Editor’s Note: Update with city information at 12:15 p.m.
BOSTON – The Massachusetts Department of Environmental Protection has issued an air quality action day Middlesex County, including MetroWest.
An air quality action day means that ozone within the region may approach or exceed unhealthy standards.
The alert is in effect through 11 p.m. July 19.
The DEP identifies a handful of causes for unusual levels of pollutants in the air, among them the direction of the wind and certain weather conditions. Warm weather and increases in direct sunlight can drive up the production of ozone, according to MassDEP.
Every one is advised to take precautions, including avoiding direct sunlight or strenuous activities outdoors.
Boston Mayor Marty Walsh has opened cooling stations. Framingham mayor Yvonne Spicer has not announced anything as of noon today, July 19.
Swimmers may not swim however at Lake Waushakum beach which has not passed a water quality test since June.