropogenic activities. This study applied a biomarker index, the Integrated Biomarker Response (IBR) to summarize biomarker responses and relate stress levels to concentrations of organochlorine compounds (PCBs, DDTs), polycyclic aromatic hydrocarbons (PAHs), and metals (Cu, Ni, Fe, Zn) measured in the mussel tissues. The IBR index indicated environmental stress at sites near cities and industries and was overall related to organic contaminants, but also elevated metal concentrations at certain sites. Slightly increased IBR values at few sites away from known pollution sources were not accompanied with increased contaminant levels suggesting stress possibly caused by natural factors. Results confirmed the usefulness of integration of biological effects measurements and chemical analysis for the assessment of chemical contamination in coastal waters.

Persistent organic pollutants in four bivalve species from Svalbard waters

Organochlorine compounds (OC) were determined in Arctic bivalves ( Mya truncata, Serripes groenlandicus, Hiatella arctica and Chlamys islandica) from Svalbard with regard to differences in geographic location, species and variations related to their size and age. Higher chlorinated polychlorinated biphenyls (PCB 101–PCB 194), chlordanes and α-hexachlorocyclohexane (α-HCH) were consistently detected in the bivalves and PCBs dominated the OC load in the organisms. OC concentrations were highest in Mya truncata and the lowest in Serripes groenlandicus. Species-specific OC levels were likely related to differences in the species’ food source, as indicated by the δ 13C results, rather than size and age. Higher OC concentrations were observed in bivalves from Kongsfjorden compared to the northern sampling locations Liefdefjorden and Sjuøyane. The spatial differences might be related to different water masses influencing Kongsfjorden (Atlantic) and the northern locations (Arctic), with differing phytoplankton bloom situations.

Prenatal Concentrations of Polychlorinated Biphenyls, DDE, and DDT and Overweight in Children: A Prospective Birth Cohort Study

Background: Recent experimental evidence suggests that prenatal exposure to endocrine-disrupting chemicals (EDCs) may increase postnatal obesity risk and that these effects may be sex or diet dependent.Objectives: We explored whether prenatal organochlorine compound (OC) concentrations [polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyltrichloroethane (DDT)] were associated with overweight at 6.5 years of age and whether child sex or fat intakes modified these associations.Methods: We studied 344 children from a Spanish birth cohort established in 1997–1998. Overweight at 6.5 years was defined as a body mass index (BMI) z-score ≥ 85th percentile of the World Health Organization reference. Cord blood OC concentrations were measured and treated as categorical variables (tertiles). Children’s diet was assessed by food frequency questionnaire. Relative risks (RRs) were estimated using generalized linear models.Results: After multivariable adjustment, we found an increased RR of overweight in the third tertile of PCB exposure [RR = 1.70; 95% confidence interval (CI): 1.09, 2.64] and the second tertile of DDE exposure (RR = 1.67; 95% CI: 1.10, 2.55), but no association with DDT exposure in the population overall. Associations between overweight and PCB and DDE concentrations were strongest in girls (p-interaction between 0.01 and 0.28); DDT was associated with overweight only in boys. For DDT we observed stronger associations in children with fat intakes at or above compared with below the median, but this interaction was not significant (p-interaction > 0.05).Conclusions: This study suggests that prenatal OC exposures may be associated with overweight in children and that sex and high-fat intake may influence susceptibility.

Risk Assessment of Organochlorine Compounds in Water and Surface Sediments from Taihu Lake and Nanjing Section of Changjiang, China

Samples of surface water and sediment were collected in Taihu Lake and Nanjing section of Changjiang. Organochlorine compounds(OCCs) of samples were detected to investigate the characteristics and ecological risk of them in the lake and river. The concentrations of OCCs in water of Nanjing section of Changjiang were higher than those in Taihu Lake, but the concentrations of OCCs in sediments were higher in Taihu Lake. HCHs of Taihu sediments were relatively enriched, indicating the agricultural source of compounds. PCBs of Changjiang sediments were higher compared to Taihu sediments, denoting a obvious industrial source. Comparing with other compartments in China, HCHs of the study area were higher than most sediment of Chinese rivers, DDTs didn’t show high contents in sediments, PCBs was in relatively low levels. By contrast with the relevant sediment quality guidelines of these compounds, the ecological risk of OCCs in sediments were evaluated. The OCCs of sediments in Taihu Lake and Nanjing section of Changjiang didn’t show high ecological risk.

