Frequent occurrence of respiratory symptoms in children is associated with exposure to air pollution, land use types, and parental mental health in the Greater Taipei area

Although studies have investigated the individual effects of air pollution, land use types, and parental mental health on children's respiratory health, few studies have examined the effects of these risk factors simultaneously in children aged <2 years. We investigated the effects of exposure to air pollution, land use types surrounding residences, and parental mental health on the frequent occurrence of respiratory symptoms in children aged <2 years in the Greater Taipei area. Participants were recruited from an ongoing Taiwanese birth cohort study. We analyzed the data of the participants who had been recruited from January 2011 to April 2014 and had responded to the follow-up questionnaires at 6, 12, and 24 months. Self-administered questionnaires were used to collect participants' sociodemographic background and health, such as respiratory symptoms, and parental mental health. Pre- and postnatal pollution levels were estimated using the spatial interpolation technique (ordinary kriging) at children's residential addresses. Land use types surrounding participants' homes were evaluated by performing buffer analysis. Multiple logistic regression analyses were conducted to examine the effects of risk factors on the frequent occurrence of child respiratory symptoms in children aged 6, 12, and 24 months. We included 228, 360, and 441 children aged 6, 12, and 24 months, respectively. Our results indicated that postnatal exposure to PM_2.5 and O₃ was positively associated with children's respiratory symptoms. Traffic-related land-use types, sports facilities, and commercial land surrounding homes exerted adverse effects on children's respiratory symptoms, whereas the presence of schools in the neighborhood was beneficial. Parental mental health was also associated with children's respiratory symptoms. Postnatal exposure to air pollution and land use types surrounding residences were associated with respiratory health in children aged <2 years. The residential environment is a critical factor affecting children's respiratory health of children aged <2 years.