Lifelong exposure to air pollution and greenness in relation to asthma, rhinitis and lung function in adulthood.

OBJECTIVES

To investigate if air pollution and greenness exposure from birth till adulthood affects adult asthma, rhinitis and lung function.

METHODS

We analysed data from 3428 participants (mean age 28) in the RHINESSA study in Norway and Sweden. Individual mean annual residential exposures to nitrogen dioxide (NO), particulate matter (PM and PM), black carbon (BC), ozone (O) and greenness (normalized difference vegetation index (NDVI)) were averaged across susceptibility windows (0-10 years, 10-18 years, lifetime, adulthood (year before study participation)) and analysed in relation to physician diagnosed asthma (ever/allergic/non-allergic), asthma attack last 12 months, current rhinitis and low lung function (lower limit of normal (LLN), z-scores of forced expiratory volume in one second (FEV), forced vital capacity (FVC) and FEV/FVC below 1.64). We performed logistic regression for asthma attack, rhinitis and LLN lung function (clustered with family and study centre), and conditional logistic regression with a matched case-control design for ever/allergic/non-allergic asthma. Multivariable models were adjusted for parental asthma and education.

RESULTS

Childhood, adolescence and adult exposure to NO, PM and O were associated with an increased risk of asthma attacks (ORs between 1.29 and 2.25), but not with physician diagnosed asthma. For rhinitis, adulthood exposures seemed to be most important. Childhood and adolescence exposures to PM and O were associated with lower lung function, in particular FEV (range ORs 2.65 to 4.21). No associations between NDVI and asthma or rhinitis were revealed, but increased NDVI was associated with lower FEV and FVC in all susceptibility windows (range ORs 1.39 to 1.74).

CONCLUSIONS

Air pollution exposures in childhood, adolescence and adulthood were associated with increased risk of asthma attacks, rhinitis and low lung function in adulthood. Greenness was not associated with asthma or rhinitis, but was a risk factor for low lung function.