Long-term effects of traffic particles on lung function decline in the elderly.

RATIONALE: Few studies have been performed on air pollution effects on lung function in the elderly, a vulnerable population with low reserve capacity, and even fewer have looked at changes in the rate of lung function decline.
OBJECTIVES: We evaluated the effect of long-term exposure to black carbon on levels and rates of decline in lung function in the elderly.
METHODS: FVC and FEV1 were measured one to six times during the period 1995-2011 in 858 men participating in the Normative Aging Study. Exposure to black carbon, a tracer of traffic emissions, was estimated by a spatiotemporal land use regression model. We investigated the effects of moving averages of black carbon of 1-5 years before the lung function measurement using linear mixed models.
MEASUREMENTS AND MAIN RESULTS: A 0.5 μg/m(3) increase in long-term exposure to black carbon was associated with an additional rate of decline in FVC and FEV1 of between 0.5% and 0.9% per year, respectively, depending on the averaging time. In addition, black carbon exposure before the baseline visit was associated with lower levels of both FVC and FEV1, with effect estimates increasing up to 6-7% with a 5-year average exposure.
CONCLUSIONS: Our results support adverse effects of long-term exposure to traffic particles on lung function level and rate of decline in the elderly and suggest that functionally significant differences in health and risk of disability occur below the annual Environmental Protection Agency National Air Quality Standards.