Air Pollutants and Their Sources

Six Common Air Pollutants EPA is required to set National Ambient Air Quality Standards for: Lead Sulfur Dioxide Nitrogen Oxides Particulates Carbon Monoxide Ozone The first five are Primary Pollutants – the direct product of combustion and evaporation

Names, symbols, sources, characteristics, and general effects of major air pollutants. 1st 7 are primary pollutants – the direct products of combustion or evaporation. Secondary are from additional reactions

Sources of Primary Pollutants

Sources of Primary Pollutants

Sources of Primary Pollutants

Some Good News…

Secondary Pollutants Primary Pollutants undergo further reaction to form: Ozone Peroxyacetal nitrates (PANs) Sulfuric acid Nitric acid

Effects on Human Health Chronic effects Chronic bronchitis, fibrosis of the lung, heart disease, immune system damage, asthma, cancer, mental retardation Acute effects Death can occur, but usually in weakened individual. Death from air pollution disasters, changes in cardiac rhythm leading to MI. Carcinogens Heavy metals and organic constituents may be responsible for a large number of cancer cases. Include diesel exhaust, soot, benzene

Effects on the Environment Crop damage Forest damage Aesthetic damage Visibility Aquatic ecosystem damage

Controlling Air Pollution Clean Air Act, 1970, 1977, 1990 – setting standards and establishing control methods and timetables to reach standards NAAQS – National Ambient Air Quality Standards – involved in setting standards of the highest level that can be tolerated by humans without effect with a margin of safety. Long and short term standards NESHAP – National Emission Standards for Hazardous Air Pollutants – track and regulate toxic substances Read 21.4