Acid Deposition of Photochemical Oxidation Products — A Study Using a Lagrangian Trajectory Model

Photochemical air pollution has long been recognized as one of the major causes of such adverse environmental impacts as: visibility degradation, plant deterioration, eye irritation and lung function impairment. In addition, oxidation of both nitrogenous and sulfurous emissions can lead to acidic deposition products, notably nitric acid (HNO₃) and sulfuric acid (H₂SO₄), that can have major long term impacts on ecosystems. Indeed, the consequences of acid deposition from photochemical reactions may be felt for extended periods after the removal of the source and, in some cases, may be irreversible. This situation, coupled with the need for a methodology for relating changes in precursor emissions to ambient air quality, was one of the major motivations for the research reported in this paper.