Abstract: Background, aim, and scope Heavy metal lead in urban street dust is an important potential source of blood lead. The primary and high school students are susceptible to lead pollution, so, the heavy metal lead content in indoor and outdoor dust of primary and high schools is very important to students' health. Materials and methods The indoor and outdoor dust in the urban and rural areas of Baoji City, including the urban, suburban towns, rural and lead-zinc smelters, was collected. The Pb content of the dust was analyzed by ICP-MS after microwave digestion. Based on the lead content, the ecological hazards was assessed using the potential ecological hazard index and the accumulation of lead methods. Results The lead content was 627.18mg/kg and 679.39 mg/kg in indoor and outdoor school of the city centre area, respectively. The average content of lead was 593.61mg/kg and 635.46 mg/kg in indoor and outdoor school of the urban area, respectively. The lead content in the rural area was lower than city centre area and the urban area, the results were 217.33mg/kg and 268.57 mg/kg. The lead content in lead and zinc smelters area was highest than other area, the results were reached 2717.62mg/kg and 3296.27mg/kg. Discussion Due to the rapid development of modern industry, the main reason that the Lead content in indoor and outdoor school dust of Baoji city was higher than domestic and foreign cities was the industrial production emissions, especially lead and zinc smelter emissions. Coupled with the special characteristics topography of Baoji city. The pollution degree of the dust was increased. Conclusions The lead content of heavy metals in indoor and outdoor school dust of Baoji City was higher than that in domestic and foreign cities. Excluded rural area, the lead content of other area was more than 30 times of Shaanxi surface soil values. Pb pollution level and potential ecological risk in Baoji City had reached a serious level base on two kinds of evaluation methods. Recommendations and perspectives The results are expected to provide important scientific basis for regional environmental protection, environmental pollution controlling, management and health protection of Baoji city.
Keywords: Exposure; lead; indoor and outdoor; dust; primary and high schools