Arsenic acute toxicity assessment on select freshwater organism species in Malaysia

Abstract

Recently, arsenic has contaminated the aquatic ecosystem, raising government and public environmental concern. In this study, four freshwater organisms were used to evaluate arsenic toxicity levels. Two types of fish, namely Poecilia reticulata (guppy) (Poeciliidae) and Rasbora Sumatrana (Cyprinidae), an aquatic worm species Tubifex tubifex (Oligochaeta) and diptera midge larvae Chironomus javanus (Chironomidae) were exposed for a 4-day (96 h) period in laboratory conditions to a range of arsenic (As) concentrations. Mortality was assessed and median lethal times (LT50) and concentrations (LC50) were calculated. The objective of this study is to determine the acute toxicity of arsenic concentration on Poecilia reticula, Rasbora sumatrana, Tubifex tubifex and Chironomus javanus. Results showed that LT50 and LC50 increase with the decrease in mean exposure concentrations and times. Results indicated that Tubifex tubifex was most sensitive to arsenic toxicity compared to other organisms used in this study in this order; Tubifex tubifex > Chironomus javanus > Rasbora sumatrana > Poecilia reticulata.

Keywords

• acute
• arsenic
• LC₅₀
• LT₅₀
• toxicity