Serum Polychlorinated Biphenyls Research Articles

Polychlorinated Biphenyl (PCB) Exposure and Diabetes: Results from the Anniston Community Health Survey

Background: Polychlorinated biphenyls (PCBs) manufactured in Anniston, Alabama, from 1929 to 1971 caused significant environmental contamination. The Anniston population remains one of the most highly exposed in the world.Objectives: Reports of increased diabetes in PCB-exposed populations led us to examine possible associations in Anniston residents.Methods: Volunteers (n = 774) from a cross-sectional study of randomly selected households and adults who completed the Anniston Community Health Survey also underwent measurements of height, weight, fasting glucose, lipid, and PCB congener levels and verification of medications. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the relationships between PCBs and diabetes, adjusting for diabetes risk factors. Participants with prediabetes were excluded from the logistic regression analyses.Results: Participants were 47% African American, 70% female, with a mean age of 54.8 years. The prevalence of diabetes was 27% in the study population, corresponding to an estimated prevalence of 16% for Anniston overall; the PCB body burden of 35 major congeners ranged from 0.11 to 170.42 ppb, wet weight. The adjusted OR comparing the prevalence of diabetes in the fifth versus first quintile of serum PCB was 2.78 (95% CI: 1.00, 7.73), with similar associations estimated for second through fourth quintiles. In participants < 55 years of age, the adjusted OR for diabetes for the highest versus lowest quintile was 4.78 (95% CI: 1.11, 20.6), whereas in those ≥ 55 years of age, we observed no significant associations with PCBs. Elevated diabetes prevalence was observed with a 1 SD increase in log PCB levels in women (OR = 1.52; 95% CI: 1.01, 2.28); a decreased prevalence was observed in men (OR = 0.68; 95% CI: 0.33, 1.41).Conclusions: We observed significant associations between elevated PCB levels and diabetes mostly due to associations in women and in individuals < 55 years of age.

A Methodological Approach to Assessing the Health Impact of Environmental Chemical Mixtures: PCBs and Hypertension in the National Health and Nutrition Examination Survey

We describe an approach to examine the association between exposure to chemical mixtures and a health outcome, using as our case study polychlorinated biphenyls (PCBs) and hypertension. The association between serum PCB and hypertension among participants in the 1999–2004 National Health and Nutrition Examination Survey was examined. First, unconditional multivariate logistic regression was used to estimate odds ratios and associated 95% confidence intervals. Next, correlation and multicollinearity among PCB congeners was evaluated, and clustering analyses performed to determine groups of related congeners. Finally, a weighted sum was constructed to represent the relative importance of each congener in relation to hypertension risk. PCB serum concentrations varied by demographic characteristics, and were on average higher among those with hypertension. Logistic regression results showed mixed findings by congener and class. Further analyses identified groupings of correlated PCBs. Using a weighted sum approach to equalize different ranges and potencies, PCBs 66, 101, 118, 128 and 187 were significantly associated with increased risk of hypertension. Epidemiologic data were used to demonstrate an approach to evaluating the association between a complex environmental exposure and health outcome. The complexity of analyzing a large number of related exposures, where each may have different potency and range, are addressed in the context of the association between hypertension risk and exposure to PCBs.

Assessment of exposure to PCB 153 from breast feeding and normal food intake in individual children using a system approach model

