Current pet ownership modifies the adverse association between long-term ambient air pollution exposure and childhood asthma

Abstract

BACKGROUND: Recent studies suggest that household endotoxin and allergens can modify the impact of air pollutants on development of asthma; however, epidemiological evidence is limited and conflicting. OBJECTIVES: To investigate whether pet ownership modified the association between ambient air pollution and asthma in children. METHODS: We conducted a population-based cross-sectional study, the Seven Northeast Cities Study in China and recruited a total of 59,754 children from 94 schools during 2012-2013. Long-term air pollutant concentrations, including airborne particulate matter with a diameter of 1 μm or less (PM1 ), PM2.5 , PM10 , and nitrogen dioxide (NO2 ) from 2009 to 2012 were estim..