I met a nurse that said one of her family members lived in a small housing development where almost everyone got terminal brain cancer. A certain company that you've heard of handled hazardous materials next door and offered to do the testing in the development. Surprise, no contamination found. And they made it clear that if you implicate them, you'll be contacted by their sizable legal department.
Everyone affected was either dead or bankrupt from paying their family's medical bills. No lawsuits against the company.