| Particulate matter exist in various indoor and outdoor environment,in order to understand the pollution characteristics of indoor and outdoor inhalable particulate matter, personal exposure level to particulate matter and heavy metals health risk of school children during the school time,airborned particulate matters inside and outside were collected at the same time by Model TE-20-800 high volume and eight grading particles captor(U.S. Tisch Company) in 2014 January.The sampling school was a rural primary school located in the south of Jiaozuo city, where warmed by burning coal in the winter. The main results were listed as follows:1.The mass concentrations of different diameters of air particles were measured by gravimetric method. It was found that the distributions of outdoor inhalable particulate matters were overall of concave form. The two peak values appeared in the range of 5.8 to 10.0μm and 2.1 to 0.43μm.Indoor inhalable particle more concentrated in the fine particles, prensenting high concentration on one side and the peak values were in the range of 1.1-2.1μm.The concentration of indoor and outdoor each diameter particle varied widely in different sampling time.The outdoor particle composition of each diameter changed,while that of the indoor particle was similar in different sampling time. The concentration of fine particles was high and took a large proportion in inhalable particles.The indoor particles were mainly affected by the indoor source in teaching period daytime,while mainly affected by outdoor source during the non-teaching period.2.The mass concentration of Cr, Co, Ni, Cu, Se, Cd, Sb and Pb were measured by Inductively Coupled Plasma Mass Spectrometry(ICP-MS), then element distribution of indoor and outdoor partile and pollution source were discussed in this paper. It is found in the study that the mass concentration range of Cr, Co, Ni, Cu, Se, Cd, Sb and Pb in indoor particle were respectively 167.56~659.12ng/m3,87.36~ 362.31ng/m3,78.88~208.40ng/m3,181.65~742.01ng/m3,50.84~315.36ng/m3,42.34~541.45ng/m3, 199.78~628.08ng/m3, 276.82~ 441.27ng/m3;And those of outdoor were respectively168.02~403.01ng/m3,82.98~208.40ng/m3,73.46~208.47ng/m3,189.75~487.06ng/m3,64.26~193.26ng/m3,45.96~401.12ng/m3,182.17~807.95ng/m3,349.62~530.27ng/m3.The mass concentration of each element studied in this area were higher compared with results in other researches. All elements made up a significant proportion in fine particulate matter, which was harmful to the environment and human health. The outdoor particles’ results of principal component analysis showed that the outdoor PM10 mainly origined from coal, vehicle exhaust and metallurgical machinery processing activities.3.The students’ personal exposure levels of fine particulate matter during school time revealed that the students’ comprehensive exposure and comprehensive potential dose increased gradually along with the rise of grade, and that of the sixth grade students were the highest,respectively1674.79μg?h/m3,1261.06 ug.The gaps of grade1,2 and 3 students’ average exposure were small, the levels were slightly higher than that of grade 4 and grade 5 students.The gaps of grade 4, 5 and 6 students’ average potential dosewere not so great, the levels were slightly higher than that of the students from grade one to three.4.The order for the element averge daily dose of students through breathe was Pb﹥Cu﹥Cr﹥Cd﹥Co﹥Ni,respectively 5.62×10-5mg/(kg?d),5.24×10-5mg/(kg?d),1.22×10-5mg/(kg?d),6.97×10-6mg/(kg?d),6.92×10-6mg/(kg?d),4.33×10-6mg/(kg?d).Haz ard quotients of non-cacer trace elements Pb and Cu, were less than 1,which meant less risk in the theory.However,the incremental lifelong cancer risks of the four cancer-risk trace elements(ILCR) were between 10-6~ 10-4,which meant there exgisted potential risk, especially the Cr, Co and Cd elements should be paid more attention. |
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