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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, [beta]-hexachlorocyclohexane, mirex, p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), and p,p'-dichlorodiphenyltrichloroethane. Adjusted odds ratios (ORs) and their associated 95% confidence intervals (Cls) 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% CI = 1.23 to 2.38, [P.sub. trend] = .0002) and of twO chlordane components, cis-nonachlor (Q4 vs Q1, OR = 1.56, 95% CI = 1.11 to 2.18, [P.trend = .009) and trans-nonachlor (Q4 vs Q1, OR = 1.46, 95% CI = 1.07 to 2.00, [P.sub.trend] = .026). Seminoma risk was statistically significantly associated with p,p'-DDE (Q4 vs Q1, OR = 1.91, 95% CI = 1.22 to 2.99, [P.sub. trend] = .0008), cis-nonachlor (Q4 vs Q1, OR = 1.93, 95% CI = 1.27 to 2.93, [P.sub. trend] = .0045), trans-nonachlor (Q4 vs Q1, OR = 1.72, 95% CI = 1.11 to 2.67, [P.sub. trend] = .033), and a chlordane metabolite, oxychlordane (Q4 vs Q1, OR = 1.64, 95% CI = 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% CI = 1.10 to 2.42, [P.sub. trend] = .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.

Background: 1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) exposure has been demonstrated to cause liver tumors in laboratory rodents. DDT's persistent metabolite and environmental degradation product, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), has also been associated with liver tumors in laboratory animals. Whether DDT and DDE are associated with hepatocarcinogenesis in humans is not clear. Methods: We carried out a nested case-control study among the participants of the Nutritional Intervention Trials in Linxian, China. The case group included 168 individuals who developed liver cancer during the trials, and the control group included 385 individuals frequency-matched on age and sex who were alive and well at the end of the study. Serum concentrations of DDT and DDE were measured by gas chromatography--mass spectrometry. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariable analysis. Results: In multivariable-adjusted models, the risk of developing liver cancer increased with increased serum DDT concentration (OR for quintile 1 versus quintile 5 = 3.8, 95% CI = 1.7 to 8.6, [P.sub.trend] = .0024). In contrast, there was no statistically significant association between liver cancer and serum DDE concentration. The association between high serum DDT concentration and liver cancer was stronger among individuals with DDE concentrations below the median value (odds ratio for tertile 3 versus tertile 1 = 3.55, 95% CI = 1.45 to 8.74) than those with concentrations above the median (OR = 1.70, 95% CI = 0.97 to 2.98). A calculation of crude liver cancer risk found that there would be 26 liver cancers per 100000 persons per year in the lowest quintile of DDT exposure versus 46 liver cancers per 100000 persons per year in the highest quintile of DDT exposure. Conclusions: DDT may be a risk factor for liver cancer, particularly among persons with lower DDE concentrations. Risk may be particularly increased among persons exposed directly to DDT (resulting in a higher ratio of DDT to DDE) or, alternatively, risk may be associated with individual ability to metabolize DDT to DDE.

Mercury is used widely for gold extraction in French Guiana and throughout the entire Amazon basin. To evaluate contamination among the general population, the authors chose individuals who attended 13 health centers and maternity hospitals dispersed geographically across the territory and served Guiana's different populations. Five hundred individuals (109 pregnant women, 255 'other' adults, and 136 children) who received care at one of the centers were selected randomly for this study. Each individual answered a questionnaire and provided a hair sample. The authors determined mercury in hair with atomic absorption spectrometry. The following mean levels of mercury were observed: 1.6 [micro]g/g (95% confidence interval [CI] = 1.3, 1.9) among pregnant women; 3.4 [micro]/g (95% CI = 3.0, 3.9) among other adults; and 2.5 [micro]/g (95% CI = 2.1, 3.0) among children. Diet factors contributed the most to mercury levels, especially consumption of freshwater fish (mean = 6.7 [micro]/g for individuals who ate fish more than 5 times/wk) and livers from game. Other factors, including age, dental amalgams, use of skin-lightening cosmetics, and residence near a gold-mining community, did not contribute significantly to mercury levels. Overall, 12% of the samples contained mercury levels in excess of 10 [micro]/g, but in some Amerindian communities up to 79% of the children had hair mercury levels that exceeded 10 [micro]/g. The results of this study indicated that (a) diet played a predominant role in total mercury burden, and (b) in some communities, mercury contamination exceeded safe levels., PRODUCTION of gold in French Guiana started in the 1850s. Production decreased after World War II, but recently gold-mining activities have increased. Over time, an estimated 200 tons of gold [...]

The authors conducted a survey during 1992 to evaluate blood levels of lead and mercury in Inuit adults of Nunavik (Arctic Quebec, Canada). Blood samples obtained from 492 participants (209 males and 283 females; mean age = 35 yr) were analyzed for lead and total mercury; mean (geometric) concentrations were 0.42 [micro]mol/l (range = 0.04-2.28 [micro]mol/l) and 79.6 nmol/l (range = 4-560 nmol/l), respectively. Concentrations of omega-3 fatty acid in plasma phospholipids--a biomarker of marine food consumption--were correlated with mercury (r = .56, p [is less than] .001) and, to a lesser extent, with blood lead levels (r = .31, p [is less than] .001). Analyses of variance further revealed that smoking, age, and consumption of waterfowl were associated with lead concentrations ([r.sup.2] = .30, p [is less than] .001), whereas age and consumption of seal and beluga whale were related to total mercury levels ([r.sup.2] = .30, p [is less than] .001). A significant proportion of reproductive-age women had lead and mercury concentrations that exceeded those that have been reportedly associated with subtle neurodevelopmental deficits in other populations., MERCURY AND LEAD are widespread environmental contaminants that originate from both anthropogenic (e.g., mining, smelting, fossil fuel burning, waste incineration) and natural (e.g., local geology, volcanoes, degassing in aquatic environments) [...]

The authors evaluated lead exposure of Canadians (Montreal) who fished the nearby St. Lawrence River. From screening interviews conducted with 1,118 fishers on-site during the winter and fall of 1996, the authors selected 60 Montrealers who consumed at least one sportfish meal per week and 72 who consumed less than one sportfIsh meal per week. Fishers at the higher level of sportfish consumption had elevated blood lead concentrations, compared with fishers who ate little sportfish (geometric mean = 57.4 [micro]g/l vs. 48.2 [micro]g/l, respectively; p [is less than] .05). This result was surprising inasmuch as fish is not considered a significant source of lead. In addition to sportfish consumption, age, sex, occupation, smoking, and waterfowl consumption also showed independent associations with blood lead levels. Among frequent (i.e., [is greater than or equal to] 1 meal/wk) consumers of sportfish, ingestion of waterfowl was associated with higher blood lead levels (geometric mean = 69.4 [micro]g/l vs. 51.8 [micro]g/l, respectively; p [is less than] .05); this association was not present for infrequent consumers. In multivariate analysis, the association of higher blood lead levels with sportfish consumption could be accounted for in large part by waterfowl consumption among frequent consumers of sportfish., ALTHOUGH FRESHWATER FISH contains little lead, tests of consumers of Great Lakes sportfish have shown higher than expected levels of blood lead.[1,2] In a recent study of contaminant exposure among [...]