The Relative Contributions of Different Chemical Components to the Oxidative Potential of Ambient Fine Particles in Nanjing Area.

Xiaoyun Ma,Dongyang Nie,Zhirao Li,Zhengjiang Liu,Pengxiang Ge,Rui Gu,Xinlei Ge,Mindong Chen

doi:10.3390/ijerph18062789

Abstract

Ambient fine particles (PM2.5) have been shown to have adverse health effects by inducing oxidative stress. Here, dithiothreitol (DTT)-based oxidative potential (OP) was used to assess the capacity of oxidative stress caused by PM2.5. In this study, PM2.5 samples were collected in the Nanjing area in 2016, and physicochemical properties and DTT activity were investigated. The annual mean PM2.5 mass concentration was 73 μg m−3 and greatly varied among seasons (spring > winter > summer > autumn). Three fluorescent substances were identified by the excitation-emission matrix (EEM) spectrum. The annual mean mass-normalized DTT activity (DTTm; 0.02 nmol min−1 μg−1) was similar to that documented for cities of some developed countries. The annual mean volume-normalized DTT activity (DTTv) showed a relatively high value of 1.16 nmol min−1 m−3, and the seasonal mean DTTv was highest in winter, followed by spring, autumn, and summer, whose pattern is different from PM2.5 mass concentration. Correlation and multiple linear regression analysis suggested that transition metals may have a greater effect on OP in autumn and winter, humic-like substances and UV absorbing aromatic substances may have a strong effect on OP in spring and summer. Generally, this study enhances our understanding of seasonal variation in health effects associated with PM2.5.

Highlights

IntroductionAtmospheric fine particles (diameter ≤ 2.5 μm, PM2.5 ) have affected air quality and human health in China for years [1]
Atmospheric fine particles have affected air quality and human health in China for years [1]
Exposure to ambient particulate matter induces the production of reactive oxygen species (ROS) in biological systems, including superoxide anions (·O2 − ), hydroperoxides (·HO2 ), and hydroxyl radicals (·OH), and these ROS are the main cause of the adverse health effects

Summary

Introduction

Atmospheric fine particles (diameter ≤ 2.5 μm, PM2.5 ) have affected air quality and human health in China for years [1]. Recent studies have found that disease such as cardiovascular disease [2,3], respiratory disease [4], mental stress, and premature death are associated with atmospheric fine particulate matter [5]. Exposure to ambient particulate matter induces the production of reactive oxygen species (ROS) in biological systems, including superoxide anions (·O2 − ), hydroperoxides (·HO2 ), and hydroxyl radicals (·OH), and these ROS are the main cause of the adverse health effects. Excess ROS disrupts the redox state, causing oxidative stress (OS) and leading to cell apoptosis, biological senescence, and various diseases [6,7]. The ability of particulate matter to induce the production of ROS in organisms is called oxidative potential (OP). Methods of assessing the OP of particulate matter are divided into two categories: cellular and acellular methods

Methods

Results

Conclusion