there was a big dust up a few years ago when it turned out perchlorate was winding up in lettuce.
the problem was that the perchlorate facility, which is around the BMI complex in nevada, is a massively polluted pile of EPA superfund-ish nightmare.
on top of that, the private companies responsible for the pollution were able to shed themselves pf the environmental cleanup costs by shaving off subsidaries and then declaring bankruptcy. Carl Icahn is a master at this type of thing. so the government is the only one left to clean up this stuff and it cant get the money.
(of course the govt can pay a trillion dollars to invade iraq and spy on your google searches...)