Acidic Deposition: State of Science and Technology. Report 23. Indirect Health Effects Associated with Acidic Deposition

摘要

The purpose of the report is to evaluate the potential indirect health effects caused by the mobilization of metals and other pollutants as the result of emissions of acid precursors, their atmospheric transformation to acidic species, and the ultimate deposition of these acidic precipitation products. Acidic deposition is all deposition (both wet and dry) of acidic species to surfaces, including foliage, soils, water surfaces, and exposed materials. The acidic species are primarily sulfur and nitrogen based acids, and the precursors of these acidic species are largely nitrogen oxides and sulfur oxides emissions. For the purposes of the paper, metals emitted concurrently with the precursors of acidic species are considered components of atmospheric deposition. Thus, there are two routes by which environmental levels of pollutants of concern here can be increased: (1) by energy-related combustion processes that emit acid precursors and metals, and (2) by localized acidification of soils or waters, resulting in the mobilization of metals from soils, sediments and other environmental components following acid deposition.