Editorial Comment.

It is known that chronic exposure to environmental carcinogens is a risk factor for bladder tumor development.[1] While the study is interesting, the authors have not addressed certain practical issues. Minerals, such as chromium, selenium, and zinc are present in many popular supplements and are sold over the counter.[2] Even manganese supplements are available. Consumption of these dietary supplements in the form of pills, sold over the counter, is common even in India.[3] However, a study from Taiwan noticed higher urinary levels of zinc and selenium in bladder cancer cases than in controls.[4] Similarly, some people drink water from copper utensils.[5] However, a Chinese study evaluating 81 patients showed that the urinary calcium, zinc, and serum copper levels in patients to be significantly higher (P < 0.05) than those of the control group.[6] It is evident that the issue needs to be resolved as it has practical implications.