Ecotoxicological effects of carbofuran and oxidised multiwalled carbon nanotubes on the freshwater fish Nile tilapia: Nanotubes enhance pesticide ecotoxicity

Author(s)

Campos-Garcia, Janaina ^[1] ; Martinez, Diego Stefani T. ^{[2, 3]} ; Alves, Oswaldo L. ^[2] ; Gervasio Leonardo, Antonio Fernando ^[4] ; Barbieri, Edison ^{[1, 5]}

Affiliation

^[1] Inst Pesca APTA SAA SP, Programa Pos Grad, BR-11900000 Cananeia, SP - Brazil

^[2] Univ Estadual Campinas UNICAMP, Inst Quim, Lab Quim Solido LQES, BR-13081970 Campinas, SP - Brazil

^[3] CNPEM, Lab Nacl Nanotecnol LNNano, BR-13083970 Campinas, SP - Brazil

^[4] Polo Reg Vale Ribeira, BR-11900000 Registro, SP - Brazil

^[5] Inst Pesca APTA SAA SP, BR-11900000 Cananeia, SP - Brazil

• Document type: Journal article
• Source: ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY; v. 111, p. 131-137, JAN 2015.
• Web of Science Citations: 21

Abstract

The interactions of carbon nanotubes with pesticides, such as carbofuran, classical contaminants (e.g., pesticides, polyaromatic hydrocarbons, heavy metals, and dyes) and emerging contaminants, including endocrine disruptors, are critical components of the environmental risks of this important class of carbon-based nanomaterials. In this work, we studied the modulation of acute carbofuran toxicity to the freshwater fish Nile tilapia (Oreochromis niloticus) by nitric acid treated multiwalled carbon nanotubes, termed HNO3-MWCNT. Nitric acid oxidation is a common chemical method employed for the purification, functionalisation and aqueous dispersion of carbon nanotubes. HNO3-MWCNT were not toxic to Nile tilapia at concentrations ranging from 0.1 to 3.0 mg/L for exposure times of up to 96 h. After 24, 48, 72 and 96 h, the LC50 values of carbofuran were 4.0, 3.2, 3.0 and 2.4 mg/mL, respectively. To evaluate the influence of carbofuran-nanotube interactions on ecotoxicity, we exposed the Nile tilapia to different concentrations of carbofuran mixed together with a non-toxic concentration of HNO3-MWCNT (1.0 mg/L). After 24, 48, 72, and 96 h of exposure, the LC50 values of carbofuran plus nanotubes were 3.7, 1.6, 0.7 and 0.5 mg/L, respectively. These results demonstrate that HNO3-MWCNT potentiate the acute toxicity of carbofuran, leading to a more than five-fold increase in the LC50 values. Furthermore, the exposure of Nile tilapia to carbofuran plus nanotubes led to decreases in both oxygen consumption and swimming capacity compared to the control. These findings indicate that carbon nanotubes could act as pesticide carriers affecting fish survival, metabolism and behaviour. (C) 2014 Elsevier Inc. All rights reserved. (AU)