We probably going to self-destruct pretty quickly here. Let's not forget this lesson, and store some carbon for next civilization 50000 years from now, maybe they will get a clue.

"Give me a break!" - OK!

"It is hard to get effects at very low concentrations."

This is not true at all. Depending on state of your health, age etc you have various reactions and allergies to different chemical compounds, dosage has very little to do with anything if person is already sick and won't / can't tolerate certain chemical compounds. In fact certain over the counter drugs can significantly weaken people that can't tolerate them even in smallest quantities. Basically what you saying is that if i feed you poison in very small quantities for a long time then it won't affect you and you should not worry about it at all. As long as dosage is small enough it will all come out? ridiculous...

but you are right - industrial chemicals in water are equally as dangerous.

here is some more material on the topic: http://www.uas.coop/node/1095