Abstract  BACKGROUND: We expanded an existing cohort of workers (n = 2,588) considered highly exposed to polychlorinated biphenyls (PCBs) at two capacitor manufacturing plants to include all workers with at least 90 days of potential PCB exposure during 1939-1977 (n = 14,458). Causes of death of a priori interest included liver and rectal cancers, previously reported for the original cohort, and non-Hodgkin lymphoma (NHL), melanoma, and breast, brain, intestine, stomach, and prostate cancers, based on other studies. METHODS: We ascertained vital status of the workers through 1998, and cumulative PCB exposure was estimated using a new job exposure matrix. Analyses employed standardized mortality ratios (SMRs; U.S., state, and county referents) and Poisson regression modeling. RESULTS: Mortality from NHL, melanoma, and rectal, breast, and brain cancers were neither in excess nor associated with cumulative exposure. Mortality was not elevated for liver cancer [21 deaths; SMR 0.89; 95% confidence interval (CI), 0.55-1.36], but increased with cumulative exposure (trend p-value = 0.071). Among men, stomach cancer mortality was elevated (24 deaths; SMR 1.53; 95% CI, 0.98-2.28) and increased with cumulative exposure (trend p-value = 0.039). Among women, intestinal cancer mortality was elevated (67 deaths; SMR 1.31; 95% CI, 1.02-1.66), especially in higher cumulative exposure categories, but without a clear trend. Prostate cancer mortality, which was not elevated (34 deaths; SMR 1.04; 95% CI, 0.72-1.45), increased with cumulative exposure (trend p-value = 0.0001). CONCLUSIONS: This study corroborates previous studies showing increased liver cancer mortality, but we cannot clearly associate rectal, stomach, and intestinal cancers with PCB exposure. This is the first PCB cohort showing a strong exposure-response relationship for prostate cancer mortality.

Abstract  An Indiana capacitor-manufacturing cohort (n=3,569) was exposed to polychlorinated biphenyls (PCBs) from 1957 to 1977. The original study of mortality through 1984 found excess melanoma and brain cancer; other studies of PCB-exposed individuals have found excess non-Hodgkin lymphoma and rectal, liver, biliary tract, and gallbladder cancer. Mortality was updated through 1998. Analyses have included standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) using rates for Indiana and the United States, standardized rate ratios (SRRs), and Poisson regression rate ratios (RRs). Estimated cumulative exposure calculations used a new job-exposure matrix. Mortality overall was reduced (547 deaths; SMR, 0.81; 95% CI, 0.7-0.9). Non-Hodgkin lymphoma mortality was elevated (9 deaths; SMR, 1.23; 95% CI, 0.6-2.3). Melanoma remained in excess (9 deaths; SMR, 2.43; 95% CI, 1.1-4.6), especially in the lowest tertile of estimated cumulative exposure (5 deaths; SMR, 3.72; 95% CI, 1.2-8.7). Seven of the 12 brain cancer deaths (SMR, 1.91; 95% CI, 1.0-3.3) occurred after the original study. Brain cancer mortality increased with exposure (in the highest tertile, 5 deaths; SMR, 2.71; 95% CI, 0.9-6.3); the SRR dose-response trend was significant (p=0.016). Among those working >or= 90 days, both melanoma (8 deaths; SMR, 2.66; 95% CI, 1.1-5.2) and brain cancer (11 deaths; SMR, 2.12; 95% CI, 1.1-3.8) were elevated, especially for women: melanoma, 3 deaths (SMR, 5.99; 95% CI, 1.2-17.5); brain cancer, 3 deaths (SMR, 2.87; 95% CI, 0.6-8.4). These findings of excess melanoma and brain cancer mortality confirm results of the original study. Melanoma mortality was not associated with estimated cumulative exposure. Brain cancer mortality did not demonstrate a clear dose-response relationship with estimated cumulative exposure.

