The Effects of Different Levels of Air Pollution on Atopy and Symptoms of Allergic Rhinitis

Abstract

We evaluated the prevalence of symptoms of allergic rhinitis and atopy among two groups living in areas with different pollution levels. The study was conducted among high school students living in Bayrampa§a (polluted by SO2 and TSP) and Beykoz (unpolluted, residental area) in Istanbul (n = 386). Each subject filled out a standardized self-administered questionnaire. Atopic status was evaluated by skin-prick testing using eight different allergens. Also, anterior active rhinomanometry was performed to evaluate the symptoms objectively. Significantly higher prevalence rates for symptoms of allergic rhinitis were found in Bayrampaşa (22.8%) compared to Beykoz (6%). However, no significant difference was found for atopic status among the two groups. When we evaluated the atopic status of subjects with symptoms of allergic rhinitis between the two areas, the prevalence of atopic students was found to be relatively higher in the unpolluted area (BZ). This difference was not statistically significant. Within the atopic population, subjects complaining of symptoms of allergic rhinitis were significantly more frequent in the polluted area (BP), suggesting that air pollution causes an increase in symptoms of allergic rhinitis in the atopic population, but this is not significantly higher than the increase in symptoms of allergic rhinitis of the total study group. Our results suggest that pollutants exert irritant effects on mucous membranes of the population in general rather than aggrevating symptoms in predisposed individuals. Smoking was more frequent in the unpolluted area. Exposure to parental smoking in childhood and heating systems in houses were evenly distributed. Household crowding was lower in Beykoz. Rhinomanometric measurements among the two groups did not show significant difference. Multiple logistic regression models estimating the role of each risk factor independently showed significant odds ratio associated with residence in Bayrampaşa for symptoms of allergic rhinitis (OR = 4.6, 95% CI = 9.0–2.3). In conclusion, this study suggests that outdoor pollution has adverse effects on the symptoms of allergic rhinitis, while it has no effect on the prevalence of atopy in Istanbul in the 1990s.