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The article discusses a research study which examined the association between polychlorinated biphenyls (PCBs) levels in the plasma and the risk of cutaneous malignant melanoma (CMM). The study found that CMM risk is strongly associated with the levels of non-dioxin-line PCBs and several PCB congeners, metabolites or organochlorine pesticides in the plasma. The study suggested that other environmental factors, aside from ultraviolet radiation (UV), could play a role in the development of CMM.

Background Exposure to endocrine-disrupting chemicals, such as persistent organochlorine pesticides, has been suggested to increase the risk of testicular germ cell tumors (TGCTs). Methods To study the relationship of POP exposure to TGCT risk, prediagnostic serum samples from 754 case subjects and 928 control subjects enrolled in the Servicemen's Testicular Tumor Environmental and Endocrine Determinants Study were analyzed for cis-nonachlor, trans-nonachlor, oxychlordane, total chlordanes, β-hexachlorocyclohexane, mirex, p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE), and p,p′-dichlorodiphenyltrichloroethane. Adjusted odds ratios (ORs) and their associated 95% confidence intervals (CIs) for the risk of TGCT overall and for the histological subgroups, seminoma and nonseminoma, were estimated using multivariable logistic regression. All statistical tests were two-sided. Results TGCT risk was statistically significantly associated with higher plasma levels of p,p′-DDE (for highest quartile [Q4] vs lowest quartile [Q1], OR = 1.71, 95% Cl = 1.23 to 2.38, Ptrend = .0002) and of two chlordane components, cis-nonachlor (Q4 vs Q1, OR = 1.56, 95% Cl = 1.11 to 2.18, Ptrend = .009) and trans-nonachlor (Q4 vs Q1, OR = 1.46, 95% Cl = 1.07 to 2.00, Ptrend = .026). Seminoma risk was statistically significantly associated with p,p′-DDE (Q4 vs Q1, OR = 1.91, 95% Cl = 1.22 to 2.99, Ptrend = .0008), cis-nonachlor (Q4 vs Q1, OR = 1.93, 95% Cl = 1.27 to 2.93, Ptrend = .0045), trans-nonachlor (Q4 vs Q1, OR = 1.72, 95% Cl = 1.11 to 2.67, Ptrend = .033), and a chlordane metabolite, oxychlordane (Q4 vs Q1, OR = 1.64, 95% Cl = 1.04 to 2.60, Ptrend = .048), whereas nonseminoma risk showed a statistically significant association with p,p′-DDE only (Q4 vs Q1, OR = 1.63, 95% Cl = 1.10 to 2.42, Ptrend = .0044). Conclusions Increased exposure to p,p′-DDE may be associated with the risk of both seminomatous and nonseminomatous TGCTs, whereas exposure to chlordane compounds and metabolites may be associated with the risk of seminoma. Because evidence suggests that TGCT is initiated in very early life, it is possible that exposure to these persistent organic pesticides during fetal life or via breast feeding may increase the risk of TGCT in young men. [ABSTRACT FROM AUTHOR]

OBJECTIVE: We set out to assess whether environmental prenatal exposure to polychlorinated biphenyls (PCBs) is associated with incidence of acute respiratory infections in preschool Inuit children. STUDY DESIGN: We reviewed the medical charts of 343 children from 0 to 5 years of age and evaluated the associations between PCB-153 concentration in umbilical cord plasma and the incidence rates of acute otitis media (AOM) and of upper and lower respiratory tract infections (URTIs and LRTIs, respectively). RESULTS: The incidence rates of AOM and LRTIs were positively associated with prenatal exposure to PCBs. Compared with children in the first quartile of exposure (least exposed), children in fourth quartile (most exposed) had rate ratios of 1.25 (p < 0.001) and 1.40 (p < 0.001) for AOM and LRTIs, respectively. There was no association between prenatal PCB exposure and incidence rate of URTIs or hospitalization. CONCLUSION: Prenatal exposure to PCBs could be responsible for a significant portion of respiratory infections in children of this population. [ABSTRACT FROM AUTHOR]

Examines the effects of the organochlorine o,p'-dichlorodiphenyldichloroethane (o,p'-DDD) on the cortisol stress response in rainbow trout, Onchorhynchus mykiss, in a dose-response study in vivo. Effect of treatment with o,p'-DDD on weight gain, hematocrit and gonado- or hepatosomatic index.

