Lead exposure characteristics and pollution evaluation of indoor and outdoor dust in primary school campuses of Baoji city in northwest China

Lead in dust is an important potential source of human exposure to lead. The indoor and outdoor dust in the urban and rural areas of Baoji City, a typical industrial city of northwest China, 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. The results reveal that the lead content was 627.18 mg/kg and 679.39 mg/kg in indoor and outdoor school of the city center area, respectively. The average content of lead was 593.61 mg/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 center area and the urban area, the results were 217.33 mg/kg and 268.57 mg/kg. The lead content in lead and zinc smelters area was highest than other area, the results were reached 2717.62 mg/kg and 3296.27 mg/kg. Pb pollution level and potential ecological risk in Baoji City had reached a serious level based on two kinds of evaluation methods. The results are expected to provide important scientific basis for regional environmental protection, environmental pollution controlling, management and health protection of Baoji city.