Investigators have typically relied on a single or few discrete time points as measures of polychlorinated biphenyl (PCB) body burden, however health effects are more likely to be the result of integrative exposure in time, optionally expressed as an area under the time curve (AUC) of PCB serum concentration. Using data from a subgroup of 93 infants from a birth cohort in eastern Slovakia—a region highly polluted by PCBs—we fit a system type model, customized to our longitudinal measures of serum PCB concentrations in cord, 6, 16, and 45 month blood specimens. The most abundant congener, PCB 153, was chosen for modeling purposes. In addition to currently used methods of exposure assessment, our approach estimates a concentration time profile for each subject, taking into account mean residence time of PCB 153 molecules in the body, duration of breast feeding, hypothetical PCB 153 concentration in steady-state without breast feeding and alternately without normal food intake. Hypothetical PCB 153 concentration in steady-state without normal food intake correlates with AUC ( r = 0.84, p < 0.001) as well as with duration of breast feeding ( r = 0.64, p < 0.001). It makes possible to determine each subject’s exposure profile expressed as AUC of PCBs serum concentration with a minimum model parameters. PCB body burden in most infants was strongly associated with duration of breast feeding in most, but not all children, was apparent from model output.

Dioxin and Polychlorinated Biphenyl Concentrations in Mother's Serum and the Timing of Pubertal Onset in Sons

Animal studies have demonstrated that timing of pubertal onset can be altered by prenatal exposure to dioxins or polychlorinated biphenyls (PCBs), but studies of human populations have been quite limited. We assessed the association between maternal serum concentrations of dioxins and PCBs and the sons' age of pubertal onset in a prospective cohort of 489 mother-son pairs from Chapaevsk, Russia, a town contaminated with these chemicals during past industrial activity. The boys were recruited at ages 8 to 9 years, and 4 years of annual follow-up data were included in the analysis. Serum samples were collected at enrollment from both mothers and sons for measurement of dioxin and PCB concentrations using high-resolution mass spectrometry. The sons' pubertal onset--defined as pubertal stage 2 or higher for genitalia (G) or pubic hair (P), or testicular volume >3 mL--was assessed annually by the same physician. In multivariate Cox models, elevated maternal serum PCBs were associated with earlier pubertal onset defined by stage G2 or higher (4th quartile hazard ratio = 1.7 [95% confidence interval = 1.1- 2.5]), but not for stage P2 or higher or for testicular volume >3 mL. Maternal serum concentrations of dioxin toxic equivalents were not consistently associated with the sons' pubertal onset, although a dose-related delay in pubertal onset (only for G2 or higher) was seen among boys who breast-fed for 6 months or more. Maternal PCB serum concentrations measured 8 or 9 years after sons' births--which may reflect sons' prenatal and early-life exposures--were associated with acceleration in some, but not all, measures of pubertal onset.

Highlights of recent studies and future plans for the French human biomonitoring (HBM) programme

This manuscript presents highlights of recent studies and perspectives from the French human biomonitoring (HBM) programme. Until recently, HBM studies focused on specific populations or pollutants to gain a better understanding of exposure to environmental chemicals, to help regulators reduce environmental exposure and to monitor existing policies on specific concerns. Highlights of recent multicentre biomonitoring studies with specific population or pollutant focus are given. These French HBM studies have been implemented to know: (1) the influence of living near an incinerator on serum dioxin and polychlorinated biphenyl (PCB) levels, (2) the influence of consuming river fish contaminated by PCBs on serum PCBs of fishermen, and (3) the evolution of blood lead levels in children from 1 to 6 years old since 1995. Special emphasis is placed on the use of an integrated (HBM coupled with nutrition and health studies), multipollutant approach. This approach has been initiated in France with a recent national population-based biomonitoring survey, the Etude Nationale Nutrition Santé (ENNS; French Nutrition and Health Survey). This survey will provide the first reference distribution for 42 biomarkers in the French population. The current national HBM strategy will build upon the ENNS and include a national survey of people aged between 6 and 74 years complemented for the neonatal period and childhood by the Etude Longitudinale Française depuis l'Enfance (ELFE; French longitudinal study of children). France also contributes to the harmonization of HBM activities in Europe through participation in European HBM projects.

