Toxicological Assessments and Those Prescriptive Factors of PM_2.5 in Saitama Prefecture Using Year-Round Ambient Samples

Abstract

Fine particulate matters with a diameter of <2.5 µm (PM_2.5) adversely affect the respiratory and immune systems. However, the contributing factors to its health effects remain unclear due to the variety of the PM_2.5 components depending on the season and source. We aimed to investigate the differences in the effects of PM_2.5 extracts collected from Saitama during the different seasons on the respiratory and immune systems and to clarify the contributing factors to health effects of PM_2.5. PM_2.5 were collected by a filter at the Center for Environmental Science in Saitama (Kazo City, Saitama Prefecture) from April 2013 to March 2018 and were divided into aqueous and organic extracts. Chemical analyses revealed that the aqueous components in the autumn were significantly affected by open burning. The aqueous components of PM_2.5 caused a pro-inflammatory response, such as IL-6 release from antigen-presenting cells. The effects varied depending on the season, especially in the autumn. OC4 in PM_2.5 showed the highest positive correlation with the IL-6 release from antigen-presenting cells. These results suggest that the PM_2.5 aqueous components derived from open burning can cause a pro-inflammatory effect in antigen-presenting cells.