Particle pollution in the air comes from local, regional, national and even global sources, primarily fuel combustion, road dust and fires. It can be bad at any time or location, but especially:
- When the weather is calm, allowing pollution to build up.
- Around factories, during rush hour and near busy roads.
- When there is smoke in the air from wood stoves, fireplaces, forest fires or burning vegetation.
Weather conditions in different parts of the state can affect particle pollution levels.
In the Connecticut River Valley region of Western Massachusetts, for example, temperature inversions that limit the mixing of air can result in higher particle pollution levels than otherwise would be expected. Particle pollution also can be transported from out-of-state, affecting air quality in Massachusetts.
The Department of Environmental Protection (MassDEP) has been monitoring ambient air quality for a variety of pollutants, including particles, with a network of monitors across Massachusetts since the 1960s and issues a Daily Air Quality Forecast for fine particles year-round.
The MassDEP monitoring network is designed to characterize ambient air quality over wide areas. Particle pollution levels at the monitoring site nearest where you live can provide a rough indication of pollution levels in your community, but keep in mind that local sources – including diesel trucks, construction that generates dust and nearby home wood burning – affect actual conditions in your immediate neighborhood.
For a quick “snapshot” of air quality in your community and region, look at the map on the right, which uses a color-coded Air Quality Index (AQI) to tell you how clean or polluted the air is.