Childhood Asthma in Rural-Urban Areas. Final Report.

摘要

Asthma is one of the leading causes of chronic illness among children and the most commonly reported cause of childhood disability. Rates of childhood asthma in the US have been increasing over the last several decades such that the rise in asthma prevalence has been labeled as an epidemic. The causes of this increase are not well known but may be related to factors such as increased impact of environmental allergens, indoor and outdoor air pollutants, increased obesity rates, and inadequate early immune system exposures. Research specific to prevalence of asthma among rural children is limited and has resulted in conflicting findings which may reflect differences in exposures across different types of rural settings. In some studies, rural children had lower asthma prevalence than urban counterparts. All rural environments are not the same, however, as another study found that 5% of rural children in Canada who lived in farm environments had asthma, whereas rural children who did not live in farm environments had a higher asthma prevalence rate at 9%. Urbanization may increase asthma rates and symptoms due to higher levels of air pollutants, but asthma may also be triggered by crop allergens, weeds and wildflowers, biomass smoke, dust, and animal dander, which are more prevalent in some rural settings. Research has found lower asthma rates among farm children compared to urban children, but higher rates among farm children exposed to certain activities such as hog production. Some research suggests that families who live in rural environments develop a level of immunity to plant and animal allergens that are typically associated with asthma, although other research suggests that urban exposures are key and that lower asthma rates in rural areas reflect lower urban-related risks rather than a rural protective effect. The current study assesses rates of lifetime and current asthma for children across the rural-urban continuum for the U.S. The study examines how asthma may be related to rural areas adjacent or non-adjacent to urban areas to variation in measures of air quality, to varying levels of agricultural and animal production, and to other characteristics such as obesity, race/ethnicity, or health insurance.