Trace element levels in drinking water and the incidence of colorectal cancer

We determined the levels of 15 elements in drinking mater from 34 mater tre atment plants in Aomori Prefecture and studied how element levels relate to colorectal cancer incidence by district. Colorectal cancer incidence was c alculated from the data of Aomori Colorectal Cancer Registry. Multiple regr ession analysis was performed by using age-adjusted incidences of rectal ca ncer and colon cancer by gender as object variables and each element level as an explanatory variable. The standardized partial regression coefficient was significant in gold (p<0.01), magnesium (p < 0.01), selenium (p <0.01) and tin (p<0.05) for age-adjusted rectal cancer incidence in men as object ive variable; in gold (p <0.05), calcium (p<0.01) and phosphorus (p<0.01) w ith age-adjusted colon cancer incidence in men as the objective variable; a nd in sodium (p<0.05), phosphorus (p<0.05), tin (p<0.05) and strontium (p<0 .01) with age-adjusted colon cancer incidence in women as the objective var iable. These results confirm the need to further study trace elements in dr inking water and food, and relationship to colorectal carcinogenesis.