Abstract  BACKGROUND: Persistent organic pollutants (POPs), which are endocrine disruptors that accumulate in adipose tissue, can increase the risk of periodontal disease through the disturbance of the immune system. OBJECTIVE: We examined associations of background exposure to POPs with periodontal disease in the general population. DESIGN: Cross-sectional associations of concentrations of serum POPs with the prevalence of periodontal disease were investigated in 1,234 adults >= 20 years of age in the National Health and Nutrition Examination Survey 1999-2002. RESULTS: Among several POPs, organochlorine (OC) pesticides were most strongly associated with periodontal disease. Adjusted odds ratios across quintiles of OC pesticides were 1.0, 1.3, 1.7, 2.4, and 2.7 (p for trend < 0.01) for the presence in any site of clinical attachment loss >= 4 mm and 1.0, 1.7, 2.6, 3.4, and 3.7 (p for trend < 0.01) for the presence of pocket depth >= 4 mm. Polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins also showed significant positive associations with one or both definitions of periodontal disease. Results did not materially change when continuous variables of clinical attachment loss or pocket depth were used as outcomes. Although participants with periodontal disease had higher white blood cell and neutrophil counts, neutrophil counts were inversely related to OC pesticides (p for trend < 0.01). These inverse associations did not change after excluding subjects with C-reactive protein >= 3 mg/L. CONCLUSION: POPs, especially OC pesticides, were positively associated with periodontal disease, possibly through immunomodulation due to OC pesticides.

Abstract  Objective: Even though persistent organic pollutants (POPs) are well-known neurotoxicants, there is no previous study, even cross-sectional, on the association between background exposure to POPs and clinically significant developmental disorders, such as learning disability (LD) or attention deficit disorder ( ADD), among children from a general population. Design: Cross-sectional study. Setting: Study subjects were 278 children aged 12 - 15 years included in the National Health and Nutrition Examination Survey 1999 - 2000. The seven most commonly detected POPs ( each detectable in >= 20% of children: 3,39,4,49,5-pentachlorobiphenyl; 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HPCDD); 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin (OCDD); 1,2,3,4,6,7,8-heptachlorodibenzofuran (HPCDF); beta-hexachlorocyclohexane; p, p'-dichlorodiphenyltrichloroethane; and trans-nonachlor) were selected. Main results: Compared with children with non-detectable levels of POPs, adjusted prevalence ORs (95% CIs) of LD among those with detectable levels of HPCDD, OCDD or HPCDF were 2.08 (1.17 to 3.68), 2.72 (1.24 to 5.99) and 2.18 (1.15 to 4.15), respectively. For ADD, the corresponding figures were 3.41 (1.08 to 10.8), 3.33 (0.94 to 11.8) and 2.31 (0.62 to 8.63), respectively. Conclusions: Associations were observed between serum concentrations of POPs belonging to the categories of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans and the prevalence of two clinically significant development problems, LD and ADD. The nature of these associations needs to be clarified by prospective studies.

Abstract  Fifty-five present and past transformer repair workers exposed to polychlorinated biphenyls (PCBs) and 56 unexposed comparison workers were evaluated in a clinical-epidemiologic study. The groups were similar in most demographic variables. Adipose tissue lipid and serum PCBs concentrations were higher in current exposed workers (geometric means adipose 2.1 ppm, serum 12.2 ppb). Concentrations in comparison (0.6 ppm and 4.6 ppb) and previously exposed (0.83 ppm and 5.9 ppb) workers were lower. Statistically significant differences in serum albumin and lactic dehydrogenase, but not in other liver function tests, were seen between the exposed and comparison groups; however, after adjustment for confounding variables, no correlations were observed between liver function tests and either adipose or serum PCBs concentrations. Statistically significant correlation both before and after adjustment for confounding variables were seen with adipose PCBs and 24-hr urinary 17-hydroxycorticosteroid excretion and with serum PCBs and serum gamma-glutamyl transpeptidase. Both associations could reflect microsomal enzyme induction among other possibilities. No differences were seen in fasting serum triglycerides, total cholesterol, LDL, HDL or VLDL cholesterol between the two exposure groups. A statistically significant correlation between serum PCBs and serum triglycerides, total cholesterol, and VLDL cholesterol was removed by adjusting for confounding variables. No correlation was seen between adipose PCBs concentrations and any serum lipid component. Partition phenomena could account for these findings.

