Proximity to Industrial Food Animal Production and Asthma Exacerbations in Pennsylvania, 2005-2012

Abstract

The research on industrial food animal production (IFAP) and asthma exacerbations in the United States has relied on small sample sizes and/or self-reported outcomes. We assessed associations of proximity to large-scale and densely stocked swine and dairy/veal IFAP with three types of asthma exacerbations: hospitalizations, emergency encounters, and oral corticosteroid (OCS) medication orders from Geisinger Clinic in Pennsylvania. We used a diagnosis code (International Classification of Diseases, 9th Revision, Clinical Modification code 493.x) and medication orders from electronic health records to identify these exacerbations among asthma patients (n = 35,269) from 2005-2012. We compared residential proximity to swine or dairy/veal IFAP (dichotomized as <3 miles (4.8 km) or ≥3 miles) among asthma patients with and without exacerbations and estimated odds ratios using multilevel logistic regression. In adjusted models, proximity to IFAP was associated (odds ratio (95% confidence interval)) with OCS orders (1.11 (1.04-1.19)) and hospitalizations (1.29 (1.15-1.46)), but not emergency encounters (1.12 (0.91-1.37)). This study contributes to growing evidence that IFAP may impact health, in this case clinically-documented asthma exacerbations. No prior study has evaluated the association of IFAP and clinically-documented asthma exacerbations in the United States.

Keywords: asthma; asthma exacerbation; concentrated animal feeding operation (CAFO).

Figure 1

The location of swine and dairy/veal industrial food animal production facilities and the residential location of Geisinger Clinic asthma patients.