In the late1970 in the U.S. Lead was banned from Gasoline, and paint, amongst other things. While Atmospheric Lead levels were reduced, the Lead didn't just disappear, it just settled into the soil, and accumulated in other places. Lead was and is a common ingredient in many household and industrial products much of the time it's inclusion is either unknown or ignored. It is one of the poisons that effects Everybody - Rich or poor.
Things like this accumulate at the top of the food chain - That is generally people.
There is no cure.

du-pont put the lead in fuel..... wonder how much money they made from it.... & i wonder what it will cost us & the planet