A META-ANALYSIS OF CORD SERUM CONCENTRATIONS OF PCB AND BIRTH WEIGHT

Background and Aims Exposure to high concentrations of persistent organochlorines may cause fetal toxicity, but evidence regarding reproductive effects at lower concentrations is limited. Within the framework of the EC ENRIECO and OBELIX projects, we examined the hypothesis that polychlorinated biphenyls (PCBs) impair fetal growth. Methods We used maternal and cord blood and breast milk samples in 7.990 women enrolled in twelve European birth cohorts from 1990-2008, and re-expressed all measurements as cord serum estimates of PCB 153. Using identical variable definitions, we performed linear regression analyses of birth weight on cord serum estimates of PCB 153 for each cohort. Analyses were adjusted for gestational age and a priori selected covariates. Summary estimates were obtained by meta-analysis. Results The median concentration of cord serum PCB 153 was 134 ng/L (range of medians 20–485). In all cohorts except the two smallest, birth weight decreased with increasing cord serum concentration of PCB 153 after adjustment for potential confounders. The meta-analysis across all cohorts indicated a birth weight decline of 150 g (95% CI 50-250 g) per one µg/L increase of PCB 153, which is close to the range of exposure levels across the cohorts. The results did not change substantially in any of the sensitivity analyses in all or subsets of the cohorts. These included control for weight gain during pregnancy, restriction to full term babies, control for lipid concentration in serum and models based upon quadratic and loglinear transformations of exposure measures. Finally, we found no indication of effect modification of gender, tobacco smoking or concentration of the DDT metabolite p,p´-DDE. Conclusions The findings suggest that low-level exposure to PCB or correlated exposures in Europe impairs human fetal growth.

Incidence of thyroid disease following exposure to polybrominated biphenyls and polychlorinated biphenyls, Michigan, 1974–2006

Thyroid hormones, which influence body metabolism and development, could be affected by persistent organic pollutants. We sought to examine the relationship between polybrominated biphenyls (PBBs) and polychlorinated biphenyls (PCBs) and thyroid disease. We employed incidence density sampling to perform a nested case control analysis of the Michigan Long-Term PBB Cohort. Cohort members (n=3333) were exposed to PBBs through contaminated cattle feed in 1973–1974 and to PCBs through daily life. Those with detectable serum PBB and PCB concentrations at enrollment were categorized into tertiles of PBB and PCB exposure. Case-patients were cohort members answering “Yes” to “Has a healthcare provider ever told you that you had a thyroid problem?” during follow-up interviews; control-patients were cohort members answering “No”. We used odds ratios (OR) with 95% confidence intervals (CI) to compare odds of thyroid disease by PBB and PCB exposure and by various risk factors. Total cumulative thyroid disease incidence after 33years was 13.9% among women and 2.6% among men. After adjusting for body mass index, we found no statistically significant differences in odds of any type of thyroid disease among women or men with elevated PBB or PCB exposure. Compared to control-patients, women with thyroid disease had increased odds of being overweight/obese (OR=2.82, 95% CI: 1.94–4.11) and developing infertility (OR=1.71, 95% CI: 1.08–2.69), diabetes (OR=1.61, 95% CI: 1.04–2.51), or arthritis (OR=1.71, 95% CI: 1.18–2.50) during follow-up. Additional research should explore potential associations between PBBs/PCBs and thyroid disease among children exposed in utero.

Polychlorinated biphenyls (PCBs) in indoor air and in serum among older residents of upper Hudson River communities

A study was conducted to evaluate the association between PCBs in residential indoor air and in the serum of older, long time residents of three upper Hudson River communities. Samples of indoor air and of serum were collected from 170 persons 55 to 74 years of age, and analyzed for PCBs using glass capillary gas chromatography. After adjusting for age, BMI, cigarette smoking, and Hudson River fish consumption with multiple linear regression analysis, the results indicated statistically significant associations between concentrations in indoor air and serum for PCB-28, a lightly chlorinated congener common in air that accumulates in serum, and PCB-105. Duration of exposure was an important factor, since among persons who had lived in their home for 39 years or more, 11 of the 12 most commonly detected congeners were significantly correlated, as was their sum (∑ PCB). Significant associations between indoor air and serum PCB concentrations also were more likely when collected in cooler months and if the two samples were collected within 20 d of each other. The study is among the first to indicate that PCB concentrations characteristic of residential indoor air are associated with a detectable increase in body burden.

