Ozone PM2.5 Carbon Monoxide Nitrogen Dioxide Sulfur Dioxide Lead
The six pollutants listed below are considered "criteria" pollutants
and have National Ambient Air Quality
Standards (NAAQS) set by the EPA Office of Air Quality Planning and
||A colorless gas that is a major constituent of photochemical
||Forms in the air from other pollutants -- volatile organic
compounds (VOCs) and nitrogen oxides (NOx). Ozone does not come directly
from tailpipes or smokestacks. The VOCs that form ozone come from
vehicle and industrial exhaust as well as evaporation of gasoline,
solvents and paints, and many other sources.
||Irritates the lungs and breathing passages, causing
coughing and pain in the chest and throat. Increases susceptibility
to respiratory infections and reduces the ability to exercise. Effects
are more severe in people with asthma and other respiratory ailments.
Long-term exposure may lead to scarring of lung tissue and lowered
lung efficiency. When ozone reaches unhealthy levels, children and
people with asthma are most at risk.
||Solid matter or liquid droplets with aerodynamic diameter
of 2.5 microns and less.
||Diesel cars, trucks and buses, power plants, industry
and many other sources.
|| Aggravates existing heart and lung diseases, changes
the body's defenses against inhaled materials, and damages lung tissue.
The elderly, children and those with chronic lung or heart disease
are most sensitive. Lung impairment can persist for 2-3 weeks after
exposure to high levels of particulate matter. Chemicals in and on
particulates can also be toxic. Very fine particulates can be inhaled
deeply into the lungs. When PM2.5 reaches unhealthy levels,
people with respiratory or heart disease, the elderly and children
are most at risk. Also damages paint, soils clothing and furniture
and reduces visibility.
||An odorless, colorless gas resulting from incomplete
combustion of fossil fuel combustion.
||Automobiles, buses, trucks, small engines, boilers and
some industrial processes. High concentrations can be found in confined
spaces like parking garages, poorly ventilated tunnels, or traffic
intersections, especially during peak hours.
|| Weakens the heart's contractions and lowers the amount
of oxygen carried by the blood. It reduces your ability to exercise
and is dangerous for people with chronic heart disease. It can cause
nausea, dizziness, headaches, and when it's very concentrated, even
death. When carbon monoxide reaches unhealthy levels, people with
heart disease are most at risk.
||A yellowish brown, highly reactive gas that is the primary
ingredient in production of ground level ozone.
||Power plants, large industrial facilities, and motor
|| Irritates the nose and throat, especially in people
with asthma. Appears to increase susceptibility to respiratory infections.
Also combines with volatile organic compounds (VOCs) to form ozone.
When nitrogen dioxide reaches unhealthy levels, children and people
with respiratory disease are most at risk.
||A colorless gas, odorless at low concentrations but
pungent at very high concentrations.
||Power plants, large industrial facilities, diesel vehicles,
and even oil-burning home heaters.
|| Aggravates existing lung diseases, especially bronchitis.
Constricts the breathing passages, especially in asthmatic people
and people doing moderate to heavy exercise. Causes wheezing, shortness
of breath, and coughing. High levels of particulates appear to worsen
the effect of sulfur dioxide, and long-term exposures to both pollutants
leads to higher rates of respiratory illness. When sulfur dioxide
reaches unhealthy levels, people with asthma are most at risk.
||A heavy metal which can cause adverse health effects
either through ingestion or direct inhalation.
||Mostly from a few industrial facilities, such as coal
combustion, smelters, car battery plants, and combustion of garbage
containing lead products. Also from transportation sources using lead
in their fuel, and sanding or wearing away of old lead-based paint.
|| Causes damage to the brain and other parts of the body's
nervous system. Children are most susceptible to the effects of lead.
Lead can also harm wildlife.