Artemia salina as a bioindicator for heavy metals

Abstract

Within our country, water toxicity assays are predominantly carried out using physicochemical analyses. While these parameters are accepted by current local regulations, additional regulations are being implemented around the globe, one of which is known as 'biomonitoring.' This involves evaluating toxicity in living organisms to study the potential effects of samples on them. This includes considering the possibility of synergistic effects of compounds present in the water, although the absence of synergy or even the presence of antagonistic effects can also occur. Toxicity resulting from environmental contamination cannot solely be explained through the analysis of individual parameters. Thus, the only way to evaluate its toxic potency is through the application of toxicity assays or tests using standardized living organisms for this purpose. In this study, Artemia salina, a species of crustacean found in brackish waters, was used. The mobility and viability of the Artemia were evaluated using an infrared microbeam motion counter and microscopic counting, respectively. The Artemia were incubated with different metals for for 0, 1, and 24 hours. Effects produced by Cu²⁺, Zn²⁺, Pb²⁺ at concentrations ranging from 0 to 300 mg/L were examined. Additionally, morphologies were analyzed only at 24 hours of exposure to each metal to assess macroscopic toxic effects. No significant changes were recorded until 24 hours, a concentration-dependent increase in mortality was observed for all tested metals. From these data, the lethal concentration 50 (LC50) was determined for the different metals, with Pb⁺² being the most toxic at an LC50 of 13.40 mg/L, followed by Zn²⁺ (45.02 mg/L) and Cu²⁺ (149.63 mg/L). A decrease in movement was observed at 24 hours across all tested concentrations. Finally, morphological changes were observed primarily in the gastrointestinal tract, potentially resulting from bioaccumulation. In conclusion, using Artemia salina as a bioindicator would enable the assessment of compound toxicity in solution over a short period, in a simple and economically accessible manner.