Environment DEC
From the July 2007 issue
DEC Using More Stringent Measurement for Air Quality Forecasts
New York State will be incorporating a new, more stringent air quality measurement in forecasting air quality health advisories. The revision incorporates a reduction enacted by the United States Environmental Protection Agency (EPA) in fine particulate matter exposure to protect public health and the environment.
In December 2006, the EPA revised the 24-hour national ambient air quality standard for PM 2.5. The standard was made more stringent by reducing PM 2.5 to 35 micrograms per cubic meter in response to the latest research indicating that the previous standard of 65 micrograms per cubic meter did not adequately protect public health. While the EPA has not yet revised the AQI to reflect the lower standard, DEC determined that the new standard should be used when forecasting PM 2.5 levels to better protect public health.
Particulate Matter
Exposure to PM 2.5, which comes from vehicle exhaust and other sources, can worsen medical conditions such as asthma and heart disease, especially in children and the elderly
Fine particulate matter (PM 2.5) consists of tiny solid particles or liquid droplets in the air that are 2.5 microns or smaller in diameter. PM 2.5 can consist of many different types of particles and often comes from processes that involve combustion (e.g., vehicle exhaust, power plants or fires) and from chemical reactions in the atmosphere. Exposure can cause short-term health effects such as irritation to the eyes, nose and throat, coughing, sneezing, runny nose and shortness of breath. In addition, exposure to elevated levels of fine particular matter can worsen medical conditions such as asthma and heart disease. People with heart or breathing problems, children and the elderly may be particularly sensitive to PM 2.5.
AQI and Health Advisories
The Department of Environmental Conservation (DEC) makes daily determinations of anticipated air quality by forecasting the expected ground-level ozone and PM 2.5 levels in the air and uses the Air Quality Index (AQI) developed by the EPA. This index is a tool that helps determine when air quality is or could be compromised by pollution. If the AQI is forecast to exceed certain values related to ambient concentrations of PM 2.5 or ozone, an air quality health advisory is issued by DEC and the Department of Health for the specific region or regions predicted to experience elevated pollution levels for ozone, fine particulate matter or both. The higher the AQI value, the greater the health concern.
Depending on air quality conditions, the revised standard and DEC's adoption of it in our air quality forecasts could result in an increased number of air quality health advisories, even if particle concentrations remain essentially at the same levels seen in previous years.