Abstract  Polychlorinated biphenyls (PCBs), environmental pollutants that concentrate in the fatty tissue of predatory sports fish, cross the placenta in women exposed to ordinary dietary levels. Two hundred forty-two newborn infants whose mothers consumed moderate quantities of contaminated lake fish and 71 infants whose mothers did not each such fish were examined during the immediate postpartum period. PCB exposure, measured by both contaminated fish consumption and cord serum PCB levels, predicted lower birth weight and smaller head circumference. Exposed infants were 160 to 190 gm lighter than controls, and their heads were 0.6 to 0.7 cm smaller. Head circumference was disproportionately small in relation to both birth weight and gestational age. Control analyses showed that none of these effects was attributable to any of 37 potential confounding variables, including socioeconomic status, maternal age, smoking during pregnancy, and exposure to polybrominated biphenyls. These findings are consistent with earlier reports from studies in laboratory animals.

Abstract  Clinical and experimental studies on respiratory involvement and alterations in immune status were carried out. Respiratory distress occurring in these patients has improved gradually for 14 years but still remains. Copious expectoration at an early stage of the disease may be related to the fact that a number of discrete polychlorinated biphenyls (PCBs) are distributed throughout the lung parenchyma. For accumulation in the bronchial mucosa, structural requirements and specific dose dependence of PCBs have been clearly shown; however, pathological and physiological studies have indicated that respiratory involvement in yusho is mainly small airway disease that may be caused by involvement of cellular component (Clara cells) in bronchioles and/or associated infection. Respiratory distress is often exacerbated by viral or bacterial infection. Changes in the immune status in PCB and polychlorinated dibenzofuran (PCDF) poisoning are as follows: IgA and IgM in the serum are decreased at an early stage of the disease and then return to normal; suppression of cellular immunity was reported in Taiwanese patients and some may remain in the later stages of the disease, as shown in our patients. PCDFs now appear to be the main causal agents in yusho. Rats given PCDFs showed necrosis of the Clara cells in bronchioles and marked thymus atrophy, while few such changes were noted in rats given PCBs. Therefore, further examination is needed for the difference of the toxic effects between two compounds.

Abstract  A prospective investigation of breast cancer and organochlorine (OC) exposures was undertaken in the New York University Women's Health Study. Cases (n = 148) and individually matched controls (n = 295) were identified among women whose blood had been obtained 6 months or more prior to breast cancer diagnosis. In addition, among 84 cases and 196 controls, two or more consecutive annual blood samples were available to estimate half-lives of 1,1-dichloro-2,2-bis(p-chlorophenyl) ethene (DDE) and polychlorinated biphenyls (PCBs). Cases and controls had similar levels of DDE (geometric mean, 6.95 versus 7.27 ng/ml; lipid-adjusted geometric mean, 977 versus 1100 ng/g) and PCBs (5.04 versus 4.97 ng/ml; lipid-adjusted geometric mean, 683 versus 663 ng/g). These differences remained nonsignificant when estrogen receptor status of tumors was considered. DDE and PCB half-lives did not differ in case versus control patients. In control patients, DDE and PCB half-lives were strongly correlated (r(s) = 0.71), and the half-life of DDE (but not that of PCB) was inversely correlated with body mass index (BMI), yet the blood serum levels of PCB (but not those of DDE) were correlated with BMI. We conclude that there is no evidence for an association of breast cancer risk with DDE or PCB levels in blood (based on samples collected during the period 1987-1992) nor with their elimination half-lives. However, changes in DDE and PCBs over time are influenced by metabolism, BMI, and current OC exposures, and each may affect interpretation of OC levels in risk assessment models.

Abstract  Polychlorinated biphenyl (PCB) concentrations in the blood of mothers who were occupationally exposed to PCBs in a capacitor manufacturing facility, and their children, were analyzed from 1975 to 1979. The factory terminated PCB use in 1972, and environmental PCBs were eliminated artificially. Despite this, blood PCB levels of the mothers were very high, i.e., 10-100 times higher than that of non-occupationally exposed persons. In a previous report, we discussed the relationship between breast-feeding and PCB levels in the blood. This relationship is confirmed further by the present investigation which continued during a 5-yr period. The PCB levels in blood of children were influenced greatly by the duration of breast-feeding, but showed little relationship to the PCB levels in maternal blood. The PCB exposure period of the mothers, time of birth, and age of the children were less clearly related to the PCB levels in the children. The PCB concentration in the children's blood decreased at a constant rate and was independent of their blood PCB levels. A similar result was noted for their mothers' PCB levels. A slight difference, however, was found in the rate of decrease of blood PCB levels between the mothers and children. The results of questionnaire research on the health conditions and the medical examinations for the children showed that frequency of complaints, e.g., red eye, fever, itchy skin, and carious teeth, related favorably to the duration of breast-feeding. Less severe findings, i.e., decay of nails, pigmentation, mottled enamel, carious teeth, which were typical symptoms in yusho patients, were observed in some children. They were not, however, diagnosed as having PCB poisoning inasmuch as medical treatments were unnecessary.

