Toxicity of green energy by-products beryllium and tungsten to temperate freshwater species from a Global Biodiversity Hotspot

Abstract

The globally distributed precious metals beryllium and tungsten have recently become elements of interest for environmental regulators due to their presence in mine tailings and their potential to migrate to the broader environment. The chronic toxicity of these elements to freshwater species is poorly understood, which is of particular concern in the Southwest Australia ecoregion, an area classified as a Global Biodiversity Hotspot, given the significant existing and proposed mining activities in the region. Here, the chronic toxicity of beryllium and tungsten was assessed using the recently developed Southwest Australian Toxicity Test Suite, comprising eight species local to the region. Beryllium was generally more toxic to local species than tungsten, with sensitivity based on the no (significant) effect concentrations (N(S)EC) ranging from 667–3,300 µg/L (beryllium) and 2,000–4,770 µg/L (tungsten) in moderately hard water. Species sensitivity (N(S)EC) to beryllium from most to least sensitive was cladoceran, Ceriodaphnia dubia > alga, Chlamydomonas oviformis > green hydroid, Hydra viridissima > alga, Scenedesmus sp. > alga, Chlorella sp. > cladoceran, Simocephalus exspinosus > alga, Tetradesmus obliquus > gastropod, Glyptophysa georgiana. The order of sensitivity for tungsten was different: Hydra viridissima > Chlorella sp. > Scenedesmus sp. > Tetradesmus obliquus > Glyptophysa georgiana > Ceriodaphnia dubia > Simocephalus exspinosus > Chlamydomonas oviformis. Median effect concentrations (EC50s) and 10% effect concentrations (EC10s) are also presented. This article provides chronic toxicity datasets for beryllium and tungsten to inform environmental risk assessment in the region and contribute to the knowledgebase of these globally significant toxicants.