Tradescantia bioassays for the determination of genotoxicity of water in the Panlong River, Kunming, People's Republic of China

The Panlong river passes through Kunming City and receives a large quantity of municipal sewage and wastewater from industrial effluent. Along the riv er, 20 sites were selected to collect water samples to assess the genotoxic ity using two Tradescantia assays, the micronucleus (Trad-MCN) and the stam en-hair-mutation (Trad-SHM) assays. The lowest frequencies in the Trad-MCN assay and the Trad-SHM assay are 3.19 MCN/100 tetrads and 1.32 M/1000 stame n hairs, respectively. In the water samples obtained from the Songhua Reser voir, the MCN frequencies and mutation rates are not statistically signific antly different from the data found for the negative control (2.49 MCN/100 tetrads and 0.71 M/1000 stamen hairs). Among the other water samples, 19 in Trad-MCN assay and 17 in Trad-SHM assay show significantly higher genotoxi city than the control. The highest genotoxicity was in samples No. 19 for t he MCN assay (8.73 MCN/100 cells), over three times higher than the negativ e control, and in sample No. 11 for the SHM assay (4.30 M/1000), six times higher than the negative control, and were about the same as for the positi ve control (10.0 mg/l NaN3, 9.28 MCN/100 tetrads and 7.44 SHM/1000 stamen h airs), respectively. The peak frequencies for the Trad-MCN assays were obse rved in the water samples obtained from the sites that were near industrial and municipal wastewater that ran into the river as effluent. In general, the frequency of MCN and SHM mutations increased where the river passed thr ough Kunming. The Trad-MCN assay seemed more sensitive than that of the Tra d-SHM assay in detecting genotoxicity of the river water pollution. (C) 199 9 Elsevier Science B.V. All rights reserved.