Characteristics of re-suspended road dust and its impact on the atmospheric environment in Beijing

A sampling campaign of re-suspended road dust samples from 53 sites that could cover basically the entire Beijing, soil samples from the source regions of dust storm in August 2003, and aerosol samples from three representative sites in Beijing from December 2001 to September 2003, was carried out to investigate the characteristics of re-suspended road dust and its impact on the atmospheric environment. Ca, S, Cu, Zn, Ni, Pb, and Cd were far higher than its crustal abundances and Ca2+, SO42−, Cl−, K+, Na+, NO3− were major ions in re-suspended road dust. Al, Ti, Sc, Co, and Mg in re-suspended road dust were mainly originated from crustal source, while Cu, Zn, Ni, and Pb were mainly derived from traffic emissions and coal burning, and Fe, Mn, and Cd were mainly from industrial emissions, coal combustion and oil burning. Ca2+ and SO42− mainly came from construction activities, construction materials and secondary gas-particle conversions, Cl− and Na+ were derived from industrial wastewater disposal and chemical industrial emissions, and NO3− and K+ were from vehicle emissions, photochemical reactions of NOX, biomass and vegetable burning. The contribution of mineral aerosol from inside Beijing to the total mineral aerosols was 30% in spring of 2002, 70% in summer of 2002, 80% in autumn of 2003, 20% in PM10 and 50% in PM2.5, in winter of 2002. The pollution levels of the major pollution species, Ca, S, Cu, Zn, Ni, Pb, Fe, Mn, and Cd in re-suspended road dust reached 76%, 87%, 75%, 80%, 82%, 90%, 45%, 51%, and 94%, respectively. Re-suspended road dust from the traffic and construction activities was one of the major sources of pollution aerosols in Beijing.