Abstract:
Objectve China is one of the countries with the worst air partculate polluton in the world, and lung is the target organ of such polluton. This paper is designed to study the short-term effects of PM2.5 and PM10 on lung functon 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 tmes a day for consecutve 30 days as an index of lung functon; daily average atmospheric PM2.5 and PM10 concentratons were retrieved from nearby air quality monitoring statons, and temperature was retrieved from Beijing Meteorological Service; other basic information of the subjects was collected through questonnaires. The effects of exposure to PM2.5 and PM10 within 0-3 days on PEFR in the middleaged and elderly residents were estmated by linear mixed-effect models, adjustng 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 statstcally signifcant within 0-3 lag days (P>0.05). Each 10 μg/m3 increase in PM2.5 concentraton 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 PM2.5 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 PM2.5 concentraton. The subgroup analysis results showed stronger effects in males and people with higher educatonal level, of normal body mass index, traveling by bus, subway, or car, and with smoking history, and the interacton effects were all statstcally signifcant (P < 0.05).
Conclusion Among the middle-aged and elderly people, short-term exposure to PM2.5 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 PM2.5. PM10 has no obvious short-term effects.