Feb. 23, 2006 –
Two PM 2.5 monitors in the Roanoke Valley exceeded the EPA annual health standard during 2005. The Salem monitor, located at the Market Street Fire Station, had an annual arithmetic mean of 16.0 micrograms per cubic meter (16.0 ug/m3). The Roanoke monitor, located at the Raleigh Court Library, had an annual arithmetic mean of 15.1 ug/m3.
The U.S. Environmental Protection Agency annual health standard for PM 2.5 is 15.0 ug/m3. Last year was the first time since 2002 that a PM 2.5 monitor in Virginia has exceeded the annual standard. Three of the seventeen Virginia monitors violated the standard in 2005. The Arlington County monitor, located at Aurora Hills Visitors Center, also exceeded the standard with a mean of 15.3 ug/m3.
Particulate matter, or PM, is the term for particles found in the air, including dust, dirt, soot, smoke, and liquid droplets. Particles less than 2.5 micrometers in diameter (PM 2.5) are referred to as “fine” particles and are believed to pose the largest health risks. Because of their small size (less than one-seventh the average width of a human hair), fine particles can lodge deeply into the lungs. PM 2.5 is primarily the result of industrial burning, tailpipe emissions, smoke from wood stoves, and open and prescribed burning.
PM 2.5 is associated with serious health effects including increased hospital admissions and emergency room visits for people with heart and lung disease. Significant health problems from breathing PM 2.5 are aggravated asthma, increases in respiratory symptoms like coughing and difficult or painful breathing, chronic bronchitis, decreased lung function, and premature death.
PM 2.5 is also associated with work and school absences and is the major source of haze that reduces visibility in many parts of the United States, including our National Parks.
During the third quarter of 2005, the Salem monitor showed the highest quarterly mean recorded in Virginia (since Virginia Department of Environmental Quality began listing data in 1999) at 24.3 ug/m3. Also during the third quarter of 2005, the Roanoke monitor had the second highest quarterly mean ever listed in Virginia at 22.7 ug/m3.
There is a third monitor in the Roanoke Valley that collects PM 2.5 data but that monitor is not used to determine the annual standard. Located at Round Hill Montessori in Roanoke, it is used to provide current Air Quality Index readings for the Valley.
Data from DEQ monitors is not official until quality assured by DEQ and EPA.