Relative effects of educational level and occupational social class on body concentrations of persistent organic pollutants in a representative sample of the general population of Catalonia,Spain

Scant evidence is available worldwide on the relative influence of occupational social class and educational level on body concentrations of persistent organic pollutants (POPs) in the general population. The objective was to analyse such influence in a representative sample of the general population of Catalonia, Spain. Participants in the Catalan Health Interview Survey aged 18–74 were interviewed face-to-face, gave blood, and underwent a physical exam. The role of age, body mass index (BMI), and parity was analysed with General Linear Models, and adjusted geometric means (GMs) were obtained. Crude (unadjusted) concentrations were higher in women and men with lower education, and in women, but not men, in the less affluent social class. After adjusting for age, in women there were no associations between POP levels and social class or education. After adjusting for age and BMI, men in the less affluent class had higher p,p′-DDE concentrations than men in class I (p-value = 0.016), while men in class IV had lower HCB than men in the upper class (p-value < 0.03). Also in contrast with some expectations, positive associations between education and POP levels were observed after adjusting for age and BMI in men; e.g., men with university studies had higher HCB concentrations than men with first stage of primary schooling (adjusted GM 153.9 and 80.5 ng/g, respectively) (p-value < 0.001). When education and social class were co-adjusted for, some positive associations with education in men remained statistically significant, whereas class remained associated only with p,p′-DDE. Educational level influenced blood concentrations of POPs more than occupational social class, especially in men. In women, POP concentrations were mainly explained by age/birth cohort, parity and BMI. In men, while concentrations were also mainly explained by age/birth cohort and BMI, both social class and education showed positive associations. Important characteristics of socioeconomic groups as age and BMI may largely explain crude differences among such groups in internal contamination by POPs. The absence of clear patterns of relationships between blood concentrations of POPs and indicators of socioeconomic position may fundamentally be due to the widespread, lifelong, and generally invisible contamination of human food webs. Decreasing historical trends would also partly explain crude socioeconomic differences apparently due to birth cohort effects.     

Dietary, age and trans-generational effects on the fate of organohalogen contaminants in captive sledge dogs in Greenland

Studies on the fate of organohalogen contaminants (OHCs) in wild top predator mammals in the Arctic have often been a challenge due to important knowledge deficiencies in the life history of the sampled animals. The present study investigated the influence of age, dietary and trans-generational factors on the fate of major lipophilic chlorinated and brominated OHCs in adipose tissue of a potential surrogate captive species for the polar bear (Ursus maritimus), the sledge dog (Canis familiaris) in West Greenland. Adult female sledge dogs (P) and their sexually-mature (F1) and/or pre-weaning pups (F1-MLK) were divided into an exposed group (EXP) fed blubber from a Greenland minke whale (Balaenoptera acutorostrata) and a control group (CON) given commercially available pork fat. Large dietary treatment-related differences in summed and individual congener/compound adipose tissue concentrations of polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), chlordanes (CHLs) and polychlorinated biphenyls (PCBs) were found between the EXP and CON groups for all the sledge dog cohorts. However, among the F1-MLK, F1 and P dogs in both of the EXP and CON groups, little or no difference existed in PBDE, HCB, CHL and PCB concentrations, suggesting higher state of equilibrium in adipose tissue concentrations from a very early stage of life. In contrast, the distribution pattern (proportions to the summed concentrations) of OHC classes, and the major congeners/compounds constituting those classes, varied on a dietary group- and/or cohort-dependent manner. The present captive sledge dog study demonstrated the importance of the confounding effects of diet composition, mother-pup association (maternal transfer), reproductive status (nursing), and to a lesser extent age in the fate of OHCs in adipose tissue of a large top carnivore mammal.     

