Diurnal variation in the proinflammatory activity of urban fine particulate matter (PM _2.5) by in vitro assays.

ABSTRACT: Background: Ambient particulate matter (PM) smaller than 2.5 µm in diameter (PM _2.5) undergoes diurnal changes in chemical composition due to photochemical oxidation. In this study we examine the relationships between oxidative activity and inflammatory responses associated with these diurnal chemical changes. Because secondary PM contains a higher fraction of oxidized PM species, we hypothesized that PM _2.5 collected during afternoon hours would induce a greater inflammatory response than primary, morning PM _2.5. Methods: Time-integrated aqueous slurry samples of ambient PM _2.5 were collected using a direct aerosol-into-liquid collection system during defined morning and afternoon time periods. PM _2.5 samples were collec

SUBMITTER: Lovett C 

PROVIDER: S-EPMC6171724 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature