Particulate Matter PM 2.5

“Fine particles," such as those found in smoke and haze, are 2.5 micrometers in diameter and smaller. These particles can be directly emitted from sources such as fireplace, smoke, forest fires or they can form when gases emitted from power plants, industries and automobiles react in the air.

There are outdoor and indoor sources of fine particles. Outside, fine particles primarily come from car, truck, bus and off-road vehicle (e.g., construction equipment, snowmobile, locomotive) exhausts, and other operations that involve the burning of fuel or vegetation. Fine particles also form from the reaction of gases or droplets in the atmosphere. These chemical reactions can occur miles from the original source of the emissions and may even be carried by the wind for long distances, even from out-of-state sources. Events such as wildfires or volcanic eruptions can raise fine particle concentrations hundreds of miles from the event.

PM 2.5 is also produced by common indoor activities. Some indoor sources of fine particles are tobacco smoke, cooking (e.g., frying, sautéing, and broiling), burning candles or oil lamps. Adverse health effects of indoor fine particulate pollution are well documented especially from second hand tobacco smoke. Surgeon General - The Debate Is Over

How can PM 2.5 affect my health?
Particles in the PM 2.5 size range are able to travel deeply into the respiratory tract, reaching the lungs. Exposure to fine particles can cause short-term health effects such as eye, nose, throat and lung irritation, coughing, sneezing, runny nose and shortness of breath. Although the nose filters some of the PM 10 particles out of the air, the fine PM 2.5 particles are unaffected by these filters and may lodge deeply in the lungs and even enter the blood stream. Therefore fine particles affect lung function and worsen medical conditions such as asthma and heart disease. Scientific studies have linked increases in daily PM 2.5 exposure with increased respiratory and cardiovascular hospital admissions, emergency department visits and deaths. Recent studies suggest that long term exposure to particulate matter may be associated with increased rates of chronic bronchitis and reduced lung function. People with breathing and heart problems, children and the elderly may be particularly sensitive to PM 2.5.

What can I do to protect my health?
When outdoor levels of PM 2.5 are elevated, going indoors may reduce your exposure, although some outdoor particles will come indoors. If there are significant indoor sources of PM2.5 levels inside may not be lower than outside. Some ways to reduce exposure are to limit indoor and outdoor activities that produce fine particles (for example, burning candles indoors or open burning outdoors) and avoid strenuous activity in areas where fine particle levels are high.

Air filtration systems may be effective in reducing indoor PM 2.5 levels. It is also important to do a home and school evaluation to determine sources of potential asthma triggers and particulate pollution. Some excellent resources are available to assist in this evaluation.

Asthma Friendly Classroom  - Keys to a healthy environment for Children

When levels of PM 2.5 reach the high moderate (yellow range) and especially when an orange or red flag is flying children should be keep in during the parts of the day when the concentrations are the highest. The best time to be outside is during the mid day 10:00am to 2:00 pm. When both PM 10 and PM 2.5 are high special precautions should be taken as the combination can increase the health impacts of particulate matter.