| With the acceleration of industrialization and urbanization,air pollution in developed countries has been a problem for more than 100 years,and has occurred frequently in China's economically developed areas in the past thirty years.The air quality situation was worrying.Fine particulate matter(PM2.5)was one of the most important air pollutants in China,and it was also one of the main bottlenecks to improve the air quality.At present,research on coal-fired sources mainly focuses on the components and emission factors of particulate matter emitted from coal combustion,and little research has been done on their effects on human health,it was very important to analyze the health risk of ambient air particulate matter,so it was important to evaluate the human cytotoxicity of particulate matter emitted from coal combustion.Based on the analysis of ambient air PM2.5 and human lung cytotoxicity in different function areas of Nanjing,it was found that coal combustion was one of the main anthropogenic sources of PM2.5 in cities,further study on the impact of particulate matter emitted from coal combustion on human health.A total of 4 types of 10 kinds of coal,including honeycomb briquette,anthracite,bituminous coal and industrial coal,were selected as research objects,the coal combustion emission particulates(PM2.5,PM10)were collected by dilution channel sampling system,and the contents of carbon components,metal elements and water-soluble ions were analyzed,the survival rate of human lung epithelial cells A549,the level of oxidative stress index and the expression of inflammatory factors were measured,the correlation between organic carbon OC,elemental carbon EC,metal elements and water-soluble ions and their cytotoxicity was evaluated.The results were as follows:(1)PM2.5 pollution level in Nanjing was higher in winter,and it was influenced by the weather condition.The concentration of PM2.5 was negatively correlated with wind speed and visibility,and the correlation coefficient was high.Snowfall can effectively improve the influence of human activities on PM2.5,and can also change the composition of PM2.5.Heavy metals and water-soluble ions in urban PM2.5 were higher than those before and after snowfall,therefore,PM2.5 was more cytotoxic and genotoxic than PM2.5 before snowfall,and has the ability to induce oxidative damage and inflammatory damage.Combined with the chemical composition and source analysis of PM2.5,it was found that heavy metals and water-soluble cations produced by coal combustion were toxic to PM2.5 cells.(2)The chemical composition characteristics of particulate matter emissions from different types of coal combustion were different in different regions.The concentration of carbon components from the combustion of honeycomb briquette and anthracite is the lowest,and bituminous coal was higher than industrial coal.OC and EC were the main components of particulate matter from the combustion of bituminous coal.SO42-,NO3-and NH4+were dominant in PM2.5,Cl-,SO42-and Na+were dominant in PM10.SO42-and NH4+were the main components in the particulate matter of honeycomb briquette,anthracite and industrial coal.Na and Ca were the main metal elements emitted from coal combustion,while Zn and Pb were the dominant heavy metal elements emitted from coal combustion.(3)the cytotoxicity of particulate matter from coal combustion was related to the size and type of particulate matter.The effect of fine particulate matter PM2.5 emitted from coal combustion on cell viability was slightly greater than that of PM10.Industrial coal has the strongest ability to induce oxidative stress and inflammatory damage in cells.In bituminous coal and industrial coal,IL-6 and TNF-?were mainly induced by cells,while honeycomb briquette and anthracite had similar ability of IL-6 and TNF-?.The particulate matter PM2.5from coal combustion was mainly composed of metal elements and PM10 was mainly composed of water-soluble ions. |
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