Exhalation metabolomics: A new force in revealing the impact of ozone pollution on respiratory health
Chen Tao, Peter Mettke, Yaru Wang, Xue Li, Ligang Hu
Abstract
Ozone (O3) is mainly distributed in the stratosphere of the atmosphere, with relatively low concentrations near the ground, but it has profound implications for climate change, ecological environment, and human health. Research on the spatial and temporal variation characteristics of near-ground O3 and its precursors, as well as qualitative correlation analysis and model simulation on short-term scales, have shown that the concentration of near-ground O3 has strong seasonal variations and spatial agglomeration characteristics [1]. From the perspective of the temporal variation of near-surface O3 and its precursor concentrations, in the winter half year, the precursor accumulation is not conducive to the formation of O3 through photochemical reactions due to low temperatures and weak radiation, while the opposite is true in the summer half year, especially when the sunshine duration is long, the radiation is strong, the temperature is high, and photochemical reactions are active. Meteorological conditions are conducive to the conversion of nitrogen oxides (NOx) and volatile organic compounds (VOCs) and other precursors of O3 into secondary products O3 through photochemical reactions [2]. In addition to meteorological conditions, there are many factors that affect near-surface O3 levels, including geographical location, atmospheric diffusion, and local source emissions, which jointly affect the relative proportion and abundance of O3 precursors such as NOx and VOCs [3]. The increase in near-ground O3 content is mainly due to human activities, such as vehicle exhaust from transportation, waste gas from petrochemical production, coal-fired power generation, and other biomass combustion, which emit VOCs and NOx into the atmosphere.