| Popis: |
Ozone and particulates are two of the most important atmospheric pollutants in terms of human health. Elevated ozone was first associated with smog events in cities with heavy automobile traffic, especially Los Angeles. Elevated ozone and particulates also occur in multiday events over regions 2000 km or more in extent, including both urban and rural areas. These occur in densely populated industrialized regions of the United States, Europe, the Mediterranean, and (more recently) China. Ozone and particulates both have serious effects on human health, cause damage to agricultural crops, and affect climate. Formation of ozone and particulates involves chemical production from organics and nitrogen oxides in the presence of sunlight and warm temperatures. The process is significantly impacted by biogenic emission of organics, primarily from trees. In recent years, pollution controls have been partially successful in reducing ozone and particulate levels in the United States and Europe. This chapter describes the formation process for ozone and particulates, their relation to organics, nitrogen oxides, biogenic emissions, atmospheric dynamics and global cycles, impacts on health, agriculture, and climate. |