Associations of polychlorinated biphenyl exposure and endogenous hormones with diabetes in post-menopausal women previously employed at a capacitor manufacturing plant

There is an increasing body of literature showing associations of organochlorine exposure with risk of diabetes and insulin resistance. Some studies suggest that associations differ by gender and that diabetes risk, in turn, may be affected by endogenous steroid hormones. This report examines the relationships of serum PCBs and endogenous hormones with history of diabetes in a cohort of persons previously employed at a capacitor manufacturing plant. A total of 118 women were post-menopausal with complete data, of whom 93 were not using steroid hormones in 1996, at the time of examination, which included a survey of exposure and medical history, height, weight and collection of blood and urine for measurements of lipids, liver function, hematologic markers and endogenous hormones. This analysis examines relationships of serum polychlorinated biphenyls (PCBs), work exposure and endogenous hormones with self-reported history of diabetes after control for potential confounders. All PCB exposure groups were significantly related to history of diabetes, but not to insulin resistance as measured by the homeostatic model assessment of insulin resistance (HOMA-IR) in non-diabetics. Diabetes was also independently and inversely associated with follicle stimulating hormone (FSH), dehydroepiandrosterone sulfate (DHEAS) and triiodothyronine (T3) uptake. HOMA-IR was positively associated with body mass index (BMI) and C-reactive protein (CRP) and inversely associated with sex hormone binding globulin (SHBG) and T3 uptake after control for PCB exposure. Possible biologic mechanisms are discussed. This study confirms previous reports relating PCB exposure to diabetes and suggests possible hormonal pathways deserving further exploration.

Obesity and Persistent Organic Pollutants: Possible Obesogenic Effect of Organochlorine Pesticides and Polychlorinated Biphenyls

Persistent organic pollutants (POPs) are endocrine-disrupting chemicals associated with the development of the metabolic syndrome and type 2 diabetes. In humans, little is known about their role in the potential origin of obesity. This study aims to assess the associations between serum levels of POPs and the prevalence of obesity in a cohort of obese and lean adult men and women. POP serum samples were investigated cross-sectionally in 98 obese and 47 lean participants, aged ≥18 years. Serum samples were analyzed for the presence of polychlorinated biphenyl (PCB) congeners 153, 138, 180, and 170 and for the organochlorine pesticides, dichloro-diphenyl-dichloroethylene (pp-DDE), and β-hexachlorocyclohexane (βHCH). We established a significant negative correlation between BMI, waist, fat mass percentage, total and subcutaneous abdominal adipose tissue, and serum levels of PCB 153, 180, 170, and the sumPCBs. For βHCH, we demonstrated a positive correlation with BMI, waist, fat mass percentage, and total and subcutaneous abdominal adipose tissue. PCBs 180, 170, and the sum of PCBs correlated significantly negative with homeostasis model assessment for insulin resistance (HOMA(IR)). βHCH correlated significantly positively with HOMA(IR). A strong correlation was established between all POP serum levels and age. We established a positive relationship between high serum levels of βHCH and BMI and HOMA(IR), whereas serum PCB levels were inversely correlated with BMI and HOMA(IR). Combined, these results suggest that the diabetogenic effect of low-dose exposure to POPs might be more complicated than a simple obesogenic effect.

