How do you know if the air is clean?
The Clean Air Act was enacted by Congress in 1970 to ensure clean and healthy air for all Americans. Through the Clean Air Act, the Environmental Protection Agency (EPA) established federal standards for six criteria air pollutants that are considered
harmful to human health and the environment. Known as the National Ambient Air Quality Standards or “NAAQS” (pronounced “nacks”), the standards establish limits for each of the criteria pollutants.
Air monitoring is the key to understanding how clean the air is in Kentucky. States are required to demonstrate that pollutant levels in the ambient (outdoor) air stay below the NAAQS. In order to do this, each state must operate a network of monitoring stations.
The Kentucky Division for Air Quality (DAQ) has operated air quality monitors since 1967. The current network in Kentucky contains 39 stations, encompassing 148 individual instruments that monitor for criteria pollutants, air toxics, and track meteorological conditions. Of those, DAQ operates 32 sites and 109 instruments; additional air monitors are operated by the Louisville Metropolitan Air Pollution Control district and Mammoth Cave National Park.
“The very first air monitors were basically vacuum cleaners with filters,” says DAQ director John Lyons. “Today’s air monitors are much more sophisticated, but they work on the same principle – sampling the air using some sort of vacuum, and analyzing what’s in the air.”
Depending on the pollutant, air may be collected in a canister, drawn through a filter, or continuously sampled and analyzed. Continuous air monitors operate 24/7, continuously analyzing the air for specific pollutants. Manual samplers require air samples and filters to be collected and analyzed in a laboratory.
EPA determines the type of samplers or continuous monitors that can be used for a particular pollutant and the specific siting criteria for each instrument type. In general, monitors are placed in densely populated areas or near sources of pollution, whether it’s a busy highway or a stationary source with a smokestack.
DAQ staff annually update the Ambient Air Monitoring Network Plan, which contains information about each monitoring station in the network. In addition to maintaining the network plan, DAQ staff are responsible for ensuring that all monitors are safe, secure, and properly operating, as well as processing and assuring the quality of the large amount of data collected for each site and pollutant.
For more information on Kentucky’s air monitoring network, please visit the DAQ’s 2013 Annual Ambient Air Monitoring Network Plan. For general information about ambient air monitoring, visit DAQ’s Air Monitoring Webpage.