Towards a Science-Based Integrated Ozone-Fine Particle Control Strategy

摘要: Epidemiology studies relating health effects to ambient levels of ozone and fine particles have led the modification standards in United States for these pollutants (substitution an 8-h standard at 80 ppbv, addition 24-h annual particles). The interrelationships atmosphere suggest need integrated, science-based strategy their control. Secondary formation has been controlled through emission controls on VOC NOx precursors. Fine are secondary products largely resulting from oxidation precursors (SO2, NOx, VOCs). key intermediates both types process free radical species photochemically labile compounds that produce them atmosphere. However, due complex nonlinear nature processes, reductions may lead unexpected changes particle rates. For example, reduction emissions reduce nitric acid levels, but also increased rates sulfate clouds ammonia availability neutralization acidic aerosols. Reductions SO2 aerosol summer, no effect other seasons. VOCs urban core areas, not elsewhere. An regionally seasonally specific, is needed cost-effectively levels.