I don't worry bout water. I don't know how the water is in the U.S., but I drink tap and bottled water. The bottled water I heard form an investigative report, comes from tap water anyway.
Just face it - we live in a dirty world and there are a lot of pollutants in many things. There's no escaping it.
Believe it or not, lobster and crabs are crustaceans and are a part of the arthropod family, which include caterpillars, cockroaches, and spiders!