The Effect of PM10 on the Symptoms of Allergic Rhinitis during Spring

Abstract

Objectives: Clarify the effect of PM10 (particulate matter less than 10 μm), which is the major component of air pollution, on the symptoms of allergic rhinitis patients during spring. Methods: We investigated changes in allergic symptoms (rhinorrhea, sneezing, nasal obstruction and sleep disturbance) and nasal obstruction level as measured using a portable peak nasal inspiratory flowmeter (PNIF) in 108 allergic patients. Forty-seven control subjects were also included. Spring pollen counts and PM10 concentrations in Incheon city were also evaluated. We conducted long-term observation of the effect of PM10 on allergic symptoms for 120 days from February to May and compared the changes in symptom scores before and after the 2 days when PM10 concentration was 100μg/m3 (short term). Results: The highest concentration of PM10 during the study period was <150 mg/m3. No significant correlations between PM10 and nasal obstruction ( P = 0.0670), rhinorrhea ( P = 0.1485), sneezing ( P = 0.3991), itching ( P = 0.2044), sleep disturbance ( P = 0.4413) and the sum of all symptoms ( P = 0.0816) were identified. However, the variation in nasal obstruction, as assessed by PNIF, was significantly correlated with the PM10 level ( P = 0.0410). There was also a significant correlation between outdoor activity duration and the sum of clinical symptoms ( P < 0.001). Neither frequency of drug use nor PNIF values were affected by the short-term changes in PM10 levels. Conclusions: Our data suggest that PM10 concentration during spring influences nasal obstruction as determined by PNIF; this nasal obstruction was also influenced by the duration of outdoor activity.