We propose novel chemometers - passive equilibrium samplers of,
e.g.
, silicone - as an integrative tool for the assessment of hydrophobic organic compounds in multimedia environments. The ...traditional way of assessing levels of organic pollutants across different environmental compartments is to compare the chemical concentration normalized to the major sorptive phase in two or more media. These sorptive phases for hydrophobic organic compounds differ between compartments,
e.g.
, lipids in biota and organic carbon in sediments. Hence, comparability across media can suffer due to differences in sorptive capacities, but also extraction protocols and bioavailability. Chemometers overcome these drawbacks; they are a common, universal and well-defined polymer reference phase for sampling of a large range of nonpolar organic pollutants in different matrices like biota, sediment and water. When bringing the chemometer into direct contact with the sample, the chemicals partition between the sample and the polymer until thermodynamic equilibrium partitioning is established. At equilibrium, the chemical concentrations in the chemometers can be determined and directly compared between media,
e.g.
, between organisms of different trophic levels or inhabiting different areas, between organs within an organism or between biotic and abiotic compartments, amongst others. Chemometers hence allow expressing the data on a common basis, as the equilibrium partitioning concentrations in the polymer, circumventing normalizations. The approach is based on chemical activity rather than total concentrations, and as such, gives a measure of the "effective concentration" of a compound or a mixture. Furthermore, chemical activity is the main driver for partitioning, biouptake and toxicity. As an additional benefit, the extracts of the chemometers only require limited cleanup efforts, avoiding introduction of a bias between chemicals of different persistence, and can be submitted to both chemical analysis and/or bioanalytical profiling.
Chemometers, polymeric passive equilibrium samplers, are promising tools for environmental and human health assessment of a broad range of hydrophobic organic compounds and allow for direct comparison of chemical profiles and levels across media.
We described in 2017 how weathering plastic litter in the marine environment fulfils two of three criteria to impose a planetary boundary threat related to “chemical pollution and the release of ...novel entities”: (1) planetary-scale exposure, which (2) is not readily reversible. Whether marine plastics meet the third criterion, (3) eliciting a disruptive impact on vital earth system processes, was uncertain. Since then, several important discoveries have been made to motivate a re-evaluation. A key issue is if weathering macroplastics, microplastics, nanoplastics, and their leachates have an inherently higher potential to elicit adverse effects than natural particles of the same size. We summarize novel findings related to weathering plastic in the context of the planetary boundary threat criteria that demonstrate (1) increasing exposure, (2) fate processes leading to poorly reversible pollution, and (3) (eco)toxicological hazards and their thresholds. We provide evidence that the third criterion could be fulfilled for weathering plastics in sensitive environments and therefore conclude that weathering plastics pose a planetary boundary threat. We suggest future research priorities to better understand (eco)toxicological hazards modulated by increasing exposure and continuous weathering processes, to better parametrize the planetary boundary threshold for plastic pollution.
Plastics are produced with a staggering array of chemical compounds, with many being known to possess hazardous properties, and others lacking comprehensive hazard data. Furthermore, ...non-intentionally added substances can contaminate plastics at various stages of their lifecycle, resulting in recycled materials containing an unknown number of chemical compounds at unknown concentrations. While some national and regional regulations exist for permissible concentrations of hazardous chemicals in specific plastic products, less than 1 % of plastics chemicals are subject to international regulation 1. There are currently no policies mandating transparent reporting of chemicals throughout the plastics value chain or comprehensive monitoring of chemicals in recycled materials.
The dataset presented here provides the chemical analysis of 28 samples of recycled High-Density Polyethylene (HDPE) pellets obtained from various regions of the Global South, along with a reference sample of virgin HDPE. The analysis comprises both Target and Non-Targeted Screening approaches, employing Liquid Chromatography-High-Resolution Mass Spectrometry (LC-HRMS) and Gas Chromatography-High-Resolution Mass Spectrometry (GC-HRMS). In total, 491 organic compounds were detected and quantified, with an additional 170 compounds tentatively annotated. These compounds span various classes, including pesticides, pharmaceuticals, industrial chemicals, plastic additives.
The results highlight the prevalence of certain chemicals, such as N-ethyl-o-Toluesulfonamide, commonly used in HDPE processing, found in high concentrations. The paper provides a dataset advancing knowledge of the complex chemical composition associated with recycled plastics.
The present study complements work on mixture effects measured with
in vitro
bioassays of passive equilibrium sampling extracts using the silicone polydimethylsiloxane (PDMS) in organs from marine ...mammals with chemical profiling. Blubber, liver, kidney and brain tissues of harbor porpoise (
Phocoena phocoena
), harbor seal (
Phoca vitulina
), ringed seal (
Phoca hispida
) and orca (
Orcinus orca
) from the North and Baltic Seas were investigated. We analyzed 117 chemicals including legacy and emerging contaminants using gas chromatography-high resolution mass spectrometry and quantified 70 of those chemicals in at least one sample. No systematic differences between the organs were found. Only for single compounds a clear distribution pattern was observed. For example, 4,4′-dichlorodiphenyltrichloroethane, enzacamene and etofenprox were mainly detected in blubber, whereas tonalide and the hexachlorocyclohexanes were more often found in liver. Furthermore, we compared the chemical profiling with the bioanalytical results using an iceberg mixture model, evaluating how much of the biological effect could be explained by the analyzed chemicals. The mixture effect predicted from the quantified chemical concentrations explained 0.014-83% of the aryl hydrocarbon receptor activating effect (AhR-CALUX), but less than 0.13% for the activation of the oxidative stress response (AREc32) and peroxisome-proliferator activated receptor (PPARγ). The quantified chemicals also explained between 0.044-45% of the cytotoxic effect measured with the AhR-CALUX. The largest fraction of the observed effect was explained for the orca, which was the individuum with the highest chemical burden. This study underlines that chemical analysis and bioassays are complementary to comprehensively characterize the mixture exposome of marine mammals.
