(High levels of PM 2.5 in Calexico)….PM 2.5 is a finite particulate matter resulting mostly from vehicle emissions.
The Air Pollution Control District says at 2:00 am Thursday the Air Quality Index indicated the 24-hour average of PM 2.5 reached a level of 111. This represented a condition of Unhealthy for Sensitive Groups. The Sensitive Groups include those with respiratory or heart disease, children and the elderly. By 6:00 am the levels had reduced at the Ethel Street monitoring station for a condition of Moderate air quality in the border city. When Unhealthy conditions are reached, it is suggested the Sensitive Groups reduce prolonged or heavy exertion.