Short-Term Effects of Carbonaceous Components in PM 2.5 on Pulmonary Function: A Panel Study of 37 Chinese Healthy Adults.

Objectives: To explore the health effects of indoor/outdoor carbonaceous compositions in PM _2.5 on pulmonary function among healthy students living in the local university campus.
Methods: Daily peak expiratory flow (PEF) and forced expiratory volume in 1 second (FEV ₁ ) were measured among 37 healthy students in the morning and evening for four two-week periods. Concurrent concentrations of indoor and outdoor PM _2.5 (particulate matter with an aerodynamic diameter ≤ 2.5μm), carbonaceous components in PM _2.5 , ambient temperature, and relative humidity in the study area were also obtained. Mixed-effects model was applied to evaluate the associations between carbonaceous components and lung function. Different lags for the carbonaceous components were investigated.
Results: In single-pollutant model, a 10 μg/m ³ increase of indoor and outdoor EC (elemental carbon) associated with -3.93 (95% CI : -6.89, -0.97) L/min and -3.21 (95% CI : -5.67, -0.75) L/min change in evening PEF at lag 0 day, respectively. Also, a 10 μg/m ³ increase of indoor and outdoor POC (primary organic carbon) concentration was significantly associated with -5.82 (95% CI : -10.82, -0.81) L/min and -7.32 (95% CI : -12.93, -1.71) L/min change of evening PEF at lag 0 day. After adjusting total mass of PM _2.5 , indoor EC consistently had a significant adverse impact on evening PEF and FEV ₁ at lag3 day and a cumulative effect at lag0-3 day.
Conclusions: This study suggests that carbonaceous components in PM _2.5 indeed have impacts on pulmonary function among healthy young adults especially on evening PEF. Thus, the local mitigation strategies on pollution are needed.