Exposure to environmental factors and relationship to allergic rhinitis and/or asthma

Studies analyzing risk factors, multiple indoor and outdoor factors related to asthma and/or allergic rhinitis (AR) in childhood, are very rare. The presented study was carried out to simultaneously assess host-related, indoor and particulate matter exposure with current allergic rhinitis (AR) and/or asthma in children (6-7 years) and adolescents (13-14 years).

The method was a cross-sectional population-based study in which participants were diagnosed by means of the International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire.

Exposure to indoor risk factors were verified in 1,302 individuals, in which the prevalence of AR, asthma and AR-asthma comorbidity were 37.3%, 28.4%, and 16%, for children and 31.5%, 16.2%, and 10.5% for adolescents, respectively. Smoking during pregnancy was associated with current asthma (OR=1.5), second-hand smoking with AR-asthma comorbidity (OR=1.4) and visible mold on the walls with current AR, asthma, and AR-asthma comorbidity (OR=1.6). In a subgroup of 590 children, in addition to the indoor risk factors, exposure to PM10 was assessed. In this joint analysis, there was association with the same previously mentioned risk factors (p values ≤ 0.5) and a negative association to PM10 (p ≤ 0.002).

The results suggest that avoidance of smoking during pregnancy, second-hand smoking and exposure to mould at home can contribute to reducing current AR and/or current asthma. Exposure to PM10 was not associated with the prevalence rate of these diseases.