chlorofluorocarbons combinations for the first time, and in 1941, the american chemical society gave micheley 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 dieselgate. in 2008, north american and european countries decided to use solution called add blue to reduce air pollution. add blue is made up of 32 and a/2% pure aurea and 62 and a/2% deionized water. is widely used in euro 5 and euro 6 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 volumes including in audi's mercedes. and bmw products, but in 2008, volkswagen announced that the company's 2,000 cc engines do not need add blue. after a while, americans found out they had been badly deceived. volkswagen had used some software with complicated algorithm to bypass the emission standard tests to show lower amounts of pollut