Environmental Working Group - EWG.org has a site where they publish the "Dirty Dozen" and the "Clean 15." They also have a "Skin Deep" database that rates toxicity levels in personal care products.
Personal care products are a primary source of water pollution, chronic and deadly illnesses.
Most people think things like shampoo ingredients are government regulated, but all the random chemicals dumped into the catch word "fragrance" are not. They are protected by Trade Secret laws.
We might want to grow those things that are the most poisonous and/or expensive to buy. We can have yards full of buried potatoes. They can even be left there for food emergencies.