[Effects of Pb2+ and Cd2+ pollution on physiological characteristics of Thuidium cymbifolium]

This paper dealt with the effects of Pb2+, Cd2+ and their combined pollution on the contents of chlorophyll, potassium and calcium in Thuidium cymbifolium. The results showed that except at 0.1 mg Cd2+.L(-1), the chlorophyll content decreased with increasing Pb2+ and Cd2+ concentrations, which was 18% of the control at 100 mg Cd2+.L(-1), and decreased by 48.6% at 200 mg Pb2+.L(-1). The potassium and calcium contents also decreased with increasing pollutants concentrations, being decreased by 61.1% at 100 mg Cd2+.L(-1). Cd2+ had a stronger toxicity than Pb2+, and the toxicity of their combined pollution was stronger than that of each pollutant. Pb2+ could increase the toxicity of Cd2+.