Serum Concentrations of Polychlorinated Biphenyls in Relation to in Vitro Fertilization Outcomes

Background: Human exposure to polychlorinated biphenyls (PCBs) remains widespread. PCBs have been associated with adverse reproductive health outcomes including reduced fecundability and increased risk of pregnancy loss, although the human data remain largely inconclusive.Objective: Our goal was to explore the relationship between serum PCB concentrations and early pregnancy loss among a large cohort of women undergoing in vitro fertilization (IVF) between 1994 and 2003.Methods: Concentrations of 57 PCB congeners were measured in serum samples collected during 827 IVF/intracytoplasmic sperm injection cycles from 765 women. Joint statistical models that accommodate multiple outcomes and multiple cycles per woman were used to assess the relationship between serum PCB quartiles and implantation failure, chemical pregnancies (human chorionic gonadotropin level > 5.0 mIU/mL) that did not result in clinical pregnancy, or spontaneous abortion, while also adjusting for confounders.Results: PCB-153 was the congener present in the highest concentration (median, 46.2 ng/g lipid). Increasing quartiles of PCB-153 and the sum of all measured PCB congeners (ΣPCBs) were associated with significantly elevated dose-dependent odds of failed implantation. Adjusted odds ratios (95% confidence interval) for highest versus lowest quartile were 2.0 (1.2–3.4) for PCB-153 and 1.7 (1.0–2.9) for ΣPCBs. There were suggestive trends for increased odds of implantation failure for PCB-118 and cytochrome P450–inducing congeners (p-values for trend = 0.06). No statistically significant associations between PCBs and chemical pregnancy or spontaneous abortion were found.Conclusions: Serum PCB concentrations at levels similar to the U.S. general population were associated with failed implantation among women undergoing IVF. These findings may help explain previous reports of reduced fecundability among women exposed to PCBs.

Serum Dioxins and Polychlorinated Biphenyls Are Associated With Growth Among Russian Boys

We evaluated the associations of serum dioxins and polychlorinated biphenyls (PCBs) with longitudinally assessed growth measurements among peripubertal Russian boys. A total of 499 boys from Chapaevsk, Russia, aged 8 to 9 years were enrolled in the study from 2003 to 2005 and were followed prospectively for 3 years. Blood samples were collected and physical examinations were conducted at entry and repeated at annual study visits. Multivariate mixed-effects regression models for repeated measures were used to examine the associations of serum dioxins and PCBs with longitudinal measurements of BMI, height, and height velocity. Serum dioxin (total 2005 toxic equivalency [TEQ] median: 21.1 pg/g lipid) and PCBs (median sum of PCBs: 250 ng/g lipid) were measured in 468 boys. At study entry and during 3 years of follow-up, >50% of the boys had age-adjusted BMI and height z scores within 1 SD of World Health Organization-standardized mean values for age. Boys in the highest exposure quintile of the sum of dioxin and PCB concentrations and total TEQs had a significant decrease in mean BMI z scores of 0.67 for dioxins and TEQs and 1.04 for PCBs, compared with boys in the lowest exposure quintile. Comparison of the highest versus the lowest quintile revealed that higher serum PCB concentrations were associated with significantly lower height z scores (mean z-score decrease: 0.41) and height velocity (mean decrease: 0.19 cm/year) after 3 years of follow-up. Our findings suggest that exposures to dioxins and PCBs are associated with reduced growth during the peripubertal period and may compromise adult body mass, stature, and health.

Prenatal Exposure to PCBs and OCPs and Neurodevelopment of Newborn: Shanghai Study

