I don't know who told you this but it is incorrect. We've had the capacity (via gc/ms) to measure contaminants down to 5ppm for decades. We can now even measure them in many cases down to parts per trillion.
You just admitted that what I said was true. They could only measure to 5 ppm "for decades," which means they couldn't measure parts per billion.
How fucking stupid are you?
There is nothing dubious about the fact that benzene causes cancer at low concentrations. It is well documented. in the scientific literature. It isn't a matter of if benzene causes cancer. Benzene CAUSES cancer. It is a documented fact. And by the way, benzene isn't banned. It is one of the most widely used chemicals around. It is even in your gasoline.
Sorry, but it's not documented. Whenever the EPA does tests to determine whether a substance is carcinogenic, it gives large doses of the substance to test mice. If the mice develop cancer, then the EPA sets some safe limit that might be a millions times lower than the amount given to the test mice. This procedure is based on a theory that if large doses are dangerous, then small doses are dangerous in proportion. This theory has been proven to be wrong in numerous cases.
One thing scientists never do is say some substance cause cancer no matter what the dose. Only morons like you do that.
Furthermore, where did I claim Benzene was banned?