Abstract:
The concentrations of heavy metals in dust samples collected from 101 primary schools and kindergartens of Xi′an city were determined using X-Ray fluorescence spectrometry and their health risk to children was assessed using US EPA health risk assessment method. The results show that the concentrations of Co, Cr, Cu, Pb and Zn in all dust samples are higher than the corresponding background values of Shaanxi soil, while the contents of As, Mn, Ni and V in the most of dust samples are close to or slightly higher than their background values of Shaanxi soil.The health risk assessment results of heavy metals in dust show that the non-carcinogenic risk of heavy metals in dust to children is in an order of Pb>Cr>As>Mn>V>Co>Cu>Ni>Zn, and the carcinogenic risk of heavy metals to children is in an order of Cr>Co>As>Ni. Heavy metals in dust are mainly ingested by human bodies through hand-mouth ingestion, and then through skin absorption and breath suction. The risk of heavy metals in dust from primary school and kindergarten of Xi′an city is relatively low, and there is no obvious hazard to children′ health.