Hair mercury levels in an urban population from southern Italy: fish consumption as a determinant of exposure

Mercury levels in hair of a general population, 237 adults aged between 35-45, in Naples, Italy, were assessed. The subjects were asked to fill in a questionnaire about age, gender, body weight, height, body mass index (BMI), fish consumption, number, surface and area of dental amalgam fillings. Total mercury (THg) concentrations in human hair ranged from 0.221 to 3.402 microg/g and the mean value for the subjects under study was 0.638 microg/g. Study participants were divided into three groups in accordance with fish consumption and dental amalgam: ANF (amalgam and no fish); NAF (no amalgam but with fish) and AAF (amalgam and fish). Significant differences in THg were found in the three groups (p<0.05). A multiple linear regression analysis showed a weak but significant correlation of THg content in hair with respect to gender and age, but almost no association was found between THg and dental fillings. Conversely, a strong correlation was obtained between THg and fish consumption regardless of the group evaluated. Finally, mercury levels in hair exceeded the levels corresponding to the EPA reference dose (RfD) of 0.1 microg Hg/kg body weight per day (1 microg Hg/g hair) in 6% of the population (4% men and 2% women). However, the THg limits in our subjects were not exceeded according to the WHO guidelines, which use a benchmark dose of 0.23 microg Hg/kg bw/day (14 microg Hg/g maternal hair).     

Exposure and body burden of polychlorinated biphenyls (PCB) and metals in a historically contaminated community

There are many small villages where environmental contamination is substantial due to historical industrial activities. The aim of the present study was to investigate if long-term or current consumption of local foods, as reported in food frequency questionnaires, co-vary with measured concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), lead (Pb), cadmium (Cd) and mercury (Hg) in blood, urine and hair from a population living in a historically contaminated village.Blood, urine and hair were provided by men (n = 38) and women (n = 57), who had participated in a previous case–control study in the contaminated area, and were analyzed for PCB, OCPs, Pb, Cd and Hg. A detailed food frequency questionnaire, used in the previous epidemiological study, was repeated, and up-dated information of life-style, exposure factors and other covariates was collected. Associations between reported consumption of local foods and exposure biomarkers were explored in relation to age, gender, life-style factors and other covariates.A large part of the population in the area reported consumption of local food, and thus, was potentially exposed to the contaminants. Despite the limited number of participants and other weaknesses described, it was possible to link reported consumption of different foods to biomarker concentrations.Reported consumption of local vegetables, forest berries and mushrooms co-varied with urinary Cd, indicating an influence from the contaminated area on the Cd exposure. We found no associations between PCB plasma concentrations with reported consumption of local fish, but with consumption of herring (non-local sea fish) which is typically high in PCB. Pesticide (HCB, p,p′-DDE, trans-nonachlor) exposure was mainly associated with agricultural work and having a private well the first five years of life, but we found no associations between pesticide concentrations in plasma and consumption of local vegetables or fish. Exposure to Hg was associated with consumption of fish, both local and non-local, and Pb exposure was associated with the consumption of game.Overall, the contaminant concentrations measured in blood, urine and hair varied substantially among study participants, but on average, the concentrations were similar to concentrations measured in other groups of the general Swedish population in the same age range. Larger studies are needed to evaluate health risks (and causality) associated with historical environmental contamination.     

Polybrominated diphenyl ethers and polychlorinated biphenyls in human breast adipose samples from Brazil

Twenty five human breast adipose tissue samples were collected in Porto Alegre, Brazil during 2004-2005 and analyzed for polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). SigmaPBDE concentrations (sum of tri- to hepta-BDEs) ranged from 0.19 to 132 ng/g lipid with a median of 1.51 ng/g lipid. These concentrations are 3- to 100-times lower than those reported from other countries, with the exception of Japan, probably reflecting lower usage of PBDE-containing products or lower exposures to these chemicals. The predominant congener was BDE-47, followed by BDEs 99, 183, 153 and 100. One individual in the dataset had about 70-times higher PBDE concentrations than the rest of the participants. SigmaPCB (sum of PCBs 118, 138, 153, 180) ranged from 30 to 339 ng/g lipid, with a median of 51 ng/g lipid. No age dependency was found for PBDEs (r=-0.800-0.374, p>0.05) or PCB 180 (r=0.278, p>0.05). On the other hand, PCBs 118, 138 and 153 did show age dependency (r=0.410-0.458, p<0.05). This is the first study to report levels of PBDEs in human breast adipose from Brazil.     

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 ± 57 pg/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 1 μg/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.     