PERSISTENT ORGANIC POLLUTANTS AND OVERWEIGHT AT AGE 6.5 YEARS; DO SEX OR HIGH-FAT INTAKES OF THE CHILD MATTER?

Background and Aims: Recent experimental evidence suggests prenatal exposure to endocrine-disrupting chemicals may increase postnatal obesity risk, and that these effects may vary by sex or be enhanced when animals are postnatally placed on a high-fat diet. Little is known about these associations in humans. We explored whether prenatal exposure to organochlorine compounds (OC) (PCBs, DDE, DDT) is associated with overweight at age 6.5 years and whether children’s sex or fat intakes modify these associations. Methods: We studied 344 children from a Spanish birth cohort established in 1997/98. OC concentrations were measured in cord blood. Overweight at 6.5 years was defined as a BMI z-score • the 85th percentile of the WHO reference. Using a food frequency questionnaire of children’s diet in the past year, a high-fat intake was defined as above median fat intakes as a percentage of energy. Weestimated relative risks using generalized linear models. Results: Third tertile PCBs exposure was found to be associated with overweight in girls (RRª=2.13, 95%CI=0.99, 2.57), but not clearly in boys (RRª=1.43, 95%CI=0.82, 2.38; p-interaction=0.04). Children with higher-fat intakes had an increased risk of overweight related to third tertile PCBs exposure (RRª=1.95, 95%CI=1.00, 3.82), but the interaction was not statistically significant (p-interaction=0.63). Second tertile DDE exposure was associated with overweight (RRª=1.67, 95%CI=1.10, 2.55), with a somewhat stronger association in girls than boys (p-interaction=0.20). No effect modification by fat intake was observed for DDE (p-interaction=0.93).Second tertile DDT exposure was associated with overweight only in boys (RRª=1.96, 95%CI=1.06, 3.62; p-interaction=0.25) and among children with higher-fat intakes (RR=2.31, 95%CI=1.16, 4.58; p-interaction=0.20). For none of the OC, linear dose-response relationships were observed. Conclusions: Though no clear evidence was found for a dose-response relationship, prenatal PCBs, DDE and DDT concentrations might increase the risk of overweight at 6.5 years in a sex-specific and diet-dependent way.

PRENATAL EXPOSURE TO DDE AND LOWER RESPIRATORY TRACT INFECTIONS (LRTIS) IN INFANTS: THE INMA PROJECT

Background and Aims: Growing evidence suggests that prenatal exposure to organochlorine compounds (OCs), mainly polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethylene (DDE), may increase the risk of respiratory infections in children through suspected immunotoxic mechanisms. Our aim is to examine, in the largest study so far, whether prenatal exposure to DDE increases the risk of LRTI in infants, and to isolate these effects from those of other OCs. Methods: The study is based on a cohort of 2150 mother-child pairs in Spain. Maternal serum concentrations of DDE and other OCs were measured during pregnancy. Parental reports of physician-confirmed diagnosis of LRTIs were obtained when children were 12-14 months old. Analyses were carried out separately for children from Spanish (N=1342) and Latin-American (N=79) mothers because of their different exposure profiles. Results: 35.4% of the children born to Spanish mothers developed at least one LRTI episode during their first 12-14 months of life. DDE exposure (median=116.3 ng/gr lipid) was associated with a higher risk of LRTIs (relative risk (95%CI) for 3rd quartile DDE exposure= 1.32 (1.08, 1.62)), which persisted after adjustment for other OCs (RR (95%CI) for 3rd quartile DDE = 1.38 (1.12, 1.71)). No association was found for other OCs. Stratified analyses showed that findings were homogeneous by study region, maternal smoking, maternal history of asthma and atopy, duration of predominant breastfeeding and maternal diet. Children born to Latin-American mothers, with much higher exposure to DDE (385.0 ng/gr lipid), showed a similar, but not statistically significant, increase in risk of LRTI with DDE exposure. Conclusions: Prenatal exposure to DDE is associated with higher risk of LRTIs in infants. Since LRTIs cause substantial morbidity in infancy and are a possible risk factor for subsequent childhood asthma, especial attention should be paid in countries where dichlorodiphenyltrichloroethane (DDT) is nowadays used for malaria control.

