Acute Toxicity of Magnetite Nanoparticles Coated With Oleic Acid In The Amphipod Hyalella curvispina

ESPERT NURIA; MORELL MALENA; MARDIROSIAN MARIANA; JORGELINA VILLANOVA

Montevideo

Congreso; SETAC Latín América 15th biennial meeting; 2023

The main productive activities in North Patagonia are oil and gas exploitation and fruit culture. Suchactivities may generate pollutants that can reach natural and artificial watercourses, affecting aquatic life.Due to the high quality of regional water resources, there is an environmental preservation requirement fromdifferent social actors. In this context, the presence of organic contaminants on aquatic environmentsrequire effective solutions and there is a worldwide growing necessity of techniques that minimize theirconcentration. Nowadays, the development of environmental remediation technologies using nanomaterialshas emerged as an interesting alternative. However, prior to their application, it is necessary to carry out aninitial toxicity evaluation of these materials. Our aim was to evaluate the acute toxicity of magnetitenanoparticles coated with oleic acid (NPOA), developed and synthesized by our group for the remediationof hydrocarbons-contaminated water. This study analyzed NPOA acute effects in adult individuals of thenative amphipod Hyalella curvispina. Individuals were collected from a reference site in Mari Menuco Lake,Neuquén, Argentina. The amphipods were maintained and raised under laboratory conditions. Groups of 10adults were exposed to a range of NPOA concentrations in 250 ml of filtered and dechlorinated water,during 96 hours at constant temperature of 23 ± 1°C and 16:8 h (L:D) photoperiod. The concentrationstested were 1, 5, 10, 25, 50, and 100 mg/l. Mortality and behavioral alterations were employed as endpointsto determine toxicological parameters. Significant differences were observed at 96 hs only between controland 5 mg/l with regards to mortality. The analysis of behavioral alterations show significant differencesbetween control and all the NPOA concentrations tested, reaching up to 58% of exposed individuals.NPOA-exposed individuals showed alterations such as changes in reaction speed, locomotor behavior andincrease in ventilation frequency. Our results suggest that the lethal effects of the NPOA could varyaccording to their aggregation state in the medium. NPOA aggregation starts at 10 mg/l, and is more visibleas concentration increases. Hence, mortality does not show a linear relationship with concentration, whilebehavioral alterations do. Thus, behavioral alterations become more relevant in amphipod health statusthan direct lethal effects driven by NPOA exposure.