Effects of low doses Trichlorfon exposure on Rana chensinensis tadpoles

Abstract

Trichlorfon is an organophosphate insecticide widely used in aquaculture and agriculture. Little is known about the effects of long-term of low doses trichlorfon exposure on amphibians. In this study, we investigated the effects of low doses trichlorfon on Rana chensinensis tadpoles after exposure to 0.01, 0.1, and 1.0 mg/L trichlorfon for 2 and 4 weeks. Survival, growth, development and mortality were monitored regularly over the course of exposure. The results showed that trichlorfon led to a decrease in tadpole survival. Reductions in growth and disruptions to the development of tadpoles were observed in trichlorfon treatments. Morphological abnormalities of affected tadpoles included axial flexures, skeletal malformations and lateral kinks. Trichlorfon increased the frequency of micronucleus (MN) formation in circulating erythrocytes of tadpoles exposed for 2 weeks to 0.1 and 1.0 mg/L trichlorfon. At all concentrations, an enhanced frequency of MN formation was observed in tadpoles exposed for 4 weeks. Exposure to trichlorfon induced other nuclear abnormalities such as lobed and notched nuclei only in tadpoles exposed to 1.0 mg/L trichlorfon for 4 weeks. In addition, exposure to trichlorfon within the 0.01-1.0 mg/L range increased the genetic damage index in hepatic tissues in all treatments. Apoptosis-associated DNA fragmentation in hepatic tissues occurred in a weak ladder-like pattern. This study presents evidence of low doses trichlorfon effects on amphibians, highlighting the properties of this organophosphate insecticide that jeopardize nontarget species exposed to trichlorfon. K E Y W O R D S development, DNA damage, genotoxicity, tadpoles, trichlorfon

Toxicity, Biodegradation, and Metabolic Fate of Organophosphorus Pesticide Trichlorfon on the Freshwater Algae Chlamydomonas reinhardtii

“…The toxicity of TCF to the crustacean Daphnia magna and the early stages and adults of Danio rerio was 0.29 μg L –1 (LC50 48 h ), 25.4 mg L –1 and 28.8 mg L –1 (LC50 96 h ), respectively . A trichlorfon concentration of 10 μg L –1 is developmentally toxic to Rana chensinensis tadpoles . The detected concentrations of TCF in the Dongjiang River, China were approximately 40–50 ng L –1 , but the risk quotient was above 0.1, which means that there was a risk to aquatic organisms despite the low concentration .…”

“…7 A trichlorfon concentration of 10 μg L −1 is developmentally toxic to Rana chensinensis tadpoles. 8 The detected concentrations of TCF in the Dongjiang River, China were approximately 40−50 ng L −1 , but the risk quotient was above 0.1, which means that there was a risk to aquatic organisms despite the low concentration. 9 Furthermore, TCF has the potential to reach higher concentrations in agriculture and aquaculture areas because of its misuse.…”

Assessment of the Toxicological Effects of Pesticides and Detergent Mixtures on Zebrafish Gills: a Histological Study

“…Pathological findings associated with Temephos exposure are not exclusive to gills but also found in the liver, muscles, and nerve tissue [7,19,[38][39]. Moreover, organophosphates also can induce morphological and biochemical abnormalities in exposed amphibians [40][41].…”

Preparation of a Sensor Based on Biomass Porous Carbon/Covalent-Organic Frame Composites for Pesticide Residues Detection

“…Organophosphorus pesticides (OPs), such as Trichlorfon, have been thoroughly used in agriculture due to their powerful insecticidal ability (Ma et al, 2018 ). However, due to its inhibition of acetylcholinesterase (AChE), the key enzyme of nerve conduction (Baldissera et al, 2019 ), it also poses a major threat to overall health (Soreq and Seidman, 2001 ; Shi et al, 2016b ).…”