The study of fine and coarse particles, and metallic elements for the daytime and night-time in a suburban area of central Taiwan, Taichung

Daily average concentrations of fine and coarse particulates, and TSP sampl es have been measured simultaneously at daytime and night-time periods by u sing Universal and PS-1 sampler in a suburban area of central Taiwan from J une to August 1998, The samples were analyzed by atomic absorption spectrom etry to determine the fine and coarse particulate concentrations of metalli c elements (Ca, Fe, Mn, Pb, Cu, Zn and Cr). The concentration of PM2.5 and TSP showed a decreased trend for the daytime period. The fine particle conc entrations were about two times as that of coarse particulate concentration s. The averaged fine particulate concentrations at daytime are higher than at night-time. Ca and Fe were mostly in the coarse particulate mode. The co rrelation coefficients were 0.63 and 0.69 for elements Ca and Fe in the coa rse particle mode for day and night periods, Pb showed a similar distributi on ratio with Mn for the fine to coarse particle ratios at both day and nig ht period, Pb and Mn are highly correlated for the day (R = 0.78) and night period (R = 0.61) at particle size <2.5 mu m. Cu and Zn were mainly in fin e particles at both day and night period, Fe and Ca consist of the major pa rts of all the elements. Elemental Mn is the lowest among the rest of the h eavy metals. (C) 2000 Elsevier Science Ltd. All rights reserved.