DISSIMILAR ACCUMULATION OF ORGANOCHLORINE COMPOUNDS, PBDES AND HBCD IN COLOSTRUM FROM MOTHERS LIVING IN URBAN/INDUSTRIAL AREAS ACCORDING TO GEOGRAPHIC ORIGIN

Background and Aims: Human milk is lipid-rich and a good store of lipophilic pollutants such as organohalogen compounds. This study is aimed to determine the accumulation patterns of organochlorine compounds (OCs), PBDEs and HBCD in colostrum samples of general population from two urban/industrial areas, to compare them and to identify the main determinants of their accumulation in these populations. Methods: 368 colostrum samples from Gipuzkoa and Sabadell INMA cohorts (1) were analysed for OCs (HCB, •-HCH, DDTs and PCBs), PBDEs (including BDE209) and HBCD. Maternal factors such as cohort area and geographic origin of mother were evaluated. Results: In both cohorts 4,4’-DDE was the most abundant pesticide and PCB153 the main PCB congener, whereas PBDE levels were one-fold lower than OCs, BDE153 being the most abundant congener. Median levels were similar to previous observations in other European studies (2, 3). HBCD was detected in more than 50% of samples, with similar levels to those found for main PBDEs. Gipuzkoa cohort had significantly higher levels of main OCs (especially PCBs) and PBDEs, compared to Sabadell. Regarding geographic origin of mothers in both cohorts, those from Latin America had significantly higher concentrations of 4,4’-DDT and 4,4-DDE than European mothers, whereas HCB, •-HCH, PCBs and BDE153 were significantly higher in European women than in those from Latin America. Conclusions: OCs and PBDEs were higher in Gipuzkoa than in Sabadell colostrum samples, reflecting the influence of heavy industry in Gipuzkoa area. In both cohorts, geographic origin of mothers was the main determinant of OC and PBDE concentrations. Those from Latin America have higher concentrations of 4,4’-DDT and 4,4’-DDE whereas European mothers exhibit higher concentrations of compounds of industrial origin. The higher accumulation of industrial pollutants is observed independently of the European banning regulations that control the present use of these compounds.

Prenatal Exposure to Organochlorine Compounds and Birth Size

To investigate the possible association between birth size and cord concentrations of some organochlorine compounds (OCs), including 4,4'-dichlorodiphenyltrichloroethane (DDT), 4,4'-1,1-dichloro-2,2-bis(p-dichlorodiphenyl)ethylene (DDE), hexachlorobenzene (HCB), β-hexachlorocyclohexane (β-HCH), 4 polychlorinated biphenyl (PCB) congeners (118, 138, 153, and 180), and their sum (ΣPCBs) in a birth cohort in Valencia, Spain. A total of 494 mothers and their newborns (born 2003-2006) participated in the study. Multivariate linear regression analyses were performed between birth weight, length, or head circumference and OC concentrations. Median concentrations of 4,4'-DDT, 4,4'-DDE, HCB, β-HCH, and ΣPCBs were 0.02, 0.46, 0.22, 0.09, and 0.35 ng/mL, respectively. For birth weight there was a significant decrease of 63 and 107 g for each 10-fold increase in cord serum 4,4'-DDT and 4,4'-DDE concentrations, and a marginally significant decrease of 79 and 53 g for each 10-fold increase in HCB and β-HCH concentrations. A significant decrease of 0.39 cm in birth length was found for each 10-fold increase in HCB concentrations. For newborns with cord 4,4'-DDT concentrations above the median there was a significant decrease of 0.26 cm in birth head circumference. These results reveal that prenatal exposure to some OCs could impair the anthropometric development of the fetus, reducing the birth weight, length, and head circumference.

Thyroid Dysfunction as a Mediator of Organochlorine Neurotoxicity in Preschool Children

Background: Exposure to organochlorine compounds (OCs) can alter thyroid function in humans, and hypothyroidism during early life can adversely affect a child’s neurodevelopment.Objectives: In this study we aimed to assess the relationship between developmental organochlorine exposures and thyroid function and the relationship between thyroid function and subsequent neurodevelopment.Methods: A population-based birth cohort of 182 children was followed annually up to 5.5 years of age. The assessments included OC concentrations in maternal pregnancy serum and milk, clinical thyroid parameters in maternal and cord serum, and subsequent neuropsychological outcomes of the child, along with sociodemographic cofactors. Resin triiodothyronine uptake ratio (T3RU) was also assessed as an estimate of the amount of thyroxine-binding globulin (TBG) sites unsaturated by thyroxine. The T3RU is high in hyperthyroidism and low in hypothyroidism.Results: The findings showed consistent inverse and monotonic associations between organochlorine exposure and T3RU after covariate adjustments. We observed no associations with other thyroid parameters. T3RU was positively associated with improved performance on most of the neuropsychological tests. For other thyroid parameters, the findings were less consistent.Conclusions: The results suggest that OC exposures may decrease the T3RU during early life, which is a proxy measure of the binding capacity of TBG. In addition, minor decreases of the thyroid function may be inversely associated with a child’s neurodevelopment.

