A population-based case-control study of bladder cancer and drinking water disinfection methods was conducted during 1990-1991 in Colorado. Surface water in Colorado has historically been disinfected with chlorine (chlorination) or with a combination of chlorine and ammonia (chloramination). A total of 327 histologically verified bladder cancer cases were frequency matched by age and sex to 261 other-cancer controls. Subjects were interviewed by telephone about residential and water source histories. This information was linked to data from water utility and Colorado Department of Health records to create a drinking water exposure profile. After adjustment for cigarette smoking, tap water and coffee consumption, and medical history factors by logistic regression, years of exposure to chlorinated surface water were significantly associated with risk for bladder cancer (p = 0.0007). The odds ratio for bladder cancer increased for longer durations of exposure to a level of 1.8 (95% confidence interval 1.1-2.9) for more than 30 years of exposure to chlorinated surface water compared with no exposure. The increased bladder cancer risk was similar for males and females and for nonsmokers and smokers. Levels of total trihalomethanes, nitrates, and residual chlorine were not associated with bladder cancer risk after controlling for years of exposure to chlorinated water.

No abstract

Certain nitrosatable drugs may be associated with increased risk of infant sagittal/lambdoid craniosynostosis. A possible mechanism related to ischaemia/reperfusion injury is suggested.

Fourteen of 23 female members of a church group experienced an acute self-limited illness characterized by chills, fever, chest pain, cough, and nausea, consistent with the diagnosis of Pontiac fever. All 14 affected women had used a whirlpool located in the women's locker room during a racquetball party. Legionella pneumophila serogroup 6 was isolated from the women's whirlpool. Nine of 14 cases showed a seroconversion to heat-fixed antigen prepared from the L pneumophila serogroup 6 isolate. Aerosol size studies show that the whirlpool aerator produced water droplets small enough to travel deep into the tracheobronchial tree but large enough to transport L pneumophila. This outbreak demonstrated that Pontiac fever may be associated with L pneumophila serogroup 6, that whirlpools can serve as a reservoir for these organisms, and that seroconversion can occur in the absence of illness.

Antenatal maternal high-altitude exposure and smoking are associated with increased risk of infant craniosynostosis, perhaps through generation of intermittent hypoxaemia.