Published online: October 6, 2017
Air pollution encountered outdoors or in the indoor home environment, produced by indoor sources or by outdoor pollutants seeping in, can cause increased respiratory symptoms and lower lung function for children with asthma. Recent studies have identified allergens in school classrooms as a trigger for increased asthma symptoms in children. However, little is known about the impact air pollution has on children in the classrooms where they spend the majority of their day.
In a research article recently published in The Journal of Allergy and Clinical Immunology (JACI), Dr. Gaffin and colleagues investigated whether nitrogen dioxide (NO2) affected lung function and respiratory symptoms in children with asthma attending inner city schools. NO2 is a gaseous component of air pollution generated by burning fossil fuels. At two separate times during the school year, the research team collected samples of NO2 inside inner city classrooms over the course of a week while school was in session. They assessed the relationship of air pollution levels to participants’ lung function testing performed at the schools at the same time. Asthma symptoms were assessed by telephone at other times during the school year.
The levels of NO2 in the school classrooms the researchers visited were well within the US Environmental Protection Agency recommended thresholds for air quality standards. Despite this, there was a direct correlation between increasing levels of the pollutant and greater airway obstruction, a hallmark of asthma. Childhood asthma is known to be related to allergies and allergic airways inflammation in most cases. However, the decrements in lung function found in this study were not specific to children with allergies and exposure to air pollution did not increase airway markers of allergic inflammation.
The authors’ findings suggest that school classroom exposure to air pollution may directly contribute to worsening airways obstruction in children with asthma attending inner city schools. This exposure, among other allergens and irritants present in schools, may be an important cause for airway obstruction in children with asthma. Addressing air quality and allergen exposures in schools may be an effective means to improve the health of many children with asthma.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.