Abstract

Background: Daily variations in ambient particulate air pollution have been associated with respiratory mortality and morbidity.

Aims: To assess the associations between urinary concentration of lung Clara cell protein CC16, a marker for lung damage, and daily variation in fine and ultrafine particulate air pollution.

Methods: Spot urinary samples (n = 1249) were collected biweekly for six months in subjects with coronary heart disease in Amsterdam, Netherlands (n = 37), Erfurt, Germany (n = 47), and Helsinki, Finland (n = 47). Ambient particulate air pollution was monitored at a central site in each city.

Results: The mean 24 hour number concentration of ultrafine particles was 17.3×10³ cm⁻³ in Amsterdam, 21.1×10³ cm⁻³ in Erfurt, and 17.0×10³ cm⁻³ in Helsinki. The mean 24 hour PM_2.5 concentrations were 20, 23, and 13 μg/m³, respectively. Daily variation in ultrafine particle levels was not associated with CC16. In contrast, CC16 concentration seemed to increase with increasing levels of PM_2.5 in Helsinki, especially among subjects with lung disorders. No clear associations were observed in Amsterdam and Erfurt. In Helsinki, the CC16 concentration increased by 20.2% (95% CI 6.9 to 33.5) per 10 μg/m³ increase in PM_2.5 concentration (lag 2). The respective pooled effect estimate was 2.1% (95% CI −1.3 to 5.6).

Conclusion: The results suggest that exposure to particulate air pollution may lead to increased epithelial barrier permeability in lungs.