Distribution and sources of organochlorinated contaminants in sediments from Izmir Bay (Eastern Aegean Sea)

Eighteen surface sediment samples representative of the entire Izmir Bay were analyzed for organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). This was in order to provide extensive information concerning the recent deposition of these compounds in this area, together with levels, distribution, possible sources and potential biological risk. Sites that were contaminated by high concentrations of organochlorine compounds were associated with dense population, such as the harbour and the Gediz River estuary. Relatively higher ΣDDT concentrations and high DDT/DDE+DDD ratios in the Gediz River estuary indicated DDT usage, probably linked to public health emergencies. According to the established guidelines for sediment quality, the risk of adverse biological effects from such levels of OCPs and PCBs as recorded at most of the study sites was insignificant. But the higher concentrations in Inner bay and in the Gediz River estuary could cause biological damage.

Contamination status and spatial distribution of organochlorine compounds in fishes from Nansei Islands, Japan

Two species of fishes (n=52; tilapia and mullet) from industrialized and urbanized areas of Okinawa Island (Manko-Noha river, Hija river and Shikaza river) and from a remote area of Ishigaki Island (Anparu mudflat), Japan were collected between August 2005 and July 2006, and analyzed for five organochlorine compounds (OCs), viz., DDTs, PCBs, CHLs, HCHs and HCB. Concentrations and the contamination patterns of OCs in fishes varied between locations. Considerable residue levels of OCs, especially CHLs and DDTs were found in both fishes from the main Okinawa Island. These levels were relatively higher than the reported values for seafood from Japanese coasts, indicating that even now pollution sources of these contaminants still exist in this region. On the other hand, lower concentrations of OCs were detected in fishes from Ishigaki Island waters than those of other Japanese coastal waters, suggesting that this region is less contaminated by OC contaminants.

Relationships between occupational history and serum concentrations of organochlorine compounds in exocrine pancreatic cancer

BackgroundPrevious studies investigating associations between occupational history and risk of exocrine pancreatic cancer (EPC) did not use biomarkers of exposure. The only two studies that measured internal concentrations of organochlorine...

Sociodemographic, reproductive and dietary predictors of organochlorine compounds levels in pregnant women in Spain

Organochlorine pesticides and polychlorinated biphenyls (PCBs) are consistently found in human tissues. Serum levels of organochlorine compounds (OC) in pregnant women in particular have raised concern about possible harm to humans in the early phases of physical and behavioural development. The objective of the present study was to evaluate the association between concentration of OCs in serum of two cohorts of pregnant women from Gipuzkoa and Sabadell in Spain and socioeconomic, reproductive and dietary variables. Concentration of polychlorinated biphenyls (PCBs: 28, 52, 101, 118, 138, 153 and 180), hexachlorobenzene (HCB), beta and gamma-hexachlorocyclohexane ( β-HCH and γ-HCH), heptachlor epoxide, dichlorodiphenyl dichloroethylene ( p,p′-DDE) and dichlorodiphenyl trichloroethane ( p,p′-DDT) were measured in the serum of 1259 pregnant women. Associations between OCs and potential predictor variables were assessed using linear regression models adjusted for potential confounders. The compounds most commonly found in the serum were p,p′-DDE (99% of the samples) and PCB-153 (95% of the samples). Geometric means of serum concentrations (ng g −1 lipid) of organochlorine pesticides were 110.0, 19.1, and 33.5 for p,p′-DDE, β-HCH, and HCB respectively, while the geometric means of PCBs were 21.8, 38.9 and 26.9 for PCB 138, 153, and 180 respectively. The levels of all OCs increased with age. BMI was positively associated with the concentration of organochlorine pesticides but inversely related to PCB concentrations. The serum levels of OCs fell only after a cumulative period of breastfeeding of over a year. Levels of PCBs were related to fish intake, but in general dietary factors did not improve the explained variability of the concentrations of OCs. Overall, the levels of OCs found in the study are at the lower end of the range reported in Spain and other countries.

