Pre-Crisis Lex once cured cancer, and Post-Crisis/New 52 has cured his sister's paralysis. I'm willing to bet he could do it if he could stop thinking about Superman for five seconds.
I've figured it out by myself. Stop bad agricultural practices, stop eating filters like crab, catfish, lobsters. Stop eating dogs, snakes, cats, rabbit, which have natural parasites that protect them from the environment. If you have to eat meat, stick with chicken, beef, and fish that have scales. If there are countries that practice poor agriculture, the rest of the world should stop trade with them immediately.