Abstract  An epidemiological study was made of babies born between January 1967 and April 1972 to 108 Japanese families affected by Yusho. The purpose was to find babies born to mothers who had consumed rice oil contaminated with polychlorinated-biphenyls (1336363) (PCBs). The 27 babies born during this period were divided into three groups, depending on when the mother had consumed the contaminated oil. Group 1 consisted of breast fed babies whose mothers consumed the oil during the breast feeding period. Group 2 consisted of infants whose mothers consumed the oil during their pregnancies. Group 3 consisted of babies whose mothers ingested the oil prior to pregnancy. Of the 27 babies, 22 were surveyed, the other five having moved out of the area. Two of the seven babies fed with the mother's milk contaminated with PCB were definitely diagnosed as Yusho babies, being referred to as trans-milk Yusho babies. Two of the four babies classified in Group 2, their mothers having ingested contaminated oil during pregnancy, were definitely diagnosed as Yusho, being referred to as trans-placental Yusho babies. Of the 11 remaining babies, whose mothers consumed the contaminated oil prior to pregnancy, one was diagnosed as Yusho. Seven of the remaining ten showed symptoms of Yusho, dark gray skin or pigmentation of the gingiva at birth; however, they have not been diagnosed yet. These observations suggest that human milk secreted by mothers who had consumed the contaminated oil may contain PCB in sufficient concentration to affect the babies. As none of the mothers' milk was available, determination of PCB levels in the milk was not possible. It is also suggested that the mammary glands and placenta act as excretory passages. It is recommended that the infants be kept under continuous medical observation as a follow-up and that experiments be designed to find countermeasures for the toxins in polluted mother's milk. (Japanese: English translation available)

Abstract  Background: Lead (Pb) and polychlorinated biphenyls (PCBs) are neurotoxic contaminants that have been related to impairment in response inhibition. Objectives: This study examined the neurophysiological correlates of the response inhibition deficits associated with these exposures, using event-related potentials (ERP) in a sample of school-aged Inuit children from Arctic Québec exposed through their traditional diet. Methods: In a prospective longitudinal study, we assessed 196 children (mean age = 11.3 years) on a visual Go/No-go response inhibition paradigm. Pb, PCB, and mercury (Hg) concentrations were analysed in cord and current blood samples. Hierarchical multiple regression analyses were conducted to examine the associations of contaminant levels to Go/No-go performance (mean reaction time, % Correct Go, % Correct No-go) and five ERPs (N2, P3, ERN, Pe, and Pc) after control for confounding variables. Results: Current blood Pb concentrations were associated with higher rates of false alarms and with decreased P3 amplitudes to Go and No-go trials. Current plasma PCB 153 concentrations were associated with slower reaction times and with reduced amplitudes of the Pe and Pc response-related potentials. Hg concentrations were not related to any outcome on this task but showed significant interactions with other contaminants on certain outcomes. Conclusions: These results suggest that Pb exposure during childhood impairs the child's ability to allocate the cognitive resources needed to correctly inhibit a prepotent response, resulting in increased impulsivity. By contrast, postnatal PCB exposure appears to affect processes associated with error monitoring, an aspect of behavioural regulation required to adequately adapt to the changing demands of the environment, which results in reduced task efficiency.

