The air is brisk. Winter is almost here. We bundle up and head outside perhaps seldom considering that the “fresh air” surrounding us may be filled with fine particles: dust, soot, sulfates, nitrates and various microscopic bits.

Each day, we inhale an average 40 pounds of air — compared to the six pounds we eat and drink — with little personal choice in the matter. Fine particles can become lodged in delicate lung tissue, decreasing lung function and pass unimpeded into the bloodstream — a hazardous situation for everyone, but especially people with respiratory and cardiovascular diseases.

Children are particularly vulnerable to the effects of poor air quality due to their high metabolisms and developing organs.

Because of Helena’s topography of , we are more susceptible to air inversions that trap fine particulate matter. During the winter months, a majority of what is in our air is residential wood smoke. Over the last few years, the Montana Department of Environmental Quality contracted with the University of Montana’s Center for Environmental Health Studies (CEHS) for air pollution studies to identify the sources of fine particulate matter in several Montana cities, including Helena.

Last winter, 66 percent of fine particulate matter less than or equal to 2.5 microns in diameter in the air was attributable to wood smoke, according to CEHS.

In 1997, the U.S. Environmental Protection Agency determined that fine particulate matter is more dangerous than larger-sized particulate matter. A new 2.5-micron standard was established in addition to the old 10-micron standard.

By 2006, health studies confirmed fine particulate matter was a public health hazard and the 2.5-micron standard was lowered. The new EPA standard is now in place, and the City-County Health Department is working with DEQ to coordinate air quality reporting as we transition from our old, outdated ordinance to the new, more protective standards. In the meantime, we will report air quality using new standards.

The official regulatory air quality season in Lewis and Clark County runs from Nov. 1 through March 1. During this time of year, air quality is monitored and conditions are reported daily using a 24-hour air quality hotline. We also provide daily media updates. When watch or alert conditions exist, we notify schools, childcare facilities and others. During an air quality alert, the public is required to discontinue burning wood.

As more people look to wood burning to reduce home heating costs, we may expect to see more wood smoke pollution in the valley. The new categories of air quality may result in increased requests to residents to stop or limit wood-burning activities during periods of high concentrations of 2.5 micron particles.

Your cooperation in reducing and discontinuing wood burning will help us avoid exceeding the new EPA standards. If we violate these standards, EPA will designate the Helena area as failing to meet these standards, radically changing our air quality program and will ultimately resulting in increased regulation and enforcement activities.

To avoid the potential for increased regulation and enforcement, and to help residents understand their roles in lowering air pollution levels, the City-County Health Department and Montana DEQ recommend the following guidelines to reduce particulates.

• Limit the use of wood burning stoves, but if you must burn use dry, well-seasoned, medium-sized wood. Wet wood does produces more smoke.

• Consider replacing older, less efficient wood stoves with EPA-certified wood stoves or pellet stoves.

• Never burn painted or treated wood, trash or colored paper, which give off harmful chemicals and more smoke as they burn.

• Start a fire with small, dry kindling to establish a hot flame.

• Do not put too many logs in the stove.

• Keep air intake and dampers open enough to maintain a clean, hot fire.

• Clean your chimney regularly.

Local air quality affects how we live and breathe. Like the weather, it can change from day-to-day or even hour-to-hour. Call the health department’s 24-hour hotline at 447-1644 for current air quality conditions or visit DEQ’s “Today’s Air” Web site, todaysair.mt.gov/.

Melanie Reynolds is the Health Officer at the Lewis and Clark City-County Health Department.