Long-term exposure of adults to outdoor air pollution is associated with increased airway obstruction and higher prevalence of bronchial hyperresponsiveness

The authors studied the association between long-term exposure (i.e., > 10 y) to outdoor air pollution and the severity of obstructive pulmonary disea se and prevalence of bronchial hyperreactivity to beta 2 agonists in two gr oups of adult patients who were of similar ages and who had similar smoking habits. The subjects lived in downtown districts or in the outer suburbs o f Marseilles, the neighborhood that contained air samplers. The regions wer e similar with respect to sulfur dioxide levels, but levels of nitric oxide s and particulate matter (10 millimeters or less) were higher in the downto wn area than the suburbs. The authors assessed airway obstruction, as deter mined by a decrease in forced expiratory volume in 1 s, mean forced expirat ory flow measured between 25% and 75% of vital capacity, and an elevated va lue of central airway resistance. The authors tested the changes in these v ariables induced by inhalation of a beta 2 agonist. Baseline lung function was altered more significantly in both male and female patients who lived i n downtown Marseilles than in those who resided in the suburbs, and the dif ferences persisted regardless of the season during which the study occurred . Prevalence of bronchial hyperreactivity and symptoms of asthma (but not o f rhinitis) were higher in the downtown than suburban male subjects. The re sults of this study suggest that an association exists between actual envir onmental exposure to outdoor air pollution (i.e., nitrogen oxides and/or pa rticulate matter of 10 millimeters or less) and respiratory effects in sens itive adults represented by patients with chronic obstructive pulmonary dis ease or asthma.