Abstract  BACKGROUND: The incidence of type 1 diabetes in Europe is increasing at a rate of about 3% per year and there is also an increasing incidence throughout the world. Type 1 diabetes is a complex disease caused by multiple genetic and environmental factors. Persistent organochlorine pollutants (POPs) have been suggested as a triggering factor for developing childhood type 1 diabetes. The aim of this case-control study was to assess possible impacts of in utero exposure to POPs on type 1 diabetes. METHODOLOGY/ PRINCIPAL FINDINGS: The study was performed as a case-control study within a biobank in Malmö, a city located in the Southern part of Sweden. The study included 150 cases (children who had their diagnosis mostly before 18 years of age) and 150 controls, matched for gender and day of birth. 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153) and the major DDT metabolite 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) were used as a biomarkers for POP exposure. When comparing the quartile with the highest maternal serum concentrations of PCB-153 with the other quartiles, an odds ratio (OR) of 0.73 (95% confidence interval [CI] 0.42, 1.27) was obtained. Similar results was obtained for p,p'-DDE (OR 0.56, 95% CI 0.29, 1.08). CONCLUSIONS: The hypothesis that in utero exposure to POPs will trigger the risk for developing type 1 diabetes was not supported by the results. The risk estimates did, although not statistically significant, go in the opposite direction. However, it is not reasonable to believe that exposure to POPs should protect against type 1 diabetes.

Abstract  OBJECTIVES: Endogenous and exogenous estrogens are important in the development of endometrial cancer. Several organochlorine compounds, such as o,p'-DDT, have estrogenic properties. The objective of this case-control analysis was to examine serum concentrations of organochlorine compounds and risk of endometrial cancer.

METHODS: Analyses were based on a sample of 90 endometrial cancer cases and 90 individually matched community controls from a multicenter case-control study in five geographic regions of the United States. Information on potential confounders, including menstrual and reproductive factors, cigarette smoking, diet, and weight, was obtained by interview.

RESULTS: The adjusted relative risk of endometrial cancer in the highest quartile of exposure compared with women in the lowest quartile was 0.7 (95 percent confidence interval [CI] = 0.2-2.0) for p,p'-DDE, and 0.9 for total polychlorinated biphenyls (PCBs) (CI = 0.4-2.5).

CONCLUSIONS: These findings do not support the hypothesis that organochlorine compounds are linked to the development of endometrial cancer.

Abstract  OBJECTIVES: To investigate the effect of prenatal exposure to polychlorinated biphenyls (PCBs) and dichlorodiphenyl-dichloroethylene (DDE) on weight, height and body mass index (BMI) in adult female offspring of the Michigan fisheater cohort examined between 1973 and 1991.

METHODS: 259 mothers from the Michigan fisheater cohort were studied. Prenatal exposure to PCBs and DDE was estimated by extrapolating maternal measurements to the time that the women gave birth. 213 daughters aged 20-50 years in 2000 were identified and 83% of them participated in at least one of two repeated investigations in 2001/02 (n = 151) and 2006/07 (n = 129). To assess the effect of prenatal PCB and DDE exposure on anthropometric measurements, generalised estimating equations nested for repeated measurements (2001/02 and 2006/07) and for sharing the same mother were used. We controlled for maternal height and BMI and for daughters' age, birth weight, having been breastfed and number of pregnancies.

RESULTS: Maternal height and BMI were significant predictors of the daughters' height, weight and BMI. Low birth weight (<2500 g) was significantly associated with reduced adult offspring weight and BMI. The weight and BMI of adult offspring were statistically significantly associated with the extrapolated prenatal DDE levels of their mothers. Controlling for confounders and compared to maternal DDE levels of <1.503 microg/l, offspring BMI was increased by 1.65 when prenatal DDE levels were 1.503-2.9 microg/l and by 2.88 if levels were >2.9 microg/l. Prenatal PCB levels showed no effect.

CONCLUSION: Prenatal exposure to the oestrogenic endocrine-disrupting chemical DDE may contribute to the obesity epidemic in women.

