A laboratory test of 22 types of lettuce purchased at Northern California supermarkets found that four were contaminated with perchlorate, a toxic rocket-fuel ingredient that has polluted the Colorado River, the source of the water used to grow most of the nation's winter vegetables.
At the same time, a Bush administration proposal known as the Readiness and Range Preservation Initiative is making its way through the GOP-controlled Congress. Among other things, it would exempt military bases from laws requiring the cleanup of toxic substances associated with munitions and other explosives, which include perchlorate.