midley concluded that if he added lead to gasoline, he could... prevent knocking in internal combustion engines, so until the 70s, lead was used as an additive to gasoline almost all over the world, but suddenly it was revealed lead was very harmful for our health. it wasn't the first disaster left by midgely. he was a person who discovered chlorofluorocarbons combinations for the first time, and in 1941 the american chemical society gave midley its highest award the priestly medal. later on, it was revealed that cfcs have ozone depleting effects and midgely was named the most harmful scientist in history. in another part, gardner mentions the volkswagen scandal known as diesel gate. in 2008, north american and european countries decided to use solution called add blue to reduce air. add blue is made up of 32 and a/2% pure orea and 62 and a/2% deionized water and is widely used in euro 5 and euro. six automobiles. the solution is added to the catalyst section of diesel run cars and reduces the poisonous gases of nitrogen oxides to a large extent. it is used in many engines and large vol