Abstract
Two tetraalkyllead (TAL) compounds, tetramethyllead (TML) and Tel, are added to gasoline as antiknock agents. A small amount of this organic lead is emitted unchanged into the atmosphere through automobile exhausts and evaporation from spillage at gasoline stations. The kinetics and mechanism of the principle homogeneous and heterogeneous reactions of TML and Tel have been investigated to determine the breakdown of these leads in the atmosphere. Heterogeneous reaction pathways have been investigated by exposing atmospheric particulates to tal vapors. Results indicate that the overall rates of breakdown on a photochemically active sunny summer day are estimated to be as fast as 93%/hr from Tel and 29%/hr for TML. Both compounds are expected to be relatively stable at nighttime.