When your child goes outside for a “breath of fresh air,” sometimes that air may contain higher levels than normal of unseen pollutants or irritants that may affect her asthma and her lung development. Inflamed airways are usually very sensitive to environmental irritants that aggravate asthma.

You can monitor the air quality of the neighborhood you live and where your child attends school via radio or television broadcasts, the Internet, or other services on a daily basis. The air quality can vary by season or by other environmental events (such as smoke from forest fires).

While much of this area on environmental factors and asthma is still under investigation, research is now available to help you and your child breathe better outdoors.

Particle Pollution and Smog

When your child has asthma, you may have noticed that his symptoms may get worse when the air is polluted. Air pollution can make it harder to breathe — causing symptoms such as coughing, wheezing, and chest discomfort.

To protect your child's health from air pollution, you can first observe if his asthma symptoms occur more often when he is physically active outside — specifically when the air is polluted. This may indicate that he is sensitive to air pollution.

Also, if asthma symptoms arise the day after he has been outside in the polluted air, this may indicate that his exposure to this air has increased his sensitivity to other triggers indoors, such as dust mites or mold.

To anticipate when the outside pollution might cause your child problems, keep in mind that:

• Ozone is often worst on hot summer days, particularly in the afternoons and early evenings. Urge your child to limit physical activities to early in the morning or later evening hours on smoggy days.

• Particle pollution can be bad any time of year, even in the fall and winter — especially when the weather is calm and the air pollution builds up.

• Particle levels have been found to be high within a third of a mile near major highways and near busy roads during rush hour.

• Particle levels can be high around factories, and when smoke is in the neighborhood air from wood-burning stoves, fireplaces, or burning vegetation.

• Changing weather conditions, such as changes in temperature and humidity, barometric pressure, or strong winds, can trigger asthma. Cold weather — when the air becomes dry and chilly — could cause respiratory problems.

Newly Identified Environmental Triggers

Recent research also has been uncovering new asthma triggers. One of those triggers is related to “red tide toxins” — blooms of ocean algae that are concentrated along shorelines and produce highly potent aerosolized toxins.

The red tides, which occur worldwide, increase respiratory symptoms in patients with asthma. In studies along the Florida Gulf Coast, the red tide toxins were found to affect asthma patients in just one hour at the beach when exposed to the toxins. Researchers recommend that those with asthma choose another beach when red tides appear because they tend to be localized along the coastal waters.

Sometimes, the origin of various asthma triggers may begin far away. The U.S. Geological Survey has been monitoring the transport of dust through tradewinds from northwest Africa to the western Atlantic Ocean and Caribbean regions, noting that it may be responsible for a number of environmental problems, including the increased occurrence of asthma in humans. The dust comes from the expanding Sahara/Sahel desert region of Africa and carries a wide variety of bacteria and fungi.