Abstract  Background: Polybrominated biphenyl (PBB), a brominated flame retardant, was accidently mixed into animal feed in Michigan (1973–1974) resulting in human exposure through consumption of contaminated meat, milk and eggs. Beginning in 1976 individuals who consumed contaminated products were enrolled in the Michigan Long-Term PBB Study. This cohort presents a unique opportunity to study the association between parental exposures to PBB and offspring sex ratio. Methods: We identified offspring of female PBB cohort participants (born 1975–1988) and obtained electronic birth records for those born in the state of Michigan. We linked this information to parental serum PBB and PCB concentrations collected at enrollment into the cohort. We modeled the odds of a male birth with generalized estimating equations accounting for the nonindependence of siblings born to the same parents. We explored potential confounders: parental age and education at offspring's birth, parental body mass index at cohort enrollment, birth order, gestational age and year of offspring's birth. Results: The overall proportion of male offspring among 865 live births to cohort mothers was 0.542. This was higher than the national male proportion of 0.514 (binomial test: p = 0.10). When both parents were in the cohort (n = 300), we found increased odds of a male birth with combined parents' enrollment PBB exposure ≥ the median concentrations (3 μg/L for mothers; 6 μg/ L for fathers) compared to combined parents' PBB exposure < the median concentrations (AOR = 1.43, 95% CI: 0.89–2.29), although this did not reach statistical significance. In addition, there was a suggestion of increased odds of a male birth for combined parents' enrollment PCB exposure ≥ the median concentrations (6 μg/L for mothers; 8 μg/L for fathers) compared to combined parents' enrollment PCB exposure < the median concentrations (AOR = 1.53, 95% CI: 0.93–2.52). Conclusion: This study adds to the body of literature on secondary sex ratio and exposure to environmental contaminants. In this population, combined parental exposure to PBBs or PCBs increased the odds of a male birth. Further research is needed to corroborate these findings and shed light on the biological mechanisms by which these types of chemicals may influence the secondary sex ratio.

Abstract  BACKGROUND: Fish from the Great Lakes are contaminated with polychlorinated biphenyls, which have been found to have several adverse reproductive effects. Several environmental contaminants have been found to alter the sex ratio of offspring at birth, but the evidence of such an effect of polychlorinated biphenyls has been inconsistent.

METHODS: We examined parental serum polychlorinated biphenyl concentration in relation to the sex ratio of 173 children of mothers and 208 children of fathers from the Great Lakes region of the United States between 1970 and 1995. We calculated odds ratios for a male child using logistic regression and generalized estimating equations with adjustment for the year of birth of the child, maternal and paternal age, the mother's parity at the child's birth, and whether the child had an older brother.

RESULTS: The adjusted odds ratio for having a male child among mothers in the highest quintile of serum polychlorinated biphenyl concentration was 0.18 (95% CI: 0.06-0.59) compared to mothers in the lowest quintile. Treating exposure as a continuous variable, the adjusted odds ratio for having a male child was 0.54 per unit increase in the natural log of maternal serum polychlorinated biphenyl concentration (95% CI: 0.33-0.89). There was little evidence of an association with paternal exposure. We found no association between either maternal or paternal serum dichlorodiphenyl-dichloroethene concentration and the sex ratio.

CONCLUSIONS: These findings suggest that maternal exposure to polychlorinated biphenyls may decrease the sex ratio of offspring. These data add to the growing body of evidence that exposure to particular chemicals can alter the sex ratio at birth.

Abstract  Objectives To estimate the internal PCB level in Swedish workers specialised in PCB abatement in buildings and to measure possible effects of PCB on thyroid function and aspects of the immune system. Methods Thirty six of 40 eligible workers (90%) removing old elastic sealants containing PCB and 33 control construction workers provided blood samples for determination of 19 PCB congeners and some other organochlorine compounds (hexachlorobenzene and p,p?-DDE), thyroid function hormones and a set of cytokines. The PCB exposed group was reinvestigated after 10 months for a trend assessment. Results The sum of 19 PCB congeners in blood plasma from the occupationally PCB-exposed group was twice the level in the controls (geometric mean 580 vs. 260 ng/g lipid; P < 0.001), and there was also some difference in p,p?-DDE between the groups while the lipid-adjusted hexachlorobenzene levels were of the same magnitude. No statistically significant increase in overall PCB levels was observed in the abatement workers at follow-up and some congeners even declined. Thyroid function was not associated with PCB exposure at the current levels and this applied also to the cytokines investigated. Conclusions Swedish workers removing old elastic sealants with PCB have a higher internal PCB load than unexposed colleague construction workers, tentatively secondary to historical exposure. A system of protective measures seemed to be efficient since no further increase was noted after a longish period of additional exposure. There was no evidence of thyroid function or immune system involvement, as expressed by a set of cytokines, at the low PCB levels recorded.

