To be fair to the guy, the deleterious effects of his technologies weren't known at the time.It is safe to say that the American inventor Thomas Midgley Jr. Is responsible for more deaths and illness and has caused more damage to the world environment than any other person who has lived.
First came up with the idea that lead in petrol would reduce engine knock. The legasy is that millions of additional people die each year from respiratory problems.
Next, not content with that he went on to discover that chlorofluorocarbons (cfcs) made exceedingly efficient refrigerants.
He has succeeded in poisoning of three generations of children with future generations to be effected, increased the risk of skin cancer and other skin problems related to UV rays, and has contributed greatly to global warming.
Finally, he contracted polio. He invented a device to help him get out of bed in the morning. In an accident he was strangled in his own device.
My thought on this is that is could not happen to a more deserving person.
(Lead toxicity was just gaining attention at that time.)