In the USA alcohol was prohibited in the 1920s, and there was a knocking problems with gas engines going over a certain speed that needed to be fixed. They tried different additives until they found lead works.<p>People got sick on the exhaust but the industry covered it up. It wasn&#x27;t until later that it was discovered that people got sick on the lead in the exhaust that they switched to ethanol an alcohol based on corn. Prohibition was over by decades by then and ethanol was healthier than lead and solved the knocking problem plus farmers made money growing corn to add to the gas.<p>Lead paint was the same way, they hid the fact that it made people sick so they could sell more of it.<p>Lead pipes or copper pipes with lead soldier was used the same way and the safety risks were hidden to people as well.<p>Lead is a neurotoxin and leads to mental illnesses and brain damage. People effected might have violent outbursts and get arrested for crimes. If there is lead in the water supplies of the poor neighborhoods that minorities live in it could be the cause of crime by those who drink the water, bathe in it, cook with it, etc. This is being hidden as well and just now is being reported on by some news media companies.<p>Corporations get away with stuff like that because of the ignorance of the public and their short-term memories. Lead has always been a neurotoxin but people tend to forget that and it gets covered up when it is used in products and pipes and other stuff.