Staying warm and healthy

With the end of ozone season many people feel they can breathe a sigh of relief. However, particle pollution can reach levels of concern at any time of the year. Particle pollution consists of tiny particles that can penetrate deep into lung tissue and can affect the health of both the lungs and the heart.     In Maine we see two peaks for particle pollution levels and weather plays a role in both. One occurs during the summer due to slow moving high pressure systems that get dirtier and dirtier as they move across the continental U.S. The other peak occurs in winter and is largely due to a combination of weather, terrain, and local pollutant emissions.
During long, clear, cold, calm nights, the earth radiates heat outward, allowing the air near the ground to cool faster than the air higher up. This creates what is called an inversion. An inversion acts like a cap trapping pollution closer to the ground. Terrain contributes to higher levels of pollution because valley walls can block light winds allowing pollution to hang around longer.
In wintertime, woodburning for residential heating combines with the other pollution (for example, from vehicles) and can be trapped by an inversion. With the right (or wrong) weather conditions and terrain, particle pollution levels can then climb overnight, especially in valleys and urban areas.
But there are ways we can reduce our contributions to poor air quality in the neighborhood this winter. They include having the furnace cleaned annually and breaking the habit of vehicle idling can help clear the air. If heating with wood, we can reduce harmful emissions by burning seasoned firewood in small, hot fires (which produce less pollution than large smoldering fires). Cleaning the stack or chimney to improve draft and combustion, as well as safety, and not installing devices, such as ‘rainhats’, which slow the movement of the smoke out the stack, are other ways to help clear the air.
Other pollution-reducing measures include replacing an old woodstove or fireplace insert with one that emits less particle pollution. These new devices also produce much more heat per unit of wood than older models, so they pay for themselves in a few years. (Pellet stoves are much cleaner than any other wood burning appliance.)
Whether it’s particle pollution or ozone that’s the concern, Maine’s Department of Environmental Protection forecasts air quality year round, throughout the state. These forecasts and much more information can be found at: www.mainedep,com (click on Air Quality Forecast). A brief forecast discussion is also available (toll free) at 800-223-1196. Both provide the daily Air Quality Index (AQI) that can help with planning activities.
People with respiratory and/or heart disease, the elderly and children should take precautions when air quality is likely to be ‘Moderate’, ‘Unhealthy for Sensitive Groups’ or ‘Unhealthy’. This will reduce the need for medications and doctor or hospital visits.
So stay warm this winter and “Keep an eye on the AQI.”
   This column was submitted by Martha Webster, air quality meteorologist with the Maine Department of Environmental Protection’s (DEP) Bureau of Air Quality. In Our Back Yard is a weekly column of the DEP. E-mail your environmental questions to infoDEP@maine.gov or send them to In Our Back Yard, Maine DEP, 17 State House Station, Augusta, ME 04333.