Abstract  Previous studies have suggested that exposure to polychlorinated biphenyls (PCBs) may alter thyroid function, but data on effects of PCB exposure on other endogenous hormones has been lacking. The current study is ancillary to a larger investigation of the effects of Great Lakes fish consumption on PCBs and reproductive function. In the current study we examine associations of PCBs, 1,1-bis (4-chlorophenyl) -2,2-dichloroethene (DDE) , and fish consumption with thyroid and steroid hormones in 178 men and PCBs, DDE, and fish consumption with thyroid hormones in 51 women from the original study. Serum PCB level and consumption of Great Lakes fish are associated with significantly lower levels of thyroxine (T4) and free thyroxine index (FTI) in women and with significantly lower levels of T4 in men. Fish consumption, but not PCB level, is significantly and inversely associated with triiodothyronine (T3) in men. Results for thyroid-stimulating hormone (TSH) are inconsistent. Among men, there are significant inverse associations of both PCB and fish consumption with sex hormone-binding globulin (SHBG) -bound testosterone, but no association with SHBG or free testosterone. There are no significant overall associations of PCB, DDE, or fish consumption with estrone sulfate, follicle-stimulating hormone, luteinizing hormone, or dehydroepiandrosterone sulfate. The results of this study are consistent with previous studies showing effects of fish consumption and PCB exposure on thyroid hormones and suggest that PCBs may also decrease steroid binding to SHBG. Elucidation of specific mechanisms must await future investigations.

Abstract  Although lead (Pb) exposure has been identified as an important risk factor in child behavioral development, less is known regarding the relation between child behavior and exposure to polychlorinated biphenyls (PCBs) and mercury (Hg). Inuit children are particularly exposed to these chemicals and the aim of this study was to investigate the association between prenatal and postnatal exposure to Pb, PCBs, Hg and several aspects of behavioral function in Inuit preschoolers. The sample consisted of one hundred and ten 5-year-old Inuit children from Arctic Quebec. An umbilical cord blood sample was used to document prenatal exposure to Pb, PCBs and Hg. Child blood samples were collected at age 5 and the same contaminants were measured. A modified version of the Infant Behavior Rating Scale from the Bayley Scales of Infant Development-II was used to assess child behavior through examiners' ratings. Furthermore, attention, activity and emotional outcomes were assessed through behavioral coding of video recordings taken during fine motor testing. Pb exposure during childhood was associated with examiners ratings of greater impulsivity, irritability and with coding of observed inattention. Prenatal exposure to PCB 153 correlated with the examiners ratings of increased state of unhappiness and anxiety during the testing session, which was corroborated from video coding since cord PCB 153 was related to fewer manifestations of positive affects. No association was found with Hg exposure. These data corroborated those from previous Pb cohort studies and revealed an association between prenatal PCBs exposure and emotional outcomes in preschoolers.

Abstract  BACKGROUND: Prior studies have reported an increased risk of diabetes related to polychlorinated biphenyl (PCB) exposure. No study has yet investigated whether polybrominated biphenyls (PBBs), which are similar in chemical structure, increase the incidence of diabetes. METHODS: The Michigan PBB cohort was established in 1976 and surveyed again in 1991-1993 and in 2001. PBB and PCB serum levels were measured from blood collected at enrollment. To determine the incidence of adult-onset diabetes, we analyzed cohort members without diabetes at enrollment, ages 20 years and older, with known PBB and PCB levels, who participated in at least 1 follow-up survey (n = 1384). Using Poisson regression, we determined the incidence density ratio (IDR) of diabetes for different serum levels of PBB and PCB, controlling for age, body mass index, smoking, and alcohol consumption at enrollment. RESULTS: Analyzing 25 years of follow-up data, we did not find that higher PBB serum levels were a risk factor for the incidence of diabetes mellitus. However, in women, but not in men, higher PCB serum levels were associated with increased incidence of diabetes (IDR = 2.33; 95% confidence interval = 1.25-4.34 in the highest PCB group compared with the lowest). In both men and women, overweight and obesity increased the diabetes incidence. CONCLUSIONS: We found no association between PBB serum levels and diabetes incidence. In women, there was a positive linear association of diabetes incidence with PCB serum levels at enrollment. This finding is in agreement with 2 prior studies indicating a higher relative risk of diabetes in PCB-exposed women.

Abstract  OBJECTIVES: Because of well known association between the exposure to persistent organochlorinated pollutants (POPs) and impaired immune system, it was attempted to check possible coincidence of nuclear and thyroperoxidase antibodies with the levels of major POPs.