The authors analyzed the relation between lactation history, organochlorine serum levels–in particular, 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE)–and the risk of breast cancer within a subsample from a larger breast cancer case-control study conducted among women living in Mexico City, Mexico, between 1990 and 1995. From the original study, they selected a random sample of 260 subjects (1:1 case/control ratio). Analysis was restricted to 120 cases and 126 controls who had given birth to at least one child and had complete information on all key variables. Serum DDE levels were higher among cases (mean = 3.84 µg/g lipids, standard deviation = 5.98) than among controls (mean = 2.51 µg/g lipids, standard deviation = 1.97). After adjustment for age, age at menarche, duration of lactation, Quetelet index, and serum DDT levels, serum DDE levels were positively related to the risk of breast cancer (adjusted odds ratio (OR)Q1−Q2 = 1.24, 95% confidence interval (CI): 0.50, 3.06; ORQ1−Q3 = 2.31, 95% CI: 0.92, 5.86; ORQ1−Q4 = 3.81, 95% CI: 1.14, 12.80; test of trend, p = 0.02). The increased risk associated with higher serum DDE levels was more apparent among postmenopausal women (ORQ1−Q4 = 5.26, 95% CI: 0.80, 34.30; test of trend p = 0.03). A longer period of lactation was associated with a slightly decreased risk of breast cancer independently of serum DDE levels (OR = 0.91, 95% CI: 0.85, 0.99 change in risk per 10 months of lactation). Serum DDT level was not related to the risk of breast cancer. The data suggest that high levels of exposure to DDE may increase women's risk of breast cancer, particularly among postmenopausal women. Am J Epidemiol 2000;152:363–70. [ABSTRACT FROM PUBLISHER]

Objectives. This study documented the concentration of polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethylene (DDE) in the breast milk of women from Quebec, Canada, and assessed the impact of various sociodemographic and lifestyle factors on these levels. Methods. From 1988 to 1990, milk samples were obtained from 536 Quebec women and analyzed for seven PCB congeners and p,p'-DDE. Information was obtained on subjects' physical, sociodemographic, and lifestyle characteristics. Results. Mean concentrations were 0.52 mg/kg lipids (95% confidence interval [CI] = 0.50, 0.54) and 0.34 mg/kg lipids (95% CI = 0.32, 0.35) for PCBs (Aroclor 1260) and DDE, respectively. Age and history of breast-feeding showed statistically significant correlations with PCB and DDE concentrations. Conclusions. Concentrations of PCBs and DDE measured in this study are at the lower end of the concentration range recently reported for women living in industrialized countries. The modulating factors identified here should be considered when conducting studies on organochlorine exposure and disease. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To investigate the effects of low level maternal and paternal persistent contaminant exposures on fecundability among couples from the general population. Methods: About 41 couples having their first pregnancy completed questionnaires and provided blood samples for analysis of metals, organochlorine pesticides, and polychorinated biphenyls. Associations of personal consumption and contaminant measures for mothers, fathers, and couples overall were analyzed through fecundability odds ratios (fOR, probability of pregnancy per month in more versus less exposed) in multivariable analyses. Findings: Couples with higher reported caffeine consumption (couple consumption ≥111drinks/month, fOR 0.25, 95% CI, 0.10, 0.63) and higher mercury concentrations in maternal blood (>1.2μg/L or 0.24ppm in hair, fOR 0.22, 95% CI, 0.07, 0.72) had lower fecundability, after adjustment for intercourse frequency. Conclusion: Reduced fecundability at levels below the mercury reference dose warrants further research and prudent reduction in persistent toxic substances exposure among women and men of reproductive age. [Copyright &y& Elsevier]