Circulating levels of Persistent Organic Pollutants (POPs) among elderly men and women from Sweden: Results from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS)

Persistent Organic Pollutants (POPs) are a huge group of chemicals that have been linked to various adverse health effects in humans. Large epidemiological studies investigating gender differences in levels of POPs in the elderly are limited and the results from these are not always consistent. The present study was undertaken to examine the background levels of a broad range of POPs in human plasma samples among elderly men and women from Sweden and to assess the influence of gender. Levels of 23 POPs were determined in plasma samples collected during 2001–2004 from 1016 (50.2% women) 70 year-old participants from the population-based Prospective Study of the Vasculature in Uppsala Seniors (PIVUS). Measurements were performed using high resolution gas chromatography with high resolution mass spectrometry (HRGC-HRMS) and the POPs studied were 16 polychlorinated biphenyls (PCBs), five organochlorine (OC) pesticides, one dioxin, and one brominated flame retardant. The concentrations of the selected POPs were found similar, or comparable, to other studies of non-occupationally exposed populations from Sweden and Europe. Differences in levels of POPs between men and women were assessed by using Wilcoxon rank-sum (Mann–Whitney) test. Significant (p < 0.0001) gender differences in levels of specific POPs were observed and a number of POP concentrations were found to differ between men and women. More specifically, levels of HCB, OCDD, and PCB congeners #74, #105, and #118 were found to be higher in women, while the rest of the majority of POPs were higher in men.     

The influence of lipid and lifestyle factors upon correlations between highly prevalent organochlorine compounds in patients with exocrine pancreatic cancer

We aimed to analyse the influence of cholesterol and triglycerides, and of tobacco, coffee and alcohol consumption upon correlations between serum concentrations of organochlorine compounds (OCs) in patients with exocrine pancreatic cancer (EPC). Incident cases of EPC diagnosed in eastern Spain were prospectively identified (N=144). OCs were analysed by high-resolution gas chromatography with electron-capture detection. A strong correlation was observed between hexachlorobenzene (HCB) and beta-hexachlorocyclohexane (beta-HCH) (Spearman's rho=0.758). beta-HCH showed rho>0.4 with p,p'-DDT, p,p'-DDE, PCB138 and PCB153 (all p<0.001). Some correlations among compounds were slightly affected by tobacco, coffee or alcohol consumption. We observed a striking diversity of correlation patterns by strata of cholesterol and triglycerides. Most correlations were higher in the lowest category of triglycerides than in the lowest category of cholesterol. Most coefficients above 0.7 were seen in the lowest category of triglycerides (e.g., OC pairs p,p'-DDT and HCB, p,p'-DDT and beta-HCH, p,p'-DDE and beta-HCH, or HCB and beta-HCH). Correlations among OCs may be stronger when concentrations of triglycerides are low than when they are high. This is compatible with a dilution in the early phases of cancer and with a concentration effect as triglycerides become lower in the advanced phases of the disease.     

Serum concentrations of major perfluorinated compounds among the general population in Korea: Dietary sources and potential impact on thyroid hormones

Perfluorinated compounds (PFCs) have been frequently detected in both the environment and biota, and have become a growing concern. However, information is limited on the potential sources and human health implications of such exposure. We evaluated the exposure levels of 13 major PFCs among a population (n = 633, > 12 years of age) in a mid-sized city of Korea, and investigated for their potential dietary sources and the impact on thyroid hormone concentrations. For this purpose, we collected blood samples from a general population in Siheung, Korea and measured for 13 PFCs, total thyroxine (T4), and thyroid stimulating hormone (TSH). In addition, a questionnaire survey on diet was conducted. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) were detected in relatively greater concentrations than the other 9 PFCs in the blood serum. Males tend to have greater concentrations than females for most PFCs, and the concentrations were elevated as age increased up to 50s. Body mass index (BMI) was also shown to influence the serum concentrations of several PFCs. After adjustment for age, sex, and BMI, the consumption of vegetable, potato, fish/shellfish, and popcorn was identified to be significantly related with concentrations of major PFCs in blood. Among the studied PFCs, the concentrations of perfluorotridecanoic acid (PFTrDA) were negatively correlated with total T4, and positively with TSH levels, especially among females. The result of this study will provide information useful for developing public health and safety management measures for PFCs.     

