COMPARATIVE AEROSOL STUDIES OF PACIFIC RIM CITIES - SANTIAGO, CHILE (1987), MEXICO-CITY, MEXICO (1987-1990) AND LOS-ANGELES, USA (1973 AND 1987)

The UC Davis Ar Quality Group has performed studies on urban air quali ty since 1973. Recently, with the active collaboration of scientists i n Mexico and Chile, these studies have been extended to other Pacific Rim cities of similar climate. From such comparisons, the successes (a nd failures) of control strategies can be inferred and compared to Los Angeles' progress, 1973 through 1987. An early and rather surprising result is the rough equivalence between Los Angeles, Mexico City, and Santiago in terms of several classes of fine (D-p < 2.5 mu m) particle s. However, coarser particles are far more prevalent in Mexico City an d Santiago than Los Angeles. Finally, in many ways, Los Angeles of 197 3 was worse than Mexico City and Santiago today. Thus, the progress of Los Angeles gives hope for similar improvement given suitable policie s.