The analysis of mixtures of environmental contaminants from marine mammal organs revealed distinct distribution patterns for single compounds. The combination of chemical analysis and bioassays can comprehensively characterize the mixture exposome.
Dolphins are considered sentinel species in the marine environment. The Strait of Gibraltar is the only passage between the Mediterranean Sea and the Atlantic Ocean, being the transitional region ...which connects these two basins and one of the most important routes of cetacean migration worldwide. In this work, eight trace elements (TE) were studied in 45 samples of liver, kidney and muscle, from 15 specimens stranded in this study area. The preliminary results show, among others, the patterns of distribution of the TE in the target organs studied, the influence of sex, length and developmental stage in these TE concentrations and the Se/Hg ratio. Subsequently, the results of TE concentrations in liver have being compared to previous data on S. coeruleoalba from the westernmost Mediterranean Sea and the nearest Atlantic Ocean. For some elements (e.g. for As), concentrations are similar to those obtained from Atlantic samples, despite in other cases (e.g. for Cd) results are lined up with those observed in Mediterranean studies. In addition, in the case of some TE (e.g. Se and Zn) the results are in the middle of those reported for both basins, reinforcing the idea of the Strait of Gibraltar being a transitional zone. Present study is the first research regarding this issue in this outstanding region, aiming to give insights of how this matchless area can help to link TE concentrations observed in these Atlantic and Mediterranean threatened species.
•Stranded dolphins are good bioindicators showing great potential as monitoring tools.•Trace elements were first measured in stranded dolphins in the Strait of Gibraltar.•Trace elements are compared among target organs and correlated to biological parameters.•First report of Se/Hg ratio in cetaceans from this relevant transitional region.•This region can be considered a transitional area between Mediterranean and Atlantic basins.
Passive equilibrium sampling using polymer samplers in lean tissue is one of the current challenges in assessing bioaccumulation and biomagnification due to the long time needed to reach equilibrium. ...Despite recent progress achieved by rolling pieces of intact fish fillet with sheets of silicone, there is still a need for a passive sampling method for homogenates that achieves equilibrium before tissue decay starts. In this work, a new approach for relocation of silicone passive samplers in homogenates of lean fish was established for three homogenates with lipid contents varying from 1.2% to 6.1%. Results showed that for 20 model hydrophobic organic compounds with log KOW between 3.9 and 7.8, equilibrium between the silicone and the tissue was achieved in less than 3 days at 4 °C. The concentrations in lipids obtained using passive equilibrium sampling and those from traditional total solvent extraction agreed well, within a factor of 1.3. This new procedure extends the use of passive samplers to homogenised fish tissues of low lipid content, which is highly relevant for environmental studies focused on bioaccumulation of contaminants.
Display omitted
•A new approach for relocation of passive samplers in homogenised tissues was successfully established.•This procedure opens up for the use of passive samplers in fish homogenates of low lipid content.•Organic compounds with log KOW between 3.9 and 7.8 reached equilibrium in less than 3 days.
The present study complements work on mixture effects measured with
bioassays of passive equilibrium sampling extracts using the silicone polydimethylsiloxane (PDMS) in organs from marine mammals ...with chemical profiling. Blubber, liver, kidney and brain tissues of harbor porpoise (
), harbor seal (
), ringed seal (
) and orca (
) from the North and Baltic Seas were investigated. We analyzed 117 chemicals including legacy and emerging contaminants using gas chromatography-high resolution mass spectrometry and quantified 70 of those chemicals in at least one sample. No systematic differences between the organs were found. Only for single compounds a clear distribution pattern was observed. For example, 4,4'-dichlorodiphenyltrichloroethane, enzacamene and etofenprox were mainly detected in blubber, whereas tonalide and the hexachlorocyclohexanes were more often found in liver. Furthermore, we compared the chemical profiling with the bioanalytical results using an iceberg mixture model, evaluating how much of the biological effect could be explained by the analyzed chemicals. The mixture effect predicted from the quantified chemical concentrations explained 0.014-83% of the aryl hydrocarbon receptor activating effect (AhR-CALUX), but less than 0.13% for the activation of the oxidative stress response (AREc32) and peroxisome-proliferator activated receptor (PPARγ). The quantified chemicals also explained between 0.044-45% of the cytotoxic effect measured with the AhR-CALUX. The largest fraction of the observed effect was explained for the orca, which was the individuum with the highest chemical burden. This study underlines that chemical analysis and bioassays are complementary to comprehensively characterize the mixture exposome of marine mammals.
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