Monitoring Regulations for Lead in the Air

Lead (Pb) is a toxic heavy metal which occurs naturally and is also released into the environment by human industry. Prior to regulation in 1980, gasoline had a much higher lead content than it does today. Lead causes neurological and cardiovascular diseases, especially in children.

National Ambient Air Quality Standards

• The National Ambient Air Quality Standards (NAAQS) are set by the Environmental Protection Agency (EPA) under the Clean Air Act. They include six different "criteria pollutants" (ozone, particulate matter, carbon monoxide, sulfur dioxide, nitrogen oxides, and lead) and apply to outdoor air throughout the country.

Lead Standard

• Prior to October 2008, the maximum amount of lead allowed by the Clean Air Act was 1.5 mcg per cubic meter. In 2008, this standard was made stricter, so that any region which has a rolling three-month average lead concentration above 0.15 mcg per cubic meter is designated as a "non-attainment area" and is subject to heavy fines by the EPA.

Monitoring

• The actual job of monitoring the levels of criteria air pollutants falls to individual counties, which ultimately report to the EPA in the form of daily reports and regular inspections. Most major cities have several different monitoring stations. Each pollutant is measured by a specially designed detector. Most use some form of spectroscopy to test pollutant concentrations, and usually take readings every minute or every hour. These results are tallied and sent to the EPA.