Heavy Metals and Metalloid Effects on Cytogenetics in Frogs (Sylvirana nigrovittata) around the Sepon Gold-Copper Mine, Lao PDR

Abstract

Abstract The objectives of the present study were to determine the concentrations of heavy metals and metalloids in frogs (Sylvirana nigrovittata) and to assess chromosome aberrations (CAs) in frogs collected from the Nam Kok River near the Sepon gold-copper mine, Lao PDR, as compared with those from a reference site. The results showed that the concentrations of As, Cd, Cr, and Mn in the frog muscle samples exceeded the standard values, and the accumulation of heavy metals in the frogs from the two sampling sites was significantly different (P <0.05), particularly Ba, Cd, Cr, Cu, Fe, Mn and Ni. Chromosome assessment of S. nigrovittata from the study site revealed 13 types of CAs, and the highest total number of CAs was isochromatid gap with a percentage of 31.80%. Furthermore, the total number of CAs, cell number with CAs and percentage of CAs in the frogs from both sites were significantly different (P <0.05). The results of this study suggest that heavy metal and metalloid from the Sepon gold-copper mine area negatively affected S. nigrovittata in terms of chromosomal defects. Keywords: Aberration, Abnormality, Amphibian, Animal, Toxicant