PP-31-079 Background/Aims: Research found that prenatal exposure to polychlorinated biphenyls (PCBs) and organochlorine pesticide (OCPs) can affect infant growth and neurodevelopment. But we have not known PCBs and OCPs prenatal exposure levels in Shanghai and whether or not they affect infant health at these levels. This study is to investigate the prenatal exposure levels of PCBs and OCPs to identify the exposing high-risk factors in Shanghai, and to evaluate the effect of the PCBs and OCPs prenatal exposure on the growth and neurodevelopment of newborn infants. Methods: A total of 200 mother–infant pairs were enrolled between October 2008 and September 2009 in Shanghai. General information and risk factors were obtained by questionnaire. Birth weight, length, and head circumference were obtained from medical records. Neonatal neurodevelopment was determined by neonatal behavioral neurological assessment. Cord blood samples were collected during delivery, and PCB and OCP levels in cord serum were determined by gas chromatography-electron capture detector. Results: Among the 21 investigated PCBs and 20 investigated OCPs, p,p'-DDE, HCB, β-HCH are predominant pollutants found in cord serum. The detection rates were 91.4%, 87.8%, 76.6% and the median (range) were about 0.46 (0.34–23.01) μg/L, 0.66 (0.12–2.31) μg/L, 0.42 (0.2–6.81) μg/L, respectively. p,p'-DDE was positively correlated with mothers' age, occupation, education level, and egg and meat consumption frequency. β-HCH was positively correlated with mother's occupation and shrimp consumption frequency. The association between HCB and these factors were not found. We did not find any association between p,p'-DDE, HCB, β-HCH levels and infant birth weight, length, and head circumference. The association between p,p'-DDE, HCB, β-HCH and the results of neonatal behavioral neurological assessment were also not found. But we found HCB was negative when correlated with hand grip and β-HCH was negative when correlated with hand stretch. The detection rates of PCBs ranged from 0% to 38%; related results are not given because of low detection rate. Conclusion: In this research, we found that the predominant contaminant were p,p'-DDE, HCB, β-HCH, and food maybe their major resource. We did not find effects on infant health. This research provided useful information about related study and further research.

Incidence of Thyroid Disease Following Exposure to Polybrominated Biphenyls and Polychlorinated Biphenyls, Michigan, 1974–2006

O-29B4-2 Background/Aims: Although the thyroid gland plays a crucial metabolic role throughout life, the effects of persistent chemicals on the thyroid have received limited attention. Of particular interest are persistent organic pollutants, which are used in many consumer products and are increasing in environmental concentration. Our objective was to examine the relationship between serum polybrominated biphenyl (PBB) and polychlorinated biphenyl (PCB) concentrations and thyroid disease incidence. Methods: We employed incidence density sampling to perform a nested case control analysis of the Michigan Long-term PBB Cohort. Cohort members (n = 3333) were exposed to PBBs following the unintentional 1973 contamination of cattle feed and to PCBs through diet and the environment. Serum PBB and PCB concentrations were measured at enrollment; cases were cohort members who answered “Yes” to “Has a healthcare provider ever told you that you had a thyroid problem?” during follow-up interviews. We calculated odds ratios (OR) with 95% confidence intervals (CI) and assessed body mass index (BMI), smoking, and prior pregnancy for confounding and effect modification. Results: Total cumulative thyroid disease incidence after 33 years was 13.9% among females and 2.6% among males. After adjusting for BMI, there were no statistically significant differences in thyroid disease incidence by PBB or PCB exposure among females. There was a trend towards increased thyroid disease incidence among males exposed to PBBs or PCBs, but this was statistically insignificant. Compared to controls, women with a thyroid disease had increased odds of being overweight/obese (OR = 2.82; 95% CI: 1.94, 4.11) and having infertility (OR = 1.71; 95% CI: 1.08, 2.69), diabetes (OR = 1.61; 95% CI: 1.04, 2.51), or arthritis (OR = 1.71; 95% CI: 1.18, 2.50). Conclusion: The Michigan Long-term PBB Cohort is and will continue to be valuable in assessing the public health impacts of PBB and PCB exposures. Additional research is warranted to further explore potential associations between PBBs/PCBs and adverse thyroid disease in males.

