Fine particles in air pollution shown to increase nasal inflammation in asthmatic children.
In a new study published in the Journal of Allergy and Clinical Immunology, French researchers have found that higher levels of exposure to fine particles (PM2.5) caused a significant increase in nasal inflammation. Fine particles PM2.5 are under 2.5 microns in diameter and are often found both outdoors and indoors in areas with elevated air pollution. The study adds to a growing body of evidence that suggests that indoor and outdoor air pollution has adverse effects on respiratory health.
In this small but well controlled study included 85 Paris schoolchildren, 41 with allergic asthma. Over 48 hours, the children’s personal exposure to particulate matter less than PM2.5 was measured using active sampling equipment (small particle counters were attached to their backpacks). Nasal lavage samples were obtained to measure inflammation.
The asthmatic and the non-asthmatic children were exposed to similar levels of PM2.5. However, significant increases in inflammation were noted only in the asthmatic group. The amount of inflammation was also positively correlated to the amount of exposure to PM2.5. The researchers then adjusted for exposure to house dust mite, pollen, cat and secondhand smoke. The associations between exposure to PM2.5 and inflammation in the asthmatic children remained significant.
These results are important in that they give us a pretty good indication that fine particles play a role in the inflammation of allergic asthmatic children. It is not just the allergens. Although larger studies need to be done to confirm these findings, there appears to be good reason to reduce PM2.5 exposure for asthmatics by reducing pollution and improving indoor air cleaning.