A new report published in the November 20 issue of the Journal of the National Cancer Institute reveals that exposure to high levels of arsenic may contribute to more aggressive tumors in patients with bladder cancer. In a study conducted by Lee E. Moore, Ph.D., of the National Cancer Institute and several colleagues, over 120 patients with bladder tumors who had been exposed to arsenic in drinking water were examined. Researchers discovered that chromosomal alterations in the bladder tumor DNA of the subjects were much higher in those exposed to high levels of arsenic. According to researchers, elevated chromosomal changes in tumors may result in increased deaths.