Levels of organochlorine pesticides in Amazon turtle (Podocnemis unifilis) in the Xingu River, Brazil

Abstract

Due to the toxicity and high environmental persistence of organochlorine pesticides in aquatic organisms, turtles have been studied as environment biomonitors. These animals are important sources of protein for the riverside and indigenous peoples of the Brazilian amazon. In the present study, organochlorine pesticide contamination was investigated in Podocnemis unifilis. Liver, muscle and fatty tissue samples were removed from 50 specimens collected from five sampling points located in the Xingu River basin. Fourteen organochlorine pesticides were analysed via gas chromatography with an electron capture detector (CG-ECD). Eight organochlorine pesticides were detected with average concentrations of ∑DDT, ∑Endossulfan and ∑HCH which were 26.17 ± 26.35, 14.38 ± 23.77 and 1.39 ± 8.46 ng g⁻¹ in moisture content, respectively. DDT compounds were the most predominant, with a greater concentration of pp′-DDT in the liver and pp′-DDD in the muscle. Significant differences were noted between the types of tissues studied, and the concentration of OCPs varied between sampling sites.

Keywords:

• Contamination
• organochlorine
• pesticide toxicity
• Podocnemis unifilis
• turtle
• Xingu River

Acknowledgements

The authors would like to express their thanks to the Laboratory of Environmental Toxicology (SEMAM) at the Evandro Chagas Institute (IEC), in Ananindeua-PA, for its logistical support during the project and to CAPES [Foundation for the Improvement of Personnel in Higher Education] “Governance, Management and Conflicts and the Handling of Natural Resources in the Amazon Region” for its financial support. Marina T. Pignati is also grateful to the Chico Mendes Institute for Biodiversity Conservation (ICMBio) of Altamira/PA and the Socio-Environmental Institute (ISA) of Altamira/PA for its assistance with field work. This article forms a part of the Doctoral Thesis in Zoology of M.T.P., who would like to thank the Federal University of Pará (UFPA) and the Paraense Emílio Goeldi Museum (MPEG) for its academic and logistical support.