Association of serum concentration of organochlorine pesticides with dietary intake and other lifestyle factors among urban Chinese women

Concerns about the carcinogenic and endocrine-disrupting characteristics of organochlorine pesticides (OCPs) have led to a global ban on OCP use. However, OCPs persist in the environment for decades because of their long half-life. We evaluated serum levels of OCPs and their correlations with usual dietary intake and other lifestyle factors among 250 healthy women who participated as controls in the Shanghai Breast Cancer Study. Serum levels of hexachlorocyclohexane isomers (alpha-HCH, beta-HCH, gamma-HCH), dichloro-di-phenyl-trichloroethane (DDT) isomers (p,p'-DDE and p,p'-DDT), hexachlorobenzene (HCB), trans-nonachlor (TNC), and eight polychlorinated biphenyls (PCB) congeners (IUPAC no. 74, 118, 138, 153, 170, 180, 183, and 187) were measured. Lifestyle factors and usual dietary habits over the past 5 years were assessed through an in-person interview. With the exception of PCB, total OCP levels in our study population were significantly higher than those observed in other countries. Age, income, body mass index, waist-to-hip ratio, number of pregnancies, and/or total duration of breastfeeding were all significantly correlated with all types of OCPs. Of the 20 food groups evaluated, correlations with serum total OCPs were observed for eggs (r=0.13), fresh beans (r=-0.17), tea (r=0.14), and animal fat (r=0.18). Multiple regression analyses showed that age and animal fat intake were positively associated with serum total level OCPs, while leafy vegetable and fresh bean consumption was negatively associated with OCPs level. Our study suggests that dietary intake may be an important contributor of serum levels of OCPs in Chinese women.     

Polychlorinated biphenyl levels in adipose tissue of primiparous women in Turkey

Polychlorinated biphenyls (PCBs) are a mixture of 209 possible congeners with different chlorine substitutions and they are potentially hazardous compounds in the environment for human beings. The high lipophilicity and the resistance to biodegradation of PCBs allow the bioaccumulation of these chemicals in the fatty tissues of organisms. The objective of this study was to determine the levels of PCBs in the adipose tissue of women living in Ankara, Turkey. For this purpose, levels of seven major persistent PCB congeners (IUPAC Numbers: 28, 52, 101, 118, 138, 153, 180) were measured in 29 primiparous mothers' adipose tissue samples by gas chromatography with electron capture detection (GC-ECD). PCB IUPAC numbers 138, 153 and 180 were the most abundant congeners, each accounting for > 20% of the total PCB content of adipose tissue. PCB 153 was the dominant congener in all the samples (141.7 +/- 132.3 ng/g lipid wt. basis). The results are compared with the similar studies from other countries. The concentrations of PCB 28, PCB 52 and PCB 101 were found to be higher than those found in industrialized countries. This study is important in terms of being the first study of determination of PCB levels in adipose tissue samples in Turkey.     

Exposure to mixtures of organohalogen contaminants and associative interactions with thyroid hormones in East Greenland polar bears (Ursus maritimus)

We investigated the multivariate relationships between adipose tissue residue levels of 48 individual organohalogen contaminants (OHCs) and circulating thyroid hormone (TH) levels in polar bears (Ursus maritimus) from East Greenland (1999-2001, n=62), using projection to latent structure (PLS) regression for four groupings of polar bears; subadults (SubA), adult females with cubs (AdF_N), adult females without cubs (AdF_S) and adult males (AdM). In the resulting significant PLS models for SubA, AdF_N and AdF_S, some OHCs were especially important in explaining variations in circulating TH levels: polybrominated diphenylether (PBDE)-99, PBDE-100, PBDE-153, polychlorinated biphenyl (PCB)-52, PCB-118, cis-nonachlor, trans-nonachlor, trichlorobenzene (TCB) and pentachlorobenzene (QCB), and both negative and positive relationships with THs were found. In addition, the models revealed that DDTs had a positive influence on total 3,5,3'-triiodothyronine (TT3) in AdF_S, and that a group of 17 higher chlorinated ortho-PCBs had a positive influence on total 3,5,3',5'-tetraiodothyronine (thyroxine, TT4) in AdF_N. TH levels in AdM seemed less influenced by OHCs because of non-significant PLS models. TH levels were also influenced by biological factors such as age, sex, body size, lipid content of adipose tissue and sampling date. When controlling for biological variables, the major relationships from the PLS models for SubA, AdF_N and AdF_S were found significant in partial correlations. The most important OHCs that influenced TH levels in the significant PLS models may potentially act through similar mechanisms on the hypothalamic-pituitary-thyroid (HPT) axis, suggesting that both combined effects by dose and response addition and perhaps synergistic potentiation may be a possibility in these polar bears. Statistical associations are not evidence per se of biological cause-effect relationships. Still, the results of the present study indicate that OHCs may affect circulating TH levels in East Greenland polar bears, adding to the "weight of evidence" suggesting that OHCs might interfere with thyroid homeostasis in polar bears.     