Levels and Distribution of PCBs and Organochlorine Pesticides in the Air, Pine Needles, and Human Milk

This review presents the findings on the distribution and levels of 20 congeners of polychlorinated biphenyls (PCBs) and 7 organochlorine pesticides (OCPs) all over the world, based on measurements in samples of air, human milk and pine needles. The Institute for Medical Research and Occupational Health has been conducting research in all three matrices for many years, and this review summarises its results too. Significant decrease in concentrations of organochlorine compounds has been seen after the legal ban of their use, but that decresing trend has been slowed down and they are still found in all samples. In general, higher PCB levels are found in samples from urban locations, pesticides levels are higher in samples from locations where has been their probable usage in agriculture, while HCB levels are usually indicator of industrial activity.γ-HCH has been found in the highest concentration in air and pine needles samples, while in humans DDE and β-HCH are the most abundant compounds. Indicator PCB congeners are also differently present in environment and humans: in air and pine needles lower-chlorinated, more volatile PCB congeners have higher concentrations while in humans that goes for more persistent higher-chlorinated PCB congeners. Among toxic ortho-substituted PCB congeners in human and environmental samples the most abundant is PCB-118 while three non-ortho substituted congeners (PCB-77, PCB-126 and PCB-169) that are the most toxic ones are rarely detected. From organochlorine pesticides, DDD is found in lowest concentrations in all samples.

Maternal Origin and Other Determinants of Cord Serum Organochlorine Compound Concentrations in Infants from the General Population

Organochlorine compounds (OCs), including pesticides and polychlorobiphenyls (PCBs), were determined in the serum of 499 cord blood samples from infants born during 2004-2006 in Valencia (Spain). The concentrations were found to be correlated with the region of origin of the mothers. Those from Latin-America gave birth to infants with higher 4,4'-DDE and 4,4'-DDT concentrations than those from Europe. On the contrary, European mothers had children with higher concentrations of hexachlorobenzene and PCBs than Latin-American mothers. These associations were independent of maternal period of stage in Valencia. Data examination with a multivariate model including maternal region of origin described 39-44% of the concentration variability of 4,4'-DDE and total PCBs with statistic significance. Other maternal variables found to significantly influence OC burden in newborns were age, education level, and body mass index (BMI). In general, older women, with higher education standards and higher BMI had infants with higher OC serum concentrations than younger women, with lower education scores and low BMI. The increase of 4,4'-DDT in newborns from mothers with high education levels and high BMI suggest that dissimilar maternal diets may be at the origin of some of these OC body burden differences.

Bioavailability of organochlorine compounds in aqueous suspensions of fullerene: Evaluated with medaka ( Oryzias latipes) and negligible depletion solid-phase microextraction

The wide application of engineered nanomaterials, such as fullerene (C 60), will inevitably lead to their release into the aqueous environment, which may alter the bioavailability of organic compounds to aquatic organisms. Negligible depletion solid-phase microextraction (nd-SPME) together with medaka ( Oryzias latipes) bioaccumulation were used to study the effects of aqueous suspensions of fullerene ( nC 60) on the bioavailability of eight organochlorine compounds (OCCs) (log K OW 3.76–6.96). Freely dissolved concentrations of OCCs decreased by 11.5–88.4% at addition of 5 mg L −1 nC 60 as indicated by reduced equilibrium concentrations in the SPME fiber coating, the highest reduction being observed for the most hydrophobic OCCs. Medaka bioaccumulation study demonstrated that at the kinetic uptake regime, nC 60 significantly decreased the bioaccumulation of the high hydrophobic OCCs (log K OW > 6), but slightly enhanced the bioaccumulation of the less hydrophobic OCCs (log K OW < 6). The OCC concentrations in medaka ( C fish) at the kinetic uptake regime linearly correlated with that in nd-SPME fiber ( C fiber) without nC 60 ( p = 0.007–0.013, R 2 = 0.666–0.723), but this correlation deteriorated with the presence of nC 60 ( p = 0.073–0.081, R 2 = 0.423–0.440). These results suggest that in nC 60 the uptake mechanism of OCCs to medaka is different from that to nd-SPME fiber. While only the freely dissolved OCCs are available to nd-SPME fiber, both the freely dissolved and the nC 60 associated OCCs contributed to the accumulation of OCCs to medaka.