北京市PM_2.5和PM₁₀对中老年人肺功能短期效应的定组研究

[Objective] China is one of the countries with the worst air particulate pollution in the world, and lung is the target organ of such pollution. This paper is designed to study the short-term effects of PM_2.5 and PM₁₀ on lung function among middle-aged and elderly residents. [Methods] A total of 36 volunteers aged 50 to 70 years were recruited from a community in Beijing. Their peak expiratory flow rate (PEFR) was measured three times a day for consecutive 30 days as an index of lung function; daily average atmospheric PM_2.5 and PM₁₀ concentrations were retrieved from nearby air quality monitoring stations, and temperature was retrieved from Beijing Meteorological Service; other basic information of the subjects was collected through questionnaires. The effects of exposure to PM_2.5 and PM₁₀ within 0-3 days on PEFR in the middle-aged and elderly residents were estimated by linear mixed-effect models, adjusting for long-term trends, day-of-the-week effects, mean temperature, and individual random effects. [Results] The short-term effects of PM₁₀ on PEFR were not statistically significant within 0-3 lag days (P > 0.05). Each 10 μg/m³ increase in PM_2.5 concentration on the same day and 1, 2, or 3 days prior to PEFR measurement was associated with 0.370, 0.248, 0.333, and 0.334 L/min of PEFR reduction, respectively, all with statistical significance (P < 0.05). The moving average of PM_2.5 concentration from the day of measurement to previous 3 days showed the strongest effect, with PEFR decreasing by 0.592 L/min (P < 0.001) for each 10 μg/m³ increase in PM_2.5 concentration. The subgroup analysis results showed stronger effects in males and people with higher educational level, of normal body mass index, traveling by bus, subway, or car, and with smoking history, and the interaction effects were all statistically significant (P < 0.05). [Conclusion] Among the middle-aged and elderly people, short-term exposure to PM_2.5 within 0-3 days can cause damage to respiratory health, and males and people with higher educational level, of normal body mass index, traveling by bus, subway, or car, and with smoking history are more vulnerable to the effect of PM_2.5. PM₁₀ has no obvious short-term effects.