A novel model to characterize postnatal exposure to lipophilic environmental toxicants and application in the study of hexachlorobenzene and infant growth

BackgroundInfants are exposed to persistent environmental contaminants through breast milk, yet studies assessing the health effects of postnatal exposure are lacking. Existing postnatal exposure assessment is either too simple (lactation exposure model, LEM) or requires complex physiologically-based pharmacokinetic (PBPK) models.ObjectivesWe present equations for postnatal exposure calculations. We applied these equations to study the effect of hexachlorobenzene (HCB) on infant growth in the two first years of life.MethodsHCB was measured in breast milk samples in 449 mother-child pairs participating in the Norwegian birth cohort study HUMIS. We used these concentrations, mother's weight, height and age, together with child's weight at 8 age points, and proportion of milk consumed each month, to calculate HCB concentrations in the infant over age. We then estimated the association between HCB and infant growth using a linear mixed model.ResultsChildren exposed to HCB via mother's milk reached concentrations 1–5 times higher than the mother. HCB was associated with lower weight gain in the first 2 years (− 33 g per unit HCB and month, 95% CI: − 38, − 27 at 6 months). Associations were stronger during the first 3 months (− 57 g per unit HCB and month, 95% CI: − 67, − 49 at 1 month), indicating a critical window of effect. Our equations gave more precise estimates than the LEM.ConclusionOur equations for postnatal exposure of lipophilic environmental toxicants give better results than the LEM and are easier to implement than the complex PBPK models. HCB exposure, especially during the first three months of life, has a negative effect on infant growth up to 2 years.     

Health effects and exposure to polychlorinated biphenyls (PCBs) and metals in a contaminated community

Environmental measurements carried out by local authorities during the 1970s, 80s and 90s in an area contaminated by hundreds of years of industrial activities have revealed high levels of zinc (Zn), copper (Cu), lead (Pb) and cadmium (Cd) in soil, vegetables, root crops, berries and mushrooms. In 1972, a large quantity of oil contaminated with polychlorinated biphenyls (PCBs) was accidentally spilled into the river running through the village. To investigate the possible health effects of exposure from local sources, all cancer diagnoses, registered in 1960–2003 for individuals living in the study area, were collected from the regional cancer register of southeast Sweden. The total cancer incidence was non-significantly decreased both among males and females as compared to national rates (SIR = 0.91) for each gender. Among males, increased risks, of border-line significance, were seen for testicular cancer and lymphomas as well as significantly decreased risks for cancer in the rectum, respiratory system and brain. Information on lifetime residence, occupation, smoking habits, diseases, childbirth and food consumption, was collected via questionnaires from cancer cases and randomly selected controls. In both genders combined, significant associations were found for total cancer and high consumption of local perch, and for lymphomas and high consumption of both perch and pikeperch. Female breast cancer was significantly associated with high consumption of local perch and pike as well as with work in metal production. Mothers residing in the parish before the age of five reported significantly more preterm child deliveries. In spite of study limitations, the results indicate that residing in a rural contaminated area may contribute to the development of certain cancers and reproductive effects. In females, high consumption of local fish was shown to be the strongest determinant for total cancer, while in males, the strongest determinant was residing in the study area the first five years of life. Further research including validation of exposure using biomarkers is required to verify the findings as well as future studies in other polluted areas in Sweden with larger population bases.     

