Air Pollution

Some Terms..  ppm-parts per million  ppmv-parts per million by volume  ppb-parts per billion  UTC-universal time coordinated(used to be Greenwich Mean Time, also Zulu time)  [ ]-concentration in moles/L

What is air pollution?  Addition of harmful substances to the atmosphere resulting in damage to the environment, human health and quality of life  Can occur indoor or outdoor, in cities and across continents and even globally  Air pollutants consist of: gaseous pollutants, odors, suspended particle matter (dust, fumes, mist and smoke) Sources:

Processes that Polute  Attrition-the wearing or grinding of a substance by friction. This creates small particles called Particulates or fine droplets called Aerosols.  Vaporization-the process in which a liquid changes to a gas.  Combustion-burning

Some Types of Air Pollution  Oxides of Nitrogen (NO + NO 2 = NO X ) Sources: Power plants, cars, forest fires, trains, planes, volcanoes, industry, burning  Sulfur Dioxide (SO 2 ) Sources: Burning of sulfur containing fuels, sulfuric acid production facilities  Carbon Monoxide (CO) Sources: cars, power plants, burning, industry

Some Types of Air Pollution  Particulate Matter (PM 2.5 and PM 10 ) Sources: Dust, power plants, diesel trucks, industry  Lead (Pb) Sources: smelting, lead fuels  Ozone (O 3 ) NO x + Sunlight = Ozone

How does air pollution affect people?  Contributes to: Asthma Emphysema Mortality Cancer  Populations most at risk: Elderly Very young children Outdoor exercisers People with existing respiratory problems

The Clean Air Act  In 1970, the US Congress passed the Clean Air Act in which the Environmental Protection Agency (EPA) established National Ambient Air Quality Standards that set the maximum amount of specific Criteria Pollutants allowed in the outside air.  Criteria Pollutants-to be considered a criteria pollutant-must have health effects.

The Clean Air Act  Caused the formation of the EPA (environmental protection agency) to oversee  Established standards for criteria pollutants:  CO (Carbon monoxide), SO 2 (sulfur dioxide), NO 2 (nitrogen dioxide), O 3 (ozone),Pb (lead), PM 10 and PM 2.5 (particulate matter 10 microns or 2.5 microns)

Clean Air Act  Sources are regulated if they have the potential to emit > 100 tons of any regulated pollutant  Ozone is not directly emitted. (it is a secondary pollutant-means it forms in the atmosphere from other molecules

Clean Air Act  Clean Air Act also established the NESHAPS (national emission standards for hazardous air pollutants)  Carcinogens, mutagens, reproductive toxins  Current list has 188 pollutants

Air Quality Index  Easy to understand  If AQI=100, then concentration of pollutants is equal to national air quality standards  If AQI=over 100, then concentration exceeds the standards  Exceedance-over the standard

Air Quality Index

The End.