Acute waterborne and chronic sediment toxicity of silver and titanium dioxide nanomaterials towards the oligochaete, Lumbriculus variegatus

Abstract The use of silver (Ag) and titanium dioxide (TiO2) nanomaterials (NMs) in industrial processes and consumer products has experienced considerable growth since the late 20th century. Throughout their lifecycle, both Ag NM and TiO2NM are released into the environment, with benthic systems anticipated to be the final sink. Their potential toxicity towards benthic species is therefore of major concern. This study investigated the toxicity of silver (Ag; NM-300 K) and titanium dioxide (TiO2; NM-104) NMs to the freshwater oligochaete, Lumbriculus variegatus in acute (0–96-h) waterborne and chronic (28-d) sediment studies. Toxicity was investigated via assessment of mortality, behaviour, and antioxidant enzyme activity. The 96-h LC50 for Ag NMs in water was 0.51 mg/L (95% CI, 0.45–0.56), with L. variegatus displaying inhibited predation-avoidance behaviour compared to controls (6.66 ± 10%) successful response at 24-h), as well as significant increases (p