Abstract
As part of a panel study on medium-term effects of air pollution, we evaluated the association between exposure to PM10 and NO2 and the intra-individual changes in FEV1 and FVC. Twenty healthy volunteers aged 59 to 76 years underwent 4 health exams (n=80 observations) over 1.5 months. The first and last exams were performed in Leuven (Belgium), the other during a 10 day stay in Milan (Italy). Spirometry was done with NDD EasyOne. PM10 lag0, lag1 and the average for lag0, lag1 and lag2 (av0-2) were obtained from local monitoring stations. Personal exposure to NO2 was monitored 3 times during 5 days. We built generalised linear mixed models to obtain adjusted coefficients (β) and their 95% confidence intervals (CI), indicating a change in FEV1 or FVC (mL) per 10 μg/m³ change in PM10 or NO2. Adjusting variables were sex, age, height, weight, temperature and humidity.
In Milan, lung volumes were lower (FEV1 crude (c) β=-39 CI: -92; 14; FVC cβ=-43 CI: -102; 16), and exposure levels higher (PM10 av0-2 cβ=19 CI: 16; 21; NO2 cβ=33 CI: 31; 35). After adjustment, a 10 μg/m³ increase in av0-2 was associated with a 65 mL decline in FVC (CI:-120;-10). Interaction terms for sex and PM10 or NO2 were significant (p<0.05). Stratified analyses showed that PM10 and NO2 levels in men but not women were associated with FEV1 and FVC decline. In men, the β was lowest for FVC vs av0-2 (β=-133 CI: -214;-52), and a 10 μg/m³ increase in NO2 was associated with a 37 mL decline in FEV1 (CI: -63; -11) and 34 mL in FVC (CI: -66; -2).
Our results suggest that medium-term changes in PM10 and NO2 are associated with a decline in lung function and that sex is an effect modifier that needs to be considered in further analyses.
- © 2014 ERS
