Because of marked improvements in the Air Quality Index of particulate pollutants, parents or children who have asthma or lung disease may want to consider trick-or-treating outdoors in San Diego County.

This at-risk group is most likely to develop symptoms, so adult judgment and informed common sense should be used to make decisions about any outdoor activity. This is true for all adults and children, especially so for those who are at risk.

Many of us have absorbed a big dose of pollutants over the last four days. It takes the body some time to flush out the particulates and toxins. Lungs are still sensitive and vulnerable to irritation and infection during this time, especially among those with existing heart and lung conditions, children and the elderly.

Families who choose to go outdoor trick-or-treating should do so only where the Air Quality Index is at or under 75 ("Moderate" or "Good" air quality), and should not rush about or otherwise increase their exposure to the outdoor air.

All parents should check the Air Quality Index on Friday for the area in which they plan to trick-or-treat. To check the Air Quality Index, go to http://www.sdapcd.co.san-diego.ca.us/air/otoday.html or to www.lungsandiego.org and follow the links. Parents can also call the Air Pollution Control District for the Air Quality Forecast at 858-650-4777.

Note that since monitors don't exist for all areas of San Diego some "hot spots" with elevated levels may exist.

Regardless of the reported levels, if you or your child experience symptoms such as irritated eyes, cough, or sneezing when outdoors, it's best to limit outdoor time.

The use of masks is generally not recommended for extended lengths of time. Simple dust or surgical masks filter large particles but are ineffective at filtering the more harmful smaller particles. Masks that are more effective at filtration also tend to be challenging to breathe through.