Acute toxicity of piggery effluent and veterinary pharmaceutical cocktail on freshwater organisms

Abstract

Intensive livestock farming has increased the use of veterinary pharmaceuticals in many developing countries, and this is considered a signifcant concern to the freshwater ecosystem. However, the information on the potential acute toxicity of piggery efuent waste and the veterinary pharmaceutical efuent discharged into the aquatic environment is limited. This study assessed the adverse efect of a piggery efuent and the cocktail mixtures of highand low-level doses of three frequently occurring veterinary pharmaceuticals (tetracycline (TETR), ivermectin (IVER), and salicylic acid (SALA)) on freshwater organisms using three representative freshwater biotests organisms: Pseudokirchneriella subcapitata (P. subcapitata), Daphnia magna (D. magna), and Tetrahymena thermophila (T. thermophila). The freshwater organism test results showed that the 24-h and 48-h EC50 algal toxicity to P. subcapitata exposed to 10% unfltered piggery efuent were 25.6 and 49.3% respectively while the 24-h LC50 value to Cladocera, D. magna exposed to unfltered piggery efuent was 23.2 (17.7–30.4)%. The 24-h EC50 protozoan toxicity to T. thermophila exposed to 1% HLD veterinary pharmaceuticals was 0.014 μg/L. Thus, the study established the diferent sensitivities of freshwater organisms to various percentage levels of piggery efuent and high- and low-level doses of veterinary pharmaceutical. The piggery efuent and the pharmaceutical cocktail mixtures have potential toxicological efects on the freshwater ecosystem.