Thomas Midgley, Jr. held over one hundred patents for his mechanical engineering and chemistry advancements. Certainly not winning any prizes from environmentalists, it was Midgley who developed the lead-based additive for gasoline, as well as some of the first chlorofluorocarbons.
His work with chlorofluorocarbons resulted in the first non-combustible and non-flammable refrigerant: freon.
His work in developing lead additives to gasoline successfully addressed the problem of engine knock in internal combustion engines. It almost put an end to his career, however, and he had to take a prolonged vacation to recuperate from lead poisoning.
As it turned out, his inventions would be the death of him, but it was not an environmentally-dangerous device that did him in. In 1940, at the age of 51, Midgley was disabled when he contracted polio. Ever the inventor, he developed an elaborate system of ropes, pulleys, and levers to help lift him in and out of bed. It all worked fine until one day when he got tangled up in the ropes and died of accidental strangulation.