The worst US county for life expectancy for males is McDowell County, West Virginia. It's 89.1% white. The worst for females is Perry, Kentucky. It's 97.34% white.
Counties identified in Life Expectancy in Some U.S. Counties Is No Better Than in the Third World - NationalJournal.com
Related: Facts are Cool: race and gender, now with class! notes that the poorest counties in the US are also mostly white.