Individuals who drink large quantities of fluids every day are at a greater risk for the development of bladder cancer than those who consume less. Chlorinated tap water may be a contributing factor, a University at Buffalo research group has found.
Results of the study, published in Archives of Environmental Health, show a twofold to fourfold greater bladder cancer risk in subjects who drank more than 14 cups of fluid a day than in individuals who drank less than seven cups daily.
Breaking down consumption into tap and non-tap sources of liquid, the results suggest that tap water is an independent risk factor for bladder cancer.
The study, led by John E. Vena, Ph.D., associate professor of social and preventive medicine at the university, supports findings from previous research conducted in the United States, Denmark, and Germany that showed a relationship between bladder cancer and fluid intake and from another study showing a tap water-bladder cancer association.
Most of the study group had used chlorinated public water 90 percent of their lives.
"Chlorine reacts with a host of cancer precursor chemicals, including manmade chemicals from industrial and municipal waste water or runoff and naturally occurring organic substances to produce chlorinated compounds," Dr. Vena said. "Trihalomethanes are the most commonly occurring organics found in drinking water and appear in the highest concentrations. These compounds are toxic and carcinogenic to animals in high doses."
The Great Lakes Basin, one of the largest fresh sources of drinking water in the world and the source of tap water in this study, has been plagued with toxic chemical pollution, he noted.