Good health depends upon a number of different measures, one of which is the air we breathe. We can’t live without it and we can’t live with it if it is so dirty it makes us sick.
Pollution control standards are based on the cleanliness of the air we breathe, the air quality of the atmosphere. In the United States, the Air Quality Index (AQI) has been defined as a standardized measure for the cleanliness of the air.
The Air Quality Index was established by the US Environmental Protection Agency (EPA) and is based on a multi-level assessment of air quality. The cleaner the air, the healthier it is, of course.
The EPA’s Air Quality Index is based on a scale that runs from zero to 500, with the lower number of particulates measured in the air, the cleaner and healthier the air.
Air quality is measured by units of ppm (particulate parts per million). Pollutants measured are ozone and other gases and toxic substances, except pollen, that make the air hazardous to breathe.
When air quality measurements reveal a pollution rate of 0 to 50 ppm, the EPA considers this good. Moderate air quality measures at 51 to 100 ppm and 101 to 150 ppm is considered unhealthy for sensitive groups. The scale climbs through the unhealthy, very unhealthy, and hazardous ranges.
Canada and the United Kingdom also have air quality indices in place. Their standards call for much higher levels of air cleanliness than those currently set by the US EPA.
The general assumption is that Canada’s air quality standards are based on protecting people’s health while US air quality standards protect industry.
In Canada, an air quality measure of more than 101 ppm is considered very poor, their most dangerous rating level, whereas in the US it is merely considered unhealthy to certain people.
An EPA proposal from June 2007 suggests a tightening of air quality standards for the US. Scientific advisors to the EPA call for a substantial reduction in the accepted standards of air quality based on the current system.
The newly proposed air quality rating system would place the designation of unhealthy to the one that is currently considered merely moderate.
Many of the nation’s lawmakers and general population welcome this improved standard in air quality.