The role of farm operational and rural environments as potential risk factors for pediatric asthma in rural Saskatchewan.

BACKGROUND: Researchers have historically reported that farm children have a lower prevalence of asthma compared to more urban children. Potential explanations include theories surrounding differences in personal factors, access to health care, engagement in health risk behaviors, and differences in the environment.
OBJECTIVE: The aims of this study were to: (1) confirm whether the prevalence of asthma varies between farm and small town status among children living in Saskatchewan; (2) identify risk and protective factors for asthma, and use this information to infer which of the above theories is most explanatory for any observed geographic variations in pediatric asthma.
METHODS: Rural students (N = 2383, 42% participation rate) from the province of Saskatchewan participated in a 2011 cross-sectional study. Parents completed a survey that included questions about location of residence, respiratory symptoms, potential risk factors for respiratory disease, and exposures to farm activities. Multiple logistic regression was used to examine relations between respiratory outcomes (asthma, wheeze) with farm type and farm activities, while accounting for factors that may underlie such relations.
RESULTS: Asthma and wheeze prevalence did not differ by residential status. Living on a grain farm (OR = 0.64, 95% CI = 0.43-0.96), cleaning or playing in pens (OR = 0.69, 95% CI = 0.46-1.02), filling grain bins (OR = 0.56, 95% CI = 0.32-0.96), and riding horses (OR = 0.65, 95% CI = 0.40-1.05) were protective factors for ever diagnosis with asthma.
CONCLUSIONS: We identified a number of risk and protective factors for asthma and associated wheeze. This suggests the need to focus on specific environmental explanations to better understand previously observed associations between farm residential status and asthma.