Relationship of polychlorinated biphenyls with type 2 diabetes and hypertension

Diabetes and hypertension are important contributors to morbidity and mortality worldwide. Both of these conditions are caused by some combination of genetic and environmental factors which may include exposure to persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs). Studies have shown an association between elevated serum PCBs and the metabolic syndrome, insulin sensitivity and insulin secretion. Cross-sectional studies have shown associations between diabetes or hypertension and certain PCB congeners or classes, while those same studies show no association between diabetes or hypertension and several other PCB congeners. In animal and human cell studies, various PCBs and dioxins appear to alter glucose and insulin metabolism. These studies specifically show effects on the glucose transporter (GLUT-4) gene and protein; insulin-like growth factor binding protein-1 (IGFBP-1); nuclear transcription factor kappa B (NFκB); tumor necrosis factor alpha (TNF-α); and insulin production. There are a few longitudinal studies examining the association of diabetes or hypertension and PCBs with no consensus conclusion. Some longitudinal studies have found there to be an association, others have not and a gender difference has also been noted. Prospective studies are needed to determine if PCBs and other POPs contribute to development of diabetes and hypertension.

Background levels of polychlorinated biphenyls in the population of the Canary Islands (Spain)

Polychlorinated biphenyls (PCBs) are persistent and toxic compounds that have been detected in human serum or tissues worldwide. The objective of our study was to determine serum PCB levels in a representative sample of the general population of the Spanish Archipelago of the Canary Islands (607 serum samples from subjects aged between 6 and 75 years) in order to establish the main causes of this contamination and to evaluate the potential risks posed by these chemicals on the population through the use of toxicity equivalence to dioxins (TEQs). PCB congeners (28, 52, 77, 81, 101, 105, 114, 118, 123, 126, 138, 153, 156, 157, 167, 169, 180, and 189) were measured by gas chromatography–mass spectrometry (GC/MS). Our results showed that PCB residues were found in 76% of serum samples analyzed, with the congeners 153 and 180 being the most frequently detected and having the highest median values (21.8 and 6.7 ng/g lipid, respectively). Serum levels of non-dioxin-like PCBs increased with age, body mass index (BMI), urban habitat, and smoking. The median concentration of the sum of PCBs considered as markers of environmental contamination by these chemicals (M-PCBs) was 46.4 ng/g lipid. Levels of the sum of dioxin-like PCBs (DL-PCBs) were 48.5 ng/g lipid in the 95th percentile, and were also positively associated with age. As a consequence, age seemed to be positively associated with TEQs levels, reaching values as high as 58.6 pg/g lipid in the serum samples from oldest people. Our results indicate that the inhabitants of the Canary Archipelago show levels of PCB contamination lower than other populations present on the Spanish mainland, as well as many populations from developed countries. Nevertheless, as these compounds may induce adverse health effects even at very low doses, our findings should be considered by local Public Health authorities in order to establish measures for diminishing the exposure of the population of these islands to PCBs.

Blood pressure and hypertension in relation to levels of serum polychlorinated biphenyls in residents of Anniston, Alabama

To determine risk factors for elevated blood pressure and hypertension in residents of Anniston, Alabama who live near a plant that manufactured polychlorinated biphenyls (PCBs). A total of 758 Anniston residents had multiple measurements of blood pressure, provided information on demographic factors, medications, smoking, and exercise, and provided blood samples for determination of PCBs and total serum lipid. Rates of hypertension increased significantly (P < 0.05) with age and concentration of serum PCBs and were higher in African-Americans (n = 351) than in whites (n = 407). Hypertension also increased with BMI, but was not related to total serum lipid, sex, smoking, or exercise. Among 394 persons not on antihypertensive medication, linear regression analysis demonstrated a significant positive relation between serum PCB level and both systolic and diastolic blood pressure. After adjustment for potentially confounding variables, logistic regression gave odds ratios for the highest to lowest tertiles of total serum PCBs that exceeded 3.5 for both systolic and diastolic hypertension. When analyzed by quintiles of PCBs, the highest odds ratio was in the third quintile, suggesting a low dose effect. In individuals not on antihypertensive medication, serum PCB levels were significantly associated with prevalence of hypertension. Significant positive associations were also observed between PCB concentrations and systolic and diastolic blood pressure even in normotensive ranges. The strength of the relationships between PCB exposure and both hypertension and blood pressure suggests that PCB exposure may be an important contributing factor in regulation of blood pressure.

