Urban Air Pollution GISAT 112

Learning Objectives Regions of the atmosphere Amount, composition of air we breathe Names of selected air pollutants Health and environmental effects of air pollutants Air quality status, trends: US, international Tropospheric ozone: formation, precursor sources Supporting concepts –Air quality concentration units –Chemical names, reactions, equations –Combustion reactions –Scientific notation, significant figures –Ideal Gas Law, molar volume

Outline Overview of the urban air pollution issue –Key pollutants, health effects, sources Important scientific and technical concepts –Gases and particles –Inorganic and organic chemicals –Exposure, toxicity, and health risk –Combustion reactions –Balancing chemical equations, stoichiometry –Atmosphere and weather terms Supporting concepts –Concentration units –Significant figures –Ideal Gas Law, molar volume

Overview of Urban Air Pollution Key pollutants Health and environmental effects Sources

Layers of the Atmosphere

Composition Of Air Dry Air78% N 2 21% O 2 0% H 2 O 1% Ar, etc. Typical Air~75% N 2 ~20% O 2 1-4% H 2 O 1% Ar, etc. “etc.” includes the pollutants Pollutants include particles (solid-, liquid-phase)

“Criteria” Air Pollutants CO(Health) NO x (Health, Acid Rain, Smog, Strat O 3 ) O 3 (Health, Smog) SO x (Health, Acid Rain) PM(Health, Visibility) [PM 10, PM 2.5 ] Pb(Health) National Ambient Air Quality Standards (NAAQS) have been developed for these pollutants (see Table 1.4) For info on sources, health and environmental effects, air quality standards and air quality trends: –

PM 2.5 Sampler in Roanoke

Table 1.4 Smaller!

Some Other Air Pollutants Carbon Dioxide (CO 2 ) [re: global warming] Chlorofluorocarbons (CFC’s) Volatile Organic Compounds (VOC’s) Heavy metals (e.g., Mercury) Dioxins Formaldehyde Pesticides Microbials Radon EPA has listed 188 Hazardous Air Pollutants, 31 of which are “urban air toxics”

Source: Masters Toxicity Sites

Health Risk Health risk is a product of two factors: TOXICITY x EXPOSURE Where toxicity is a measure of adverse health effect per unit mass of pollutant And exposure is a measure of the mass of pollutant breathed over a period of time

Effects of Carbon Monoxide

Ozone Trends (from EPA’s 2003 Ozone Report,

Sources and Types of Air Pollutants