2010 Feb.: VA: Virginia Air Quality Monitoring (Particulates)
Virginia Department of Environmental Quality
AIR QUALITY MONITORING
o ensure that all Virginians have healthy and clean
air to breathe, the Department of Environmental
Quality monitors Virginia’s air pollutant levels daily.
DEQ’s Offi ce of Air Quality Monitoring works with the
Environmental Protection Agency to uphold standards
for clean air under the U.S. Clean Air Act and monitors
for the following six main pollutants: ozone, sulfur dioxide,
nitrogen dioxide, carbon monoxide, particle pollution
When present in large concentrations, these pollutants
can cause health problems, including lung irritation
and cardiac stress, can aggravate conditions like asthma
and heart disease and can cause damage to crops
and forests. The EPA established the National Ambient
Air Quality Standards to regulate how much of each
pollutant is allowable in the air. The two agencies work
together to see that Virginia’s air meets these standards.
DEQ issues air quality forecasts for fi ne particulates in
the metropolitan areas of Richmond, Roanoke, Hampton
Roads and Winchester using meteorological, statistical
and collected data. The forecast for Northern Virginia
is issued through a collaborative eff ort with other
state and local meteorologists and monitoring personnel
in the greater Washington, D.C., metropolitan area.
Forecasts and other information are available on DEQ’s
air monitoring web site, http://www.deq.virginia.gov/airmon.
How DEQ monitors air quality
The DEQ Offi ce of Air Quality Monitoring is responsible
for organizing and maintaining the instruments
used in the monitoring network around
the Commonwealth and regularly retrieves data from
approximately 50 monitoring sites in the state. The
agency’s air data analysis group uses the data to make
forecasts of air quality.
irginia’s monitoring stations are primarily in or
near urban areas, such as Richmond, Roanoke,
Hampton Roads, Winchester and Northern Virginia.
Locations are determined by factors such as population
density, emissions sources, permitting needs, modeling
results and site accessibility. The offi ce works with the
Maryland, Washington, D.C., Alexandria and Fairfax
County to monitor air quality in Northern Virginia.
DEQ’s Anton Sorkin installs a particle pollution monitor at a
Henrico County site.
DEQ also operates some stations in rural areas that are
near these urban areas. They provide background air
quality data and help assess the amount of pollution
that urban areas contribute to surrounding air. In addition,
rural sites provide examples of long-range transport
of pollution that comes into Virginia from outside
its borders. For instance, the station in Shenandoah
National Park, which is 3,000 feet above sea level, allows
DEQ to observe pollutant concentrations high in
the atmosphere that could descend to more populated
he monitors used to measure air quality operate
continuously and must be located in secure, temperature-
controlled shelters that are powered with electricity
and connected to telephone service. The fi gures
are compiled and automatically sent to the DEQ and
EPA AIRNow web sites, where they are used to produce
maps and inform the public of the current Air Quality
Index (AQI), a calculated measurement of air quality
from ozone and fi ne particle pollution information over
several hours. A higher AQI indicates a higher level of
air pollution and, consequently, a greater potential for
629 E. Main Street ~ Richmond, Virginia 23219
804-698-4000 ~ (toll-free in Virginia) 800-592-5482
Above: Rockpoint Overlook, Augusta County, Virginia
Air Quality Index
Levels of Health
Good Green 0-50 Good air quality. Little or no health risk.
Moderate Yellow 51-100 Moderate air quality. People who are unusually sensitive
to air pollution may be mildly affected.
Orange 101-150 Unhealthy for sensitive groups. These groups may experience
health problems due to air pollution.
Unhealthy Red 151-200 Unhealthy. The general public may experience mild health
effects. Sensitive groups may have more serious health
Very Unhealthy Purple 201-300 Very unhealthy. Everyone is susceptible to more serious
The Air Quality Index is a measurement calculated daily from ozone and fi ne particle pollution measurements. It is color-coded by level
of health concern.
How monitoring information affects
Virginia focuses primarily on monitoring ground level
ozone and particle pollution.
round-level ozone is a colorless gas formed by the
chemical reaction of pollutants from automobiles,
industries, and other sources, in the presence of sunlight.
Ozone is a seasonal pollutant and occurs mainly
in the summer months during weather periods of hot,
stagnant air. Ozone levels are signifi cantly lower in the
cooler months and, as a result, DEQ’s ozone monitors
run only from April 1 to October 31. Harmful ozone pollution
can lead to aggravated asthma or to infl ammation
and damage to the lungs.
article pollution consists of microscopic particles
of solids and liquid droplets suspended in air, some
of which are so small that they are only one-fi fth the
size of a human hair. This matter is made up of particles
found in soot, dust, smoke and fumes produced from
burning coal, oil, diesel and other fuels. These particles
are of greatest concern because they can be inhaled
deep into the lungs and cause respiratory issues or aggravate
existing lung and heart problems. Particle pollutants
have been linked to chronic bronchitis, asthma
and heart attacks.
DEQ maintains a daily log of current air quality conditions
at http://www.deq.virginia.gov/air and provides the information
to the EPA, news media and other state agencies.
The EPA’s AIRNow web site is another resource for
information on the daily AQI and is located at www.
Future air monitoring issues
EPA made the national air quality standards for ozone
stricter in 2008 and is proposing to make the standard
even more strict in 2010 Many areas of Virginia may not
meet the new standard for ozone depending on where
EPA ultimately sets it. DEQ is working with EPA to devise
strategies to meet the new standard in all areas of
orthern Virginia has been designated nonattainment
for particles because it is part of the greater
Washington metropolitan area. Air quality has improved
in the Washington metropolitan area so that
the area is now meeting the 1997 standards. Information
from all other areas of the state shows Virginia
meets the standards for particles. Once new emissions
controls on PM2.5 precursors take eff ect, DEQ expects
that Virginia will have even better air quality in regard
to particulate matter.
As part of the future monitoring strategy, EPA is placing
added focus on air toxics monitoring. In addition,
EPA is reviewing the existing standards for sulfur dioxide,
carbon monoxide and oxides of nitrogen and is
placing greater emphasis on trace levels of these pollultants.
As a result, DEQ will be expanding its monitoring
network across the state.
nce Virginians are aware of the air quality in their
area, they can take precautionary steps to reduce
future problems and to stay safe and healthy. By reducing
emissions, the public can help reduce pollutants in
the air we breathe.
More information on DEQ’s eff orts is available on the
Offi ce of Air Quality Monitoring web site at http://www.deq.