(posted 8601 days ago)James is right. It's not like millions of people are dumping these chemicals into the water supply all the time. If home photography was much much more popular then there would be a problem. Worrying about this under these circumstances is over reacting. If we really were causing harm then I'm sure environmentalists would bring it out in the open with scientific facts proving it...
I would be more worried about how your health may be getting affected if you are not being careful with these chemicals.