Personal Exposure To PM2.5 (And Their Constituents) And Inflammatory Responses In Healthy Young Adults

Abstract

Introduction: Fine particles (PM2.5) are associated with inflammation-related diseases and its toxicity changes with its composition. Therefore, the Identification of components with corresponding adverse health effects is important for effective air pollution control strategies. Several PM constituents such as black carbon, organic carbon, polycyclic aromatic hydrocarbons and phthalate esters have received much attention in the past and demonstrated potential of causing respiratory illness, while there are limited information about their associations with inflammation in healthy adults. Among the previous studies tried to examine the association, outdoor ambient concentrations were mostly used for PM2.5 exposure assessment, in stark contrast to the fact that young adults typically spend vast majority of their time in indoor environments. Characterizing personal exposure to PM2.5 and their chemical constituents is essential for accurate exposure assessment. Methods: The current study involves with 50 healthy young adults recruited from different districts of Hong Kong to undergo daily active personal PM2.5 monitoring (24 hours) in 6 consecutive days during summer and winter, respectively. At the end of each personal sampling day, exhaled nitric oxide was monitored and exhaled breath condensates along with urine samples were collected for biomarker monitoring. Personal activities and respiratory symptoms of all the subjects were recorded by self-reported diaries to check for health status and potential health influencing factors. Mixed effects model controlling for confounders was adopted to estimate the associations between repeated measurements of personal PM2.5 exposure and inflammatory biomarkers. Results: Preliminary result of summer season featured that PM2.5 was significantly associated with FeNO levels (p