The Effect Of PM2.5 Exposure On Mercapturic Acid Of Healthy People

Objective:This study aimed to identify the potential biomarkers that could reflect the change of PM2.5 levels from Iow(<10ug/m3) to high (>150ug/m3) exposure on healthy volunteers.Method:We enrolled 100 young healthy volunteers (18 to 27 years old) without smoking history, and half of them randomized to the experiment on 7/26/2015 (summer group), while the other half randomized to the experiment on 12/7/2015 (winter group). A portable FA air purifier equipped with ULPA filters was selected to be the intervention to get the low PM2.5 level purified air. The high level of PM2.5 exposure were marked by PM2.5>150ug/m3 according to China Meteorological Administration Official Website and experiment PM2.5 level were further recorded by Dylos air quality monitor. In order to remove the contamination from other resources, only the distilled water and Abbott ensure complete were provided. We collected volunteers’urine at 8A.M.(empty stomach),12P.M.,3P.M. and 7P.M.. Between 8A.M. to 12P.M. and 3P.M. to 7P.M., all volunteers were required to equip FA (portable air purifying equipment), while between 12P.M. to 3P.M., they were required to expose in the high PM2.5. The amout of five mercapturic acids (included CEMA, HEMA, SPMA, HPMA and HMPMA) in urine were tested by on-line SPE-LC-MS/MS method. We used EXCEL for test results record and IBM SPSS statistics 23 for statistical analysis to explore different level of target substances in urine.Result:Only the level of HPMA and SPMA out of the five mercapturic acids at 8A.M. and 12P.M. showed statistically different (P<0.05). All five mercapturic acids showed a trend of declining. All target substances level (include summer group and winter group) at 8A.M. and 3P.M. showed statistically significant different (P<0.05). No consistent change showed over time from 12P.M. to 3P.M..Conclusion:HPMA and SPMA could be selected as the alternatives reflecting the change of PM2.5 air exposure among healthy volunteers. Drink and diet restriction is necessary for the experiment. FA is quite satisfactory tool to ensure clean air intake. Further research need focus on the exposure time window shift to better understand health effect of polluted air on human.