The flow of automobile-emitted lead through the Los Angeles basin has been estimated from measurements of particle size distributions, atmospheric concentrations, and surface deposition of lead at various sites around the basin. Approximately 24 metric tons/day of lead as gasoline antiknock additives are consumed. Of this, about 18 tons/day are exhausted to the atmosphere, and 6 tons/day are retained in the cars. Of the exhausted lead, two thirds deposits over the land area of the basin, and one third is advected out of the basin. The lead blown out of the Los Angeles area is the major source of atmospheric lead for regions immediately downwind. Automobile-emitted lead also accounts for more than half of the anthropogenic lead input to the Los Angeles coastal waters. Most of the lead is accounted for by independent estimates of the separate transport processes, but uncertainties in certain pathways are discussed.
ASJC Scopus subject areas
- Environmental Chemistry