NCI is collaborating in Spain on an interdisciplinary hospital-based case-control study of bladder cancer. This study has evaluated the risk of bladder cancer in relation to occupational and environmental exposures, such as tobacco, air pollution, analgesics, dietary factors, urination habits, fluid intake, urinary pH and chlorination by-products in drinking water, and the effects of genetic susceptibility markers and tumor markers. Investigators used state-of-the-art methods to collect detailed exposure and genetic information. Many manuscripts from the study have been published, and additional analyses of specimens and data are underway.