Short-term air pollution exposure decreases lung function: a repeated measures study in healthy adults.

Background: Daily changes in ambient concentrations of particulate matter, nitrogen oxides and ozone are associated with increased cardiopulmonary morbidity and mortality, with the lungs and their function being a vulnerable target.

Methods: To evaluate the association between daily changes in air pollution and lung function in healthy adults we obtained annual lung function measurements from a routine worker health surveillance program not designed for research purposes. Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), FEV1/FVC and Peak Expiratory flow (PEF) from a cohort of 2449 employees were associated with daily measurements of PM, NO and ozone at a nearby monitoring station in the North of Belgium. Repeated measures were available for the period 2011-2015.

Results: The mean (SD) PM concentration on the day of the lung function test was 24.9 (15.5) μg/m. A 10 μg PM/m increase on the day of the clinical examination was associated with a 18.9 ml lower FVC (95% CI: -27.5 to -10.3, p < 0.0001), 12.8 ml lower FEV1 (-19.1 to -6.5; p < 0.0001), and a 51.4 ml/s lower PEF (-75.0 to -27.0; p < 0.0001). The FEV1/FVC-ratio showed no associations. An increase of 10 μgNO/m was associated with a reduction in PEF (-66.1 ml/s (-106.6 to -25.6; p < 0.001)) on the day of the examination.

Conclusions: We found negative associations between daily variations in ambient air pollution and FVC, FEV1 and PEF in healthy adults.