By Mary Stortstrom
MARTINSBURG, W.Va. — A code orange air quality alert was issued by the National Weather Service for Berkeley and Jefferson counties Tuesday, which may mean certain individuals may need to reduce their outdoor activity as the conditions are expected to continue through the end of the week.
According to Fred Durham, deputy director of the West Virginia Division of Air Quality, the alerts focus on two common types of air pollutants – ground-level ozone and fine particulate matter, or PM2.5.
In West Virginia, ozone pollution occurs seasonally and rarely becomes a problem during the winter months. PM2.5 pollution may occur year-round, and is the basis for this week’s alerts.
PM (particulate matter) is the term used for particles found in the air, including dust, dirt, soot, smoke and liquid droplets. These particles can be suspended in the air for long periods of time. PM2.5 particles, named for their size of less than 2.5 micrometers, may pose greater health risks since their small size allows them to lodge deeply into the lungs.
Sources of PM2.5 particles include combustion from motor vehicle engines, power plants, wood burning and other industrial processes.
According to Durham, weather conditions and other meteorological factors can adversely affect PM 2.5 concentrations.
“In this episode, a widespread high pressure center is contributing to stagnant air from southwest Pennsylvania, southeastward down toward Hagerstown, Md. and into the Winchester, Va., area,” Durham said. “This has led to a temperature inversion over much of the affected area, which traps polluted air and prevents it from dispersing as it normally would.”
Durham said pollutant emissions are likely at their usual level, but are concentrated in the region because air is trapped by the high pressure center…