Levels of polybrominated diphenyl ethers (PBDEs) in breast milk from central Taiwan and their relation to infant birth outcome and maternal menstruation effects

In utero exposure to polybrominated diphenyl ethers (PBDEs) reduces the number of ovarian follicles in rat females and causes permanent effects on rat males. Little data have been gathered on the associations between PBDEs exposure and birth outcome and female menstruation characteristics in both epidemiological and animal studies. The aim of this study was to examine how PBDEs in breast milk are associated with infant birth outcome and maternal menstruation characteristics. Study participants were healthy women recruited from central Taiwan between December 2000 and November 2001. Twelve congener levels of PBDEs (BDE-17, 28, 47, 66, 85, 99, 100, 138, 153, 154, 183, 209) in 20 breast milk samples were measured by gas chromatography with high resolution mass spectrometer. The mean level of PBDEs in breast milk was 3.93+/-1.74 ng/g lipid. The estimated PBDE daily intake for a breastfed infant was 20.6 ng/kg b.w./day after delivery. After maternal age, pre-pregnant BMI, and parity were adjusted, increased PBDEs in breast milk was related with decreased birth outcome, particularly for birth weight and length, chest circumference, and Quetelet's index of infants. No significant differences in PBDEs were found between the two groups of menstrual cycle length higher and lower than 30 days after we adjusted for maternal age, pre-pregnant BMI, and parity. In utero exposure to low doses of PBDEs may result in lower birth weight and short or birth length. Our findings are limited based on the low doses of PBDEs and the small sampling size.     

Brominated flame retardants and other organochlorine pollutants in human adipose tissue samples from the Czech Republic

Brominated flame retardants (BFRs) represented by polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) together with major persistent organochlorine pollutants, polychlorinated biphenyls (PCBs) and selected organochlorine pesticides (OCPs), were determined in adipose tissue samples (n=98) obtained by liposuction of Czech subjects. Compared to other organochlorine pollutants (mostly PCBs and DDTs), levels of PBDE were lower by 2 orders of magnitude ranging from 0.2 to 54.3 ng/g lipid weight. PBDE congeners No. 47, 99, 153 and 183 were the most abundant constituting up to 90% of these pollutants in adipose tissue. The PBDEs content measured in this study was comparable with data reported in similar samples collected in Spain, Sweden, Belgium and Japan, whilst slightly lower than in the United States. Regarding PCBs, the dominating congeners were No. 138, 153 and 180 representing up to 90% of indicator congeners. The levels of PCBs were similar to those found in other European countries. While no age dependency was found for PBDEs, an increase of PCB and OCP levels with age was observed. Different exposure routes of donors were documented by the absence of the relationship between PCBs and OCPs.     

Fetal methylmercury exposure as measured by cord blood mercury concentrations in a mother-infant cohort in Hong Kong

This study was designed to examine newborn infants in Hong Kong prenatally exposed to levels of methylmercury considered to increase risk of neurotoxic effects and to examine subject characteristics that modify the degree of prenatal mercury exposure. Mercury concentrations in 1057 sets of maternal and cord blood samples and 96 randomly selected maternal hair samples were measured. Subject characteristics were measured or collected by questionnaire. Of the 1057 cord blood samples collected only 21.6% had mercury concentrations less than 29 nmol/L (5.8 micro g/L). Median maternal hair mercury concentration was 1.7 ppm. The geometric mean cord to maternal blood mercury ratio was 1.79 to 1. Increasing maternal fish consumption and maternal age were found to be associated with increased cord blood mercury concentrations. Marine fish consumption increased cord blood mercury concentrations more than freshwater fish (5.09%/kg vs 2.86%/kg). Female babies, maternal alcohol consumption and increasing maternal height were associated with decreased cord blood mercury concentrations. Pregnant women in Hong Kong consume large amounts of fish and as a result, most of their offspring have been prenatally exposed to moderately high levels of mercury. In this population, pregnant women should choose freshwater over marine fish and limit fish consumption.     

