Toxic effects of pentachlorophenol on Lemna polyrhiza

This paper reports the toxic effects of pentachlorophenol (PCP) on duckweed, Lemna polyrhiza. The 8-day IC 50 of PCP to L. polyrhiza was 8.08 mg/L. At 0.2 and 0.5 mg/L, PCP inhibited L. polyrhiza chloroplast activity. At low PCP exposures, chloroplast activity was more sensitive than chlorophyll content of L. polyrhiza. At 0.2 and 0.5 mg/L, PCP stimulated L. polyrhiza nitrate reductase activity. At 0.2 and 0.5 mg/L PCP, duckweed peroxidase activity was 78.3% and 91.0% of the control test, respectively. The bioaccumulation factors (BCFs) of PCP in L. polyrhiza were 79 and 62 at 0.2 and 0.5 mg/L PCP, respectively. This is the first study of the effect of PCP on peroxidase activity, nitrate reductase activity, and chloroplast activity of L. polyrhiza. The BCFs of PCP in L. polyrhiza are also for reported the first time.