According to the US Environmental Protection Agency (EPA), criteria pollutants are the particulate matter such as PM1, PM2.5 and PM10, photo-chemical oxidants and ground level ozone, carbon- monoxide, Sulphuroxides, nitrogenoxides and lead. These pollutants are responsible for causing serious health and environmental hazards such as, smog, acid rain, and property damage etc. These pollutants are termed as criteria pollutants because as per the Clean Air Act, 1963, US EPA sets National Ambient Air Quality Standards based on the human health-based and/or environmentally-based criteria. The sources and effects of criteria pollutants are given below in Table 1.
Much of the Air Quality research has focused on the levels of fine particulate matter known as PM2.5 and PM10. These microscopic particles are 20 times smaller than the width of a human hair and are the most damaging to human health. They can be metals, organic compounds or the by-products of combustion from crop residue and biomass burning, emissions coal-fired power stations, dust from construction and demolition activities, mining and stone crushing, hot-mix plants, pollutants from cement and steel plants, dust storms from arid regions, vehicular emissions, DG sets and industries as shown in (Fig. 1).
WHAT ARE THE SOURCES OF AIR POLLUTION?
INDUSTRY &
ENERGY SUPPLY
DUST
AGRICULTURAL
PRACTICES
TRANSPORT
WASTE
MANAGEMENT
HOUSEHOLD
ENERGY
TABLE 1 : CRITERIA POLLUTANTS AND THEIR EFFECTS (CPCB)
Criteria pollutants |
Emission sources |
Major effects |
||
Natural |
Anthropogenic |
Health |
Environmental |
|
Sulfurdioxide (SO2) |
Volcanicemissions |
Burning of fossil fuels, metal smelting, petroleum refining etc. |
Respiratory problems, heart and lung disorders, visual impairment |
Acid rain |
Nitrogendioxide |
Lightning, forest fires |
Burningof fossil fuels, biomass and high temperature combustion processes |
Pulmonary disorders, increased susceptibility torespiratory infections |
Precursor of ozone formation in troposphere, aerosol formation |
Particulatematter (PM) |
Wind blown dust, pollen spores, photo-chemically produced particles |
Vehicular emissions, industrial combustion processes, commercial and residential combustion, construction |
Respiratory problems, liver fibrosis, lung/livercancer, heart stroke, bone problems |
Visibility reduction |
Carbonmonoxide (CO) |
Animal metabolism, forest fires, volcanicactivity |
Burning of carbonaceus fuels, emission from IC engines |
Anoxemia leadingto various Cardio vascular problems. Infants, pregnant women, and elderly people are at higher risk |
- |
Ozone (O3) |
Present in stratosphere at 10 – 50 km height |
Hydrocarbons and NOX upon reacting with sunlight results in O3 formation |
Respiratory problems, asthma, bronchitisetc. |
O3 in upper troposphere causes green house effects, harmful effects on plants as it interferes in photo synthesis and results in death of plant tissues since it assists in the formation of Peroxyacety lnitate (PAN) |
Lead (Pb) |
- |
Metal processing plants, waste incineration, automobile exhausts, lead-acid batteries, industrial effluents etc. |
Seriouseffects on central nervous system sinceitis absorbedrapidly in blood stream, anemia, toxic for soft tissues and bones. |
- |
