County extends air pollution warning for Mon Valley

Allegheny County is warning that along with the warm weather there is a continued air quality problem at least through Monday morning.

On Sunday afternoon, the Health Department said particulate matter in the air will continue to be elevated and the air quality program will reassess conditions Monday after the weather inversion is expected to break.

Young children, the elderly, and those with respiratory problems, such as asthma, emphysema, and bronchitis, are especially vulnerable to the effects of air pollution and should limit outdoor activities during this time, the county said.

More information about fine particulate matter (PM2.5), as well as the current monitored data can be found at: https://www.alleghenycounty.us/ Health -Department/Programs/AirQuality/Air-Quality.aspx

The Health Department initially issued an air pollution warning Saturday morning for the Mon Valley for the remainder of Saturday and all of Sunday.

The Health Department said the 24-hour standard for the pollutant PM2.5 had been exceeded at one of its monitoring stations in the Mon Valley and was likely to continue.

PM2.5 is the term for fine inhalable particles that are a mixture of solids and liquid droplets found in the air, with diameters that are generally 2.5 micrometers and smaller.

To get a sense of how small 2.5 micrometers is, the Environmental Protection Agency compares it to the scale of a human hair. It says the average human hair is about 70 micrometers in diameter — making it 30 times larger than the largest fine particle.