METHODS: Antinuclear antibodies. (ANA) were estimated by indirect immunofluorescence test using Hep2- cells and thyroperoxidase antibodies (TPOab) by electrochemiluminiscent immunoassay in the cohort of 253 adults (82 males and 171 females) aged 21-75 years, among them 144 (46 males and 98 females) from the area polluted (POLL) by polychlorinated biphenyls (PCB) and 109 (36 males and 73 females) from the area of background pollutrion (BCGR). In the same cohort fifteen congeners of PCB and also total DDE (2,2'-bis(4-chlorophenyl)-1,1-dichloroethylene) and hexachlorobenzene (HCB) were estimated by high resolution gas chromatography/mass spectrometry.

RESULTS: Prevalence of ANA only was significantly higher in POLL than in BCGR in males (p < 0.001) and females (p < 0.001) and the same was true for the prevalence of TPOab in males (p < 0.05) and females (p < 0.01) from POLL. In addition, also the prevalence of coincident ANA+TPOab in males (p < 0.001) and females (p < 0.05) was significantly higher in POLL. In a total of 253 pooled males and females from both areas and stratified in terms of PCB level quintiles. The prevalence of ANA in the 4th and 5th quintile of each among three pollutants (PCB, DDE and HCB) was significantly higher (p < 0.01 or < 0.001) and showed the parallel increase with the level of all pollutants.

CONCLUSIONS: Significantly increased prevalence of ANA either only or in coincidence with TPOab was found related to increasing level of PCB, DDE and HCB.

Abstract  PURPOSE: To test whether environmental pollutants could affect fertility in humans.

METHODS: 31 women and 16 men from Tanzania and 21 couples from Germany were included (n = 89). Pesticides and polychlorinated biphenyls were measured in serum, follicular fluid or seminal plasma by gaschromatography and related to sperm quality and pregnancy rates.

RESULTS: Higher concentrations of DDT+DDE and dieldrin in Tanzania and higher concentrations of PCBs in Germany and in men were detected. All compounds showed higher concentrations in serum and lowest concentrations in seminal plasma. A lower pregnancy rate in German women with high serum concentrations of DDT+DDE was observed. The toxins had no impact on sperm quality.

CONCLUSIONS: The distribution of toxins between agricultural and industrial countries is different. Seminal plasma seems to be inert against chemicals. In patients with high serum concentrations of DDT and DDE pregnancy rates were impaired.

Abstract  BACKGROUND: Inconsistent results have been found in previous human studies on male reproductive toxicity of persistent organochlorine pollutants. The majority of studies have been conducted among selected populations of infertility clients or among occupational cohorts including a limited number of participants.

METHODS: We conducted a cross-sectional study of semen quality and serum concentration of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) among 763 men. We included men from all regions in Greenland (n = 194), fishermen from Sweden (n = 185), inhabitants of the city of Kharkiv, Ukraine (n = 195), and inhabitants of the city of Warsaw, Poland (n = 189). Blood samples were analyzed for CB-153 and p,p'-DDE using gas chromatography-mass spectrometry and adjusted for serum lipids.

RESULTS: Sperm concentration was not impaired with increasing serum CB-153 or p,p'-DDE levels in any of the separate groups or overall. Similarly, the proportion of morphologically normal sperm was not associated with either CB-153 or p,p'-DDE blood concentration. However, sperm motility was inversely related to CB-153 concentration in Greenland and the Swedish fishermen population. Across all 4 regions, the sperm motility decreased on average by 3.6% (95% confidence interval = 1.7% to 5.6%) per one-unit increase in the log of blood CB-153 (ng/g lipid). The concentration of p,p'-DDE was negatively associated with sperm motility in the Greenlandic population and in the compiled dataset.

CONCLUSION: Adult exposure to persistent organochlorine pollutants within the ranges observed in the present study is not likely to cause reduction in sperm concentration or morphology. However, higher exposure may be associated with impaired sperm motility.

Abstract  Fact-finding surveys of workers occupationally exposed to polychlorinated biphenyls (PCBs) in the production of silk thread or of paint were carried out. Some of the workers showed higher PCB levels in the plasma than typical Yusho patients. Gas chromatographic patterns of their PCBs were shown to match the pattern of the PCBs to which they had been exposed. Levels of polychlorinated quaterphenyls in their blood were lower than 0.02 ppb. Medical findings were slight compared with typical Yusho patients. From these results, the differences in contamination with PCBs and relevant compounds and in health status between these workers and Yusho patients are discussed.