Air pollution might reduce asthma rescue inhalers’ effectiveness, suggests a study published in Chest and reported by Reuters Health.

Researchers examined 85 children with asthma (ages 7 to 12), who lived in Mexico City, to determine how air pollution might affect their rescue inhalers’ performance.

The findings showed higher levels of certain air pollutants, especially nitrogen dioxide and ozone, made the rescue inhalers less potent.

What researchers noticed is that even though the inhalers remained functional, the children just did not seem to react as favorably to the medication. (Inhaler potency seemed to decrease by about 15 percent when nitrogen dioxide levels in the air increased.)

On the other hand, rescue inhalers did provide more effective immediate relief for children who regularly used them to help control persistent asthma.

These findings are consistent with other studies and may explain why air pollution triggers symptoms in asthmatics, said Fernando Holguin, MD, the study’s team leader at the University of Pittsburgh in Pennsylvania.

The researchers noted that they need further, large-scale investigations to confirm their findings.

Learn how cleaning the air in your home can help reduce asthma symptoms here.