Air pollutants that cause typical smog damage—the silvering, bronzing, and spotting on many agricultural crops— are certain olefinic peroxides, formed when ozone reacts with the vapors of unsaturated hydrocarbons derived from gasoline and other petroleum products. In Los Angeles County alone, annual crop losses have exceeded $500,000 since 1949 when they were estimated to be $479,495.

The above progress report is based on Research Project No. 1085.