Concentrations, sources and health risk assessments of heavy metals in ground surface dust from urban bus terminals of Fuzhou city

Heavy metals in urban ground surface dust are one of the most serious threats affecting human health and urban environments. Concentrations, sources and health risk assessments of heavy metals in ground surface dust from bus terminals in Fuzhou City were studied to evaluate their pollution levels. The results showed that concentrations of Cr, Cu, Zn and Cd in ground surface dust were 2.74, 4.21, 4.01 and 4.68 times higher than those in the urban soil of Fuzhou City. Co, Ni and Mn in dust came from urban soils; Cd, Pb and Cu were possibly related to transportation process; Cr was mainly associated with urban soil and transportation process; Zn originated from compound pollutant sources including transportation process, urban domestic pollution and industrial activities. The exposure dose and non-cancer risk of heavy metals through exposure decreased as: ingestion>dermal absorption>inhalation. The non-cancer risk for children was higher than for adults. Meanwhile, the cancer risk of heavy metals declined in the order of Cd>Ni>Cr. Heavy metals in ground surface dust from urban bus terminals are mainly affected by transportation process.