No abstract

Monochloramine reduced colonization in building hot water systems.

Increasing rates of cryptorchidism and hypospadias in human populations may be caused by exogenous environmental agents. We conducted a case–control study of serum levels of p,p′-dichlorodiphenyltrichloroethane (DDT) and its major metabolite, p,p′-dichlorodiphenyldichloroethylene (DDE), and cryptorchidism and hypospadias in the Child Health and Development Study, a longitudinal cohort of pregnancies that occurred between 1959 and 1967, a period when DDT was produced and used in the United States. Serum was available from the mothers of 75 male children born with cryptorchidism, 66 with hypospadias, and 4 with both conditions. We randomly selected 283 controls from the cohort of women whose male babies were born without either of these conditions. Overall, we observed no statistically significant relationships or trends between outcomes and serum measures. After adjusting for maternal race, triglyceride level, and cholesterol level, compared with boys whose mothers had serum DDE levels < 27.0 ng/mL, boys whose mothers had serum DDE levels ≥61.0 ng/mL had odds ratios of 1.34 [95% confidence interval (CI), 0.51–3.48] for cryptorchidism and 1.18 (95% CI, 0.46–3.02) for hypospadias. For DDT, compared with boys whose mothers had serum DDT levels < 10.0 ng/mL, boys whose mothers had serum DDT levels ≥20.0 ng/mL had adjusted odds ratios of 1.01 (95% CI, 0.44–2.28) for cryptorchidism and 0.79 (95% CI, 0.33–1.89) for hypospadias. This study does not support an association of DDT or DDE and hypospadias or cryptorchidism.

BACKGROUND: Obesity may influence several physiologic processes involved in cataract formation such as oxidative stress, glycosylation and osmotic stress. OBJECTIVE: To examine the association between increased body mass index (BMI) and the incidence of cataract extraction. DESIGN AND SETTING: The Nurses' Health Study and the Health Professionals Follow-up Study, both prospective cohort studies of US women and men. SUBJECTS: A total of 87 682 women and 45 549 men aged 45 y and older who did not have diagnosed cataract or cancer at baseline (1980 for women, 1986 for men). MEASUREMENTS: Cataract extractions occurring between baseline and 1996, confirmed by medical records. RESULTS: During 16 y of follow-up in the women, and 10 y in the men, (1 097 997 person-y), 4430 incident cases were documented. Compared to participants with BMI less than 23 kg=m 2 , those with BMI greater than or equal to 30 kg=m 2 had 36% higher risk of any type of cataract (pooled multivariate relative risk (RR), 1.36; 95% CI, 1.23 -1.49) after adjusting for smoking, age and lutein=zeaxanthin intake. The association was strongest for posterior subcapsular (PSC) cataract (pooled multivariate RR, 1.99; 95% CI, 1.55 -2.55). With adjustment for diabetes, the RR of obesity associated with posterior subcapsular cataract was 1.68 (95% CI, 1.30 -2.17). Obesity was not significantly associated with nuclear cataract. CONCLUSION: Obesity increases the risk of developing cataract overall, and of PSC cataract in particular; the etiology of PSC cataract may be mediated at least in part by glucose intolerance and insulin resistance, even in the absence of clinical diabetes.