Evaluation of Abnormal Chromosomes in Rice Field Frogs (Fejervarya limnocharis) from Reservoirs Affected by Leachate with Cadmium, Chromium and Lead Contamination

The objectives of this study were to investigate abnormal chromosomes in rice field frogs (Fejervarya limnocharis) in reservoirs affected by leachate compared with a non-affected area. Nine individual of F. limnocharis were collected, and abnormal chromosomes were studied using bone marrow. The level of heavy metal concentrations (cadmium (Cd), chromium (Cr) and lead (Pb)) were measured in water, sediment and F. limnocharis samples. The average concentrations of Cd, Cr and Pb in the water and sediment samples from the municipal landfill and non-affected areas were 0.002±0.000, 0.545±0.876 and 0.021±0.009 and not detected, 0.046±0.032 and 0.009±0.002 mg/l in water as well as 0.472±0.060, 18.652±6.791 and 5.369±0.645 and 0.234±0.019, 4.769±0.142 and 2.176±0.783 mg/kg in sediment, respectively. The municipal landfill values were lower than the permissible limit of the water and soil quality standards, while Cr exceeded the water standard. The average Cd, Cr and Pb concentrations in the F. limnocharis samples from the municipal landfill and non-affected areas were 0.023±0.007, 1.857±0.498 and 0.393±0.128 and 0.007±0.000, 1.349±0.083 and 0.183±0.005 mg/kg, respectively, with the Cd and Cr levels both lower than the standards, but not the Pb levels. The diploid chromosome number of F. limnocharis in both areas was 2n=26, and the percentage of chromosome abnormalities of F. limnocharis in the municipal landfill area were higher than the non-affected area. There were eleven types of chromosome abnormalities, including a single chromatid gap, isochromatid gap, single chromatid break, isochromatid break, centric fragmentation, deletion, fragmentation, translocation, centromere gap, iso-arm fragmentation and single chromatid decompose. The most common chromosome abnormality in the samples from the municipal landfill area was fragmentation. The difference in the percentage of chromosome abnormality in F. limnocharis from both areas was statistically significant (p