Sediment Toxicity Testing

Simpson, Stuart L.; Campana, Olivia; Ho, Kay T.

doi:10.1016/b978-0-12-803371-5.00007-2

Cited by 11 publications

(6 citation statements)

References 145 publications

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“…PFOS level was surprisingly much lower in benthic biota than in most pelagic biota, which was contradicted to literature findings that benthic biota tended to contain higher levels of PFAAs . This might be because benthic biota fed on all kinds of small particles near the sediment layer and was at a lower trophic level than pelagic fish, which reduced the magnitude of biomagnification. Also, the high standard deviations showed large variance in measurements and a more comprehensive study was needed to reach a certain conclusion.”…”

Section: Results and Learning Outcomescontrasting

confidence: 77%

Measuring Perfluoroalkyl Acid Contamination at a Local Hot Spot: An Authentic Field-Based Laboratory Experience in a Senior Analytical Environmental Chemistry Course

et al. 2022

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Fieldwork is a meaningful and authentic learning experience that is rarely included in undergraduate chemistry courses. In this laboratory, we visited a hot spot of perfluoroalkyl acid (PFAA) contamination identified in 2012, in Binbrook, Ontario, Canada, a 1 h drive from the University of Toronto. The persistence and unique environmental partitioning properties of PFAAs at these levels provide an excellent opportunity for students to apply a variety of practical environmental sampling techniques in a real-world scenario. We have taken our cross-listed senior undergraduate and graduate class, CHM410-1410 Analytical Environmental Chemistry, to the site and a nearby background site to collect water, sediment, invertebrates, and fish every October since 2016. Students use matrixspecific extractions and analysis by liquid chromatography−tandem mass spectrometry to quantify seven PFAAs. A major goal of this experiment is to guide students through the process of effective data visualization for the identification and communication of trends and relationships between analytes and their prevalence across environmental samples. This process is facilitated by a report outline where students receive significant feedback prior to writing their final lab report. This laboratory is an authentic learning experience that involves students in all aspects of the investigation from sample collection to extraction, data analysis, interpretation, and communication of results. The field component is also a powerful cohort-building exercise with tangible effects on subsequent peer-to-peer interactions. Given the ubiquitous contamination of PFAAs in the environment, this field-based laboratory experiment could be applied at other institutions.

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Section: Results and Learning Outcomescontrasting

confidence: 77%

Measuring Perfluoroalkyl Acid Contamination at a Local Hot Spot: An Authentic Field-Based Laboratory Experience in a Senior Analytical Environmental Chemistry Course

et al. 2022

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“…Sediment toxicity tests are widely accepted tools to assess the chemical pollution of environmental sediment samples and to measure the toxicity of chemicals added to natural or artificial sediments . Both endo- and epibenthic test organisms like copepods, amphipods, bivalves, and polychaetes are used for toxicity assessments, most requiring a manual or (semi)automated water exchange system to supply oxygen and to remove toxic byproducts for a typical test duration of 10–28 days. However, it has been observed that differences between test setups and protocols can lead to substantial alterations in chemical bioavailability, − emphasizing the need for methods to quantify and understand exposure for better interpretation of laboratory toxicity and extrapolation to field exposure conditions.…”

Section: Introductionmentioning

confidence: 99%

Mind the Exposure Gaps—Modeling Chemical Transport in Sediment Toxicity Tests

Fischer

Hiki

Soetaert

et al. 2021

Environ. Sci. Technol.

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Chemical exposure in flow-through sediment toxicity tests can vary in time, between pore and overlying water, and amid free and bound states, complicating the link between toxicity and observable concentrations such as free pore (C free,pore), free overlying (C free,over), or the corresponding dissolved concentrations (C diss, free + bound to dissolved organic carbon, DOC). We introduce a numerical model that describes the desorption from sediments to pore water, diffusion through pores and the sediment–water boundary, DOC-mediated transport, and mixing in and outflow from overlying water. The model explained both the experimentally measured gap between C free,over and C free,pore and the continuous decrease in overlying C diss. Spatially resolved modeling suggested a steep concentration gradient present in the upper millimeter of the sediment due to slow chemical diffusion in sediment pores and fast outflux from the overlying water. In contrast to continuous decrease in overlying C diss expected for any chemical, C free,over of highly hydrophobic chemicals was kept relatively constant following desorption from DOC, a mechanism comparable to passive dosing. Our mechanistic analyses emphasize that exposure will depend on the chemical’s hydrophobicity, the test organism habitat and uptake of bound chemicals, and the properties of sediment components, including DOC. The model can help to re-evaluate existing toxicity data, optimize experimental setups, and extrapolate laboratory toxicity data to field exposure.

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“…The conventional approaches to directly assess metal bioavailability in sediments have relied heavily upon long-term bioaccumulation , and toxicity tests. ,, The former approach intends to quantify the bioavailability by comparing the tissue metal concentrations before and after the sediment exposure, while the latter approach indirectly derives the bioavailability relying on the metal exposure–toxicity relationship. Both approaches require long-term contaminant exposure to accumulate detectable and reliable changes in metal concentrations or for the toxic effects to manifest and are also challenged by the ability to replicate field conditions. , …”

Section: Introductionmentioning

confidence: 99%

Isotopically Modified Bioassay Bridges the Bioavailability and Toxicity Risk Assessment of Metals in Bedded Sediments

Simpson

et al. 2022

Environ. Sci. Technol.

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The application of bioavailability-based risk assessment for the management of contaminated sediments requires new techniques to rapidly and accurately determine metal bioavailability. Here, we designed a multimetal isotopically modified bioassay to directly measure the bioavailability of different metals by tracing the change in their isotopic composition within organisms following sediment exposure. With a 24 h sediment exposure, the bioassay sensed significant bioavailability of nickel and lead within the sediment and determined that cadmium and copper exhibited low bioavailable concentrations and risk profiles. We further tested whether the metal bioavailability sensed by this new bioassay would predict the toxicity risk of metals by examining the relationship between metal bioavailability and metal toxicity to chironomid larvae emergence. A strong dose–toxicity relationship between nickel bioavailability (nickel assimilation rate) and toxicity (22 days emergence ratio) indicated exposure to bioavailable nickel in the sediment induced toxic effects to the chironomids. Overall, our study demonstrated that the isotopically modified bioassay successfully determined metal bioavailability in sediments within a relatively short period of exposure. Because of its speed of measurement, it may be used at the initial screening stage to rapidly diagnose the bioavailable contamination status of a site.

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Sediment Toxicity Testing

Cited by 11 publications

References 145 publications

Measuring Perfluoroalkyl Acid Contamination at a Local Hot Spot: An Authentic Field-Based Laboratory Experience in a Senior Analytical Environmental Chemistry Course

Measuring Perfluoroalkyl Acid Contamination at a Local Hot Spot: An Authentic Field-Based Laboratory Experience in a Senior Analytical Environmental Chemistry Course

Mind the Exposure Gaps—Modeling Chemical Transport in Sediment Toxicity Tests

Isotopically Modified Bioassay Bridges the Bioavailability and Toxicity Risk Assessment of Metals in Bedded Sediments

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