210Pb and Major Ion Concentrations in Aerosols Collected in Qingdao, a Seaside Area of China

This study aimed at understanding the atmospheric concentrations of 210Pb and major ions in aerosols in Qingdao, China, including their seasonal variations and relationships with weather data and to identify the sources of atmospheric sulfur as a part of the Japan-China joint project, “Aeolian Dust Experiment on Climate Impact (ADEC)”. The sampling period was from beginning of May 2001 to beginning of March 2002; and a high air-volume sampler was used with a polyflon filter. Atmospheric concentrations of 210Pb ranged from 0.15±0.03 to 6.63±0.26 mBq m-3 with the mean (±S.D) of 0.93±0.21 mBq m-3 and they showed a clearly seasonal variation with high values in winter to spring and low values in summer to autumn, the lowest values were observed during the rainiest period. Total suspended particles (TSP) ranged from 27.17 to 289.43 µg m-3 with an average of 123.99 µg m-3 which exceeded the World Health Organization (WHO) guideline level for maximum annual exposure of 10 and 20 µg m-3 for PM2.5 and PM10 respectively. The concentrations of Cl-, NO3-, SO42- and NH4+ were high in winter and low in autumn. Mg2+ and Ca2+ concentrations did not show any seasonal variation. Ca2+ shown a strong correlation with TSP (r = 0.81, p<0.01) this revealed that soil particles were mainly the source of TSP. The strong correlation found (r = 0.76, p<0.01) between SO42- and 210Pb shown that they were originated mostly from anthropogenic activities the same conclusion was deducted based on the δ34S sulfate measurement results.