性腺发育及年龄对养殖中华鲟抗氧化力的影响

以养殖的子一代（n=21）中华鲟为对象,研究了性腺发育及年龄对其抗氧化力的影响。结果表明：（1）1998年生子一代雌性(未达性成熟,性腺处于慢速发育阶段)和雄性(接近性成熟,性腺处于开始快速发育阶段)的睾酮和雌二醇/睾酮差异显著,雌性血清丙二醛水平显著低于雄性,而超氧化物歧化酶和谷胱甘肽过氧化酶的活力及超氧化物歧化酶/丙二醛值虽高于雄性,但二者间不存在显著性差异,雌性和雄性的丙二醛与超氧化物歧化酶/丙二醛之间相关性极显著（r=-0915,-0818,P＜001);（2）雌二醇/睾酮值与丙二醛显著负相关,与超氧化物歧化酶/丙二醛显著正相关（r=-0635,r=0709,P＜005）,与超氧化物歧化酶、谷胱甘肽过氧化酶无显著相关性;（3）4个年龄组（4、8、11、12龄,未达性成熟）的超氧化物歧化酶和丙二醛无显著性差异,12龄组的谷胱甘肽过氧化酶显著低于其余3组,而超氧化物歧化酶/丙二醛显著高于其余3组,谷胱甘肽过氧化酶和丙二醛与年龄呈负相关（r=-0547,P＜001;r=-0519,P＜005）,超氧化物歧化酶/丙二醛与年龄呈正相关（r=0569,P＜001）。这表明进入性腺快速发育阶段的雄性氧化应激水平明显高于处于性腺慢速发育阶段的同龄雌性;随着年龄增长,未达性成熟中华鲟的抗氧化力水平逐渐增强;使用以上指标作为亚健康群体的筛选指标和氧化应激的生物标志物时,应充分考虑监测群体性腺发育和年龄因素,以使参考指标更准确     

Organochlorine and heavy metals in newborns: Results from the Flemish Environment and Health Survey (FLEHS 2002–2006)

To collect regional information on internal levels of pollutants in humans in Flanders, 1196 mother–child pairs were systematically recruited in 2002–2003 via 25 maternities across Flanders. Cd, Pb, PCB congeners 118, 170, 138, 153 and 180, p,p′-DDE — a key metabolite of DDT- and hexachlorobenzene (HCB) were measured in cord blood or plasma. Cd was detected in 64% of the samples (geometric mean 0.21 µg/L cord blood). p,p′-DDE (110 ng/g plasma lipids) and Pb (14.7 µg/L blood), were measurable in nearly all samples. The individual PCB congeners could be detected in 40 to 81% of the newborns (138 + 153 + 180 = 64.4 ng/g plasma lipids). HCB (18.9 ng/g plasma lipids) and dioxin-like compounds measured by DR-CALUX® (23 pg CALUX-TEQ/g lipids) were above detection limit in more than 75% of the samples. Age and smoking habits of the mothers, did not influence the cord blood Pb and Cd levels. The organochlorines increased 4 to 9% per year of the mother's age (partial R² = 0.05 to 0.22). Mothers had 2.6% less PCBs in cord blood (partial R² = 0.02) for each unit increase in pre-pregnancy BMI. Season of delivery, breastfeeding previous children or consumption of local dairy products, were minor determinants. Up to 20% of the variability in organochlorine concentrations was explained by residence area. It was concluded that the place of birth in Flanders is an important determinant of the load of pollutants measured at the start of life. This underlines the validity of human biomonitoring on (relatively) small geographical scale.     

Predictors and long-term reproducibility of urinary phthalate metabolites in middle-aged men and women living in urban Shanghai

Phthalate esters are man-made chemicals commonly used as plasticizers and solvents, and humans may be exposed through ingestion, inhalation, and dermal absorption. Little is known about predictors of phthalate exposure, particularly in Asian countries. Because phthalates are rapidly metabolized and excreted from the body following exposure, it is important to evaluate whether phthalate metabolites measured at a single point in time can reliably rank exposures to phthalates over a period of time. We examined the concentrations and predictors of phthalate metabolite concentrations among 50 middle-aged women and 50 men from two Shanghai cohorts, enrolled in 1997–2000 and 2002–2006, respectively. We assessed the reproducibility of urinary concentrations of phthalate metabolites in three spot samples per participant taken several years apart (mean interval between first and third sample was 7.5 years [women] or 2.9 years [men]), using Spearman's rank correlation coefficients and intra-class correlation coefficients. We detected ten phthalate metabolites in at least 50% of individuals for two or more samples. Participant sex, age, menopausal status, education, income, body mass index, consumption of bottled water, recent intake of medication, and time of day of collection of the urine sample were associated with concentrations of certain phthalate metabolites. The reproducibility of an individual's urinary concentration of phthalate metabolites across several years was low, with all intra-class correlation coefficients and most Spearman rank correlation coefficients ≤ 0.3. Only mono(2-ethylhexyl) phthalate, a metabolite of di(2-ethylhexyl) phthalate, had a Spearman rank correlation coefficient ≥ 0.4 among men, suggesting moderate reproducibility. These findings suggest that a single spot urine sample is not sufficient to rank exposures to phthalates over several years in an adult urban Chinese population.