• The US EPA measures the general state of air quality by comparing levels of six common air pollutants, also referred to as criteria pollutants, or urban air pollutants. These are:
  • ozone
  • sulfur dioxide
  • particulate matter
  • carbon monoxide
  • nitrogen dioxide
  • lead
• For more information about each or these pollutants see Environmental Defences' Scorecard <http://www.scorecard.org/env-releases/cap/pollutant-desc.tcl>.

• The common pollutants are monitored to produce information on risk when levels are high enough to pose hazards to sensitive groups within populations or the general population itself. The EPA calls this the Air Quality Index (AQI). The AQI represents the total level of pollutant concentrations for ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide. When the AQI is in a range of 0-50 risk from air pollutants is low, 51-100 is moderate, and greater than 100 indicates that air pollution levels may be unhealthy for sensitive groups. If it is above 150, air pollution levels pose potential risk to the general population.
• The graph below shows a general air quality trend for the Cleveland, OH metropolitan area.

• For today's air quality and historical air quality data for Northeast Ohio: Northeast Ohio Air Quality Online <http://neoair.noaca.ohiou.edu/quality/quality.asp>

• For air quality data for anyplace in the country: US EPA's Air Quality Index - AIRNow <http://www.epa.gov/airnow/> and Environmental Defences' Scorecard <http://www.scorecard.org>

Air Toxics

• The EPA has identified almost 200 additional air pollutants called hazardous air pollutants (HAPs). Of these, EPA has identified 33 priority air toxics:
  • benzene
  • mercury
  • PCBs
  • perchloroethylene
  • trichloroethylene
  • vinyl chloride
  • dioxins/furans
  • formaldehyde

• The USEPA National-Scale Air Toxics Assessment provides estimates of air toxics exposures across the country.
• See the Hazardous Air Toxics in Cuyahoga County section of the Air Pollution home page.