At least some consumer goods have similar limits, e.g. maximum amount of arsenic permitted in apple juice. Of course, whenever people find out about these limits, they lose their shit... "Why is any arsenic ok? OMG! The evil government is trying to poison us!"
The person in charge of a mass spectrometer (Thermo Element 2) at a local college likes to toy with his students by running tests on their commercial bottled water during a lab demonstration. This particular instrument can pick up minute traces of uranium, lead, and the like (on the order of fg/L IIRC).
At the end of the demonstration, the trash can is full of discarded water bottles.
