Selenium availability in Texas: possible clinical significance.

In light of recent reports that have indicated that selenium is an essential micronutrient and possible natural cancer inhibitor, data on the geographic distributions of selenium in Texas were gathered and compared with the distribution of age-adjusted cancer mortality rates. We considered concentrations of selenium measured in ground and surface water to be indicators of its presence in rocks, soil, and locally grown crops. Texas water sources were found to be poor in selenium, except for the Panhandle and the West Texas regions, where soil consists of erosion products from the selenium-rich Rocky Mountains. In general, lower cancer mortality was observed for the selenium-rich regions of Texas compared with cancer mortality for the selenium-poor regions. Even though the risks from cancer-provoking factors also differed geographically, the observed pattern was sufficiently suggestive to warrant further attention to selenium.