Predictors of Serum Dioxin, Furan, and PCB Concentrations among Women from Chapaevsk, Russia

Dioxins, furans, and polychlorinated biphenyls (PCBs) are persistent and bioaccumulative toxic chemicals that are ubiquitous in the environment. We assessed predictors of their serum concentrations among women living in a Russian town contaminated by past industrial activity. Blood samples from 446 mothers aged 23-52 years were collected between 2003-2005 as part of the Russian Children's Study. Serum dioxin, furan, and PCB concentrations were quantified using high-resolution gas chromatography-mass spectrometry. Potential determinants of exposure were collected through interviews. Multivariate linear regression models were used to identify predictors of serum concentrations and toxic equivalencies (TEQs). The median total PCB concentrations and total TEQs were 260 ng/g lipid and 25 pg TEQ/g lipid, respectively. In multivariate analyses, both total PCB concentrations and total TEQs increased significantly with age, residential proximity to a local chemical plant, duration of local farming, and consumption of local beef. Both decreased with longer breastfeeding, recent increases in body mass index, and later blood draw date. These demographic and lifestyle predictors showed generally similar associations with the various measures of serum dioxins, furans, and PCBs.

Allergy and Sensitization during Childhood Associated with Prenatal and Lactational Exposure to Marine Pollutants

BackgroundBreast-feeding may affect the risk of developing allergy during childhood and may also cause exposure to immunotoxicants, such as polychlorinated biphenyls (PCBs), which are of concern as marine pollutants in the Faroe Islands and the Arctic region.ObjectivesThe objective was to assess whether sensitization and development of allergic disease is associated with duration of breast-feeding and prenatal or postnatal exposures to PCBs and methylmercury.MethodsA cohort of 656 singleton births was formed in the Faroe Islands during 1999–2001. Duration of breast-feeding and history of asthma and atopic dermatitis were recorded at clinical examinations at 5 and 7 years of age. PCB and mercury concentrations were determined in blood samples obtained at parturition and at follow-up. Serum from 464 children (71%) at 7 years of age was analyzed for total immunoglobulin E (IgE) and grass-specific IgE.ResultsThe total IgE concentration in serum at 7 years of age was positively associated both with the concomitant serum PCB concentration and with the duration of breast-feeding. However, the effect only of the latter was substantially attenuated in a multivariate analysis. A raised grass-specific IgE concentration compatible with sensitization was positively associated with the duration of breast-feeding and inversely associated with prenatal methylmercury exposure. However, a history of asthma or atopic dermatitis was not associated with the duration of breast-feeding, although children with atopic dermatitis had lower prenatal PCB exposures than did nonallergic children.ConclusionsThese findings suggest that developmental exposure to immunotoxicants may both increase and decrease the risk of allergic disease and that associations between breast-feeding and subsequent allergic disease in children may, at least in part, reflect lactational exposure to immunotoxic food contaminants.

PCBs in School—Persistent Chemicals, Persistent Problems

The issue of polychlorinated biphenyls (PCB) exposures resulting from occupancy of PCB-contaminated buildings is not new, but the contribution of building materials to that contamination is largely unrecognized. A rapidly emerging base of evidence shows that PCBs can be widely found in caulking and paint in masonry buildings constructed or renovated from about 1950 to the late 1970s. These materials can cause extensive PCB contamination of the building interiors and surrounding soil, and people who teach, live, or attend school in these buildings can have elevated serum PCB levels. The potential risk associated with this source of PCB exposure is not known; however, it is worth noting that the specific PCB congeners found at high levels in the building environments, and in biological samples from the occupants, include some that are suspected of being potent neurotoxins. The U. S. Environmental Protection Agency (EPA) is moving to address this issue in schools; however, the costs of remediating contaminated buildings will pose a formidable obstacle to most school districts.