A 1-year field sampling of PM(10) was performed at a town that usually has the worst air quality in Taiwan to examine if PM(10) is a good indicator for pollutant-induced cytotoxicity. The average PM(10) concentration in summer was the lowest, while the other three seasons did not show statistical difference in their PM(10) means. The pollutant-induced cytotoxicity presented as the cumene-hydroperoxide equivalent concentration (CEC) was found to positively correlate with PM(10) concentrations and this study yielded a yearly average of the seasonal CEC 12.+/-8.54 microM with the magnitudes in sequence for the four seasons as: fall>winter>spring>summer. Positive relationship was also found between seasonal PM(10) and their corresponding CECs. The exponential regression model obtained from this study shows: CEC=3.305 exp(0.0118 PM(10)) (R(2)=0.634). The CEC correlates more significantly with NO(3)(-), SO(4)(2-), NH(4)(+) and Cl(-) (secondary aerosol species) than with the Na(+), K(+), Ca(2+) and Mg(2+) (crust-related species) in PM(10). However, the best multivariable model obtained from this study to relate CEC with the concentrations of PM(10)-bearing water-soluble species shows: CEC=exp(1.4751+0.0470[SO(4)(2-)]+0.0143[NO(3)(-)]) (R(2)=0.550).