Long-term exposure to particular matter (PM), especially fine PM (< 2.5 μm in the aerodynamic diameter, PM2.5), is associated with increased risk of cardiovascular disorders. This study aimed to evaluate the association between long-term exposure to PM2.5/PM10 and the metabolic change in the plasma. Specifically, using metabolomics, we sought to identify the biomarkers for the vulnerable subgroup to PM2.5 exposure. A total of 78 college student volunteers were recruited into this prospective cohort study. All participants received 8 rounds of physical examinations at twice quarterly. Air purifiers were placed in 40 of 78 participants’ dormitories for 14 days. Before and after intervention, physical examinations were performed and the peripheral blood was collected. Plasma metabolomics was determined by ultra-performance liquid chromatography-mass spectrometry. During the follow-up, the average concentrations of PM2.5 and PM10 were 53 μg/m3 and 93 μg/m3, respectively. Totally, 42 and 120 differential metabolic features were detected for PM10 and PM2.5 exposure, respectively. In total, 25 differential metabolites were identified for PM2.5 exposure, most of which were phospholipids. No distinctive metabolites were found for PM10 exposure. A total of 6 differential metabolites (lysoPC (P-20:0), lysoPC (P-18:1(9z)), lysoPC (20:1), lysoPC (O-16:0), choline, and found 1,3-diphenylprop-2-en-1-one) were characterized and confirmed for sensitive individuals. Importantly, we found LysoPC (P-20:0) and LysoPC (P-18:1(9z)) changed significantly before and after air purifier intervention. Our results indicated that the phospholipid catabolism was involved in long-term PM2.5 exposure. LysoPC (P-20:0) and LysoPC (P-18:1(9z)) may be the biomarkers of PM2.5 exposure.
This study investigated the particulate matter (PM) and metals in highway dry deposition and rainfall-runoff as a function of hydrologic transport and settling on an event basis. Events were differentiated as mass-limited (ML) and flow-limited (FL). Results indicate that unique and separate suspended sediment concentration (SSC) relationships with turbidity occurred for ML and FL events. Sixty minutes of quiescent settling produced a single SSC-turbidity relationship for all events. ML events transport higher proportions of settleable and sediment PM while FL events transported relatively higher suspended PM. For batch clarification with one hour of settling, ML events had generally higher treatment efficiencies compared to FL events for the same settling conditions. Highway dry deposition PM was hetero-disperse and coarse (d50 m = 304 μm). Results indicate that the acidic rainfall is not a significant contributor to metals in runoff but is capable of leaching metals from dry deposition PM into runoff. Partitioning in retained runoff resulted in a particulate-bound predominance for most metals except Ca and Mg. While the finer fraction of dry deposition PM (< 75 μm) generates the highest metal concentrations, the highest metal mass is associated with the coarser fraction (> 75 μm). 相似文献