Study On The Characteristic And Health Risk Of Suspended Particles Matters(PMs)-bound Heavy Metals In Indoor Environment Of Coal-mining Cities In Winter

Many studies have been found that the impact of coal on human health is reflected in two links:One is deaths which caused by the process of coal production and occupational injuries.And the other is air pollution caused by coal consumption,especially suspended particulates and their attached toxic and harmful substances（such as heavy metals）.Therefore,it is of great significant to study the sources of suspended particles in the indoor and outdoor environments of coal mining cities,the characteristics of heavy metals pollution in suspended particles and the health risks that they may cause people injured.This paper analyzed the indoor and outdoor environmental suspended particulate matter(PM₁₀)in winter in coal mining cities in northern country（Jixi,Hegang,Shuangyashan,and Qitaihe）and the indoor and outdoor environmental suspended particulate matter（funnel soot,coal fired-ash,coal power）in southwestern coal mining cities（Xuanwei）to conduct research:（1）Based on the winter outdoor environment PM₁₀is the main source of indoor environment PM₁₀,the chemical balance model（CMB）was used to analyze the source of PM₁₀;（2）Based on the quantitative assessment method of biologically available concentration combined with health risks.The evaluation model was analyzed the health risk of heavy metals in suspended particulates,and provided new ideas for the health risk assessment of urban suspended particulates.The main conclusions of this study include:（1）The first major pollution source of PM₁₀ was coal-burning sources,the second largest pollution source was motor vehicles,and the third largest pollution source was open source.（2）The total concentrations of PM₁₀ heavy metals in the indoor environment of coal mining cities in the north were（ng/m³）:Hegang:Pb（0.027）>As（0.015）>Cd（0.014）;Shuangyashan:Cd（0.198）>Pb（0.028）>As（0.009）;Jixi:Cd（0.015）>Pb（0.015）>As（0.004）;Qitaihe:Pb（0.060）>Cd（0.031）>As（0.010）.The total concentrations of suspended particulate heavy metals in the coal mining city（Xuanwei）in Southwest China were（ng/mg）:Chimney ash:Mn（642.58）>Pb（279.74）>Cd（25.22）;coal ash:Mn（900.50）>Pb（149.41）>Cd（5.51）;coal ash:Mn（1710.71）>Pb（8.59）>Cd（0.33）.（3）The bioavailable concentration and bioavailability of suspended particulate heavy metals in acidic lung fluid were higher than those in neutral lung fluid.（4）In northern regions,the non-carcinogenic risks of heavy metals in indoor suspended particulate matter in city areas in winter were lower than the health risk threshold,and the carcinogenic health risk of As and Cd exceeds the threshold(Hegang:As,5.88×10^-6;Cd,1.43×10^-6.Shuangyashan:As,4.83×10^-6;Cd,1.65×10^-5.Jixi:As,6.90×10^-6;Cd,1.47×10^-6.Qitaihe:As,3.06×10^-6;Cd,3.66×10^-6).In Southwest China,the carcinogenic and non-carcinogenic risks of heavy metals in indoor suspended particulate matter（30-38μm）in city areas in winter were both lower than the health risk threshold.The value of HI was:man:1.31×10^-3;woman:1.11×10^-3;child:1.43×10^-3.The numerical value of HI from high to low was HI（child）>HI（man）>HI（woman）.