Assessing the Risk of Metals and Their Mixtures in the Antarctic Nearshore Marine Environment with Diffusive Gradients in Thin-Films

Abstract

Robust environmental assessments and contaminant monitoring in Antarctic near-shore marine environments need new techniques to overcome challenges presented by a highly dynamic environment. This study outlines an approach for contaminant monitoring and risk assessment in Antarctic marine conditions using diffusive gradients in thin-films (DGT) coupled to regionally-specific ecotoxicology data and environmental quality standards. This is demonstrated in a field study where DGT samplers were deployed in the near-shore marine environment of East Antarctica around the operational Casey station and the abandoned Wilkes station to measure the time-averaged biologically available fraction of metal contaminants. The incorporation of DGT-labile concentrations to reference toxicity mixture models for three Antarctic organisms predicted low toxic effects (<5% effect to the growth or development of each organism). The comparison of metal concentrations to the Australian and New Zealand default water quality guideline values (WQGVs) showed no marine site exceeding the WQGVs for 95% species protection. However, all sites exceeded the 99% WQGVs due to copper concentrations that are likely of geogenic origin (i.e. not from anthropogenic sources). This study provides evidence supporting the use of the DGT technique to monitor contaminants and assessing their environmental risk in the near-shore marine environment of Antarctica.

The Influence of pH on Zinc Lability and Toxicity to a Tropical Freshwater Microalga

“…In recent years there has been increased research into linking DGT‐labile metal measurements to metal bioavailability to predict metal toxicity to test organisms (Koppel et al, 2019; Philipps et al, 2018). The DGT technique has been shown to be subject to uptake effects with changing pH, with Zhang and Davison (1995) demonstrating that above pH 5 the DGT‐labile cadmium in pH‐adjusted ultrapure water was unaffected by proton competition, with uptake effects from elevated proton concentrations being present only at lower pH (2.3–5).…”

Fungal bioremediation of soil co-contaminated with petroleum hydrocarbons and toxic metals

“…This could provide scientific explanations for fungal responses to multiple contaminants at the molecular level (Aydin et al 2017 ; Wang et al 2017 ). Further, to obtain high-resolution spatial distribution characteristics of toxic metals and reveal interface reaction processes of soil-metals-fungal interactions, new methods such as gradient diffusion film technology (DGT) combined with laser ablation-inductively coupled plasma mass spectrometry could be applied to analyze dynamic changes in toxic metal speciation at soil-microbe interfaces (Challis et al 2018 ; Feng et al 2016 ; Koppel et al 2020 ; Wang et al 2018 ). Such approaches will further clarify fungal transformation mechanisms in soil contaminated with petroleum hydrocarbons and toxic metals and may contribute to more effective strategies for fungal bioremediation.…”

Risk assessment of eight metals and their mixtures to aquatic biota in sediments with diffusive gradients in thin films (DGT): a case study in Pearl River intertidal zone

“…Diffusive gradients in thin films (DGT) is a passive sampling technique that has been applied to evaluate labile metal concentrations in waters, soils, and sediments since 1994 [13][14][15][16], and has recently been used to predict the toxicity and bioavailability of metals to benthic organisms [3,17,18]. Yet, the DGT technique has rarely been used for environmental toxicology purposes to determinate the concentrations of an integrated pool of labile metals present in water and in weakened form in waters associated with sediments [3].…”