Air pollution from livestock farms is associated with airway obstruction in neighboring residents

Rationale: Livestock farm emissions may not only affect respiratory health of farmers but also of neighboring residents. Objectives: To explore associations between spatial and temporal variation in pollutant emissions from livestock farms and lung function in a general, nonfarming, rural population in the Netherlands. Methods: We conducted a cross-sectional study in 2,308 adults (age, 20-72 yr). A pulmonary function test was performed measuring prebronchodilator and post-bronchodilator FEV₁, FVC, FEV₁/FVC, and maximum mid-expiratory flow (MMEF). Spatial exposure was assessed as (1) number of farms within 500 m and 1,000 m of the home, (2) distance to the nearest farm, and (3) modeled annual average fine dust emissions from farms within 500 m and 1,000 m of the home address. Temporal exposure was assessed as week-average ambient particulate matter,10 μm in diameter and ammonia (NH₃) concentrations before lung function measurements. Data were analyzed with generalized additive models (smoothing). Measurements and Main Results: A negative association was found between the number of livestock farms within a 1,000-m buffer from the home address and MMEF, which was more pronounced in participants without atopy. No associations were found with other spatial exposure variables. Week-average particulate matter,10 μm in diameter and NH3 levels were negatively associated with FEV₁, FEV₁/FVC, and MMEF. In a two-pollutant model, only NH₃ remained associated. A 25-mg/m³ increase in NH₃ was associated with a 2.22% lower FEV₁ (95% confidence interval, 23.69 to 20.74), FEV₁/FVC of 21.12% (21.96 to 20.28), and MMEF of 25.67% (28.80 to 22.55). Conclusions: Spatial and temporal variation in livestock air pollution emissions are associated with lung function deficits in nonfarming residents.