Environ Sci Eur. 2025;37(1):19. doi: 10.1186/s12302-025-01054-4. Epub 2025 Jan 29.
ABSTRACT
The EU recently introduced four new hazard classes to the Classification, Labelling and Packaging Regulation (CLP) (EC) 1272/2008. The classes are endocrine disruption for human health (ED HH) and the environment (ED ENV), persistent, bioaccumulative and toxic (PBT) or very persistent and very bioaccumulative (vPvB), and persistent, mobile and toxic (PMT) or very persistent and very mobile (vPvM). This action was a direct consequence of the EU's Chemicals Strategy for Sustainability, which aims at strengthening the protection of human health and the environment, as well as reinforcing the CLP Regulation as the central piece of the chemicals legislation. This study examined the regulatory obligations triggered by these new hazard classes, as well as the existing obligations for endocrine disrupters and PBT/vPvB substances identified in other EU regulations. In addition, we compared the CLP criteria for endocrine disruption and PBT/vPvB to criteria existing in other EU regulations and investigated how these criteria are used in the EU chemicals legislation. We found that the implementation of the new hazard classes under the CLP into existing EU chemicals legislation will require the revision of all regulations that rely on the CLP hazard criteria for risk management. Without revision, the immediate impact of the new hazard classes will only extend to six regulations and the regulatory obligations they contain, all of which apply to substances classified under any of the CLP hazard classes. Meanwhile, substances with endocrine disrupting and PBT/vPvB properties are already being identified and regulated using criteria from regulations other than the CLP. When comparing the criteria for identification of endocrine disrupters and PBT/vPvB substances across the chemicals legislation, we found that the criteria differed between regulations. The findings aim to support the efficient implementation of the new CLP hazard classes and harmonization of criteria across regulations, in line with the Chemicals Strategy for Sustainability.
SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12302-025-01054-4.
PMID:39895675 | PMC:PMC11779689 | DOI:10.1186/s12302-025-01054-4
Toxics. 2024 Dec 25;13(1):6. doi: 10.3390/toxics13010006.
ABSTRACT
Pharmaceuticals and personal care products (PPCPs) are emerging contaminants (ECs), whose presence in the environment is of increasing concern due to their widespread use and possible detrimental effects on wildlife and humans. These chemicals may present multiple hazardous properties such as environmental persistence, toxicity, high mobility, and the potential for bioaccumulation. In this study, extended bibliographic research was conducted to characterize the removal efficiency (RE) of PPCPs in wastewater treatment plants (WWTPs) considering different technologies. Measured values of RE were collected from the literature or calculated for 251 compounds. The molecular structure of the 245 PPCPs were used as the input to generate predictions of multiple properties using several QSAR tools, such as the OECD Toolbox, OPERA, EPI Suite™, and QSAR-ME Profiler. These predictions were compared to regulatory thresholds to identify hazardous chemicals and to screen persistent, mobile and toxic (PMT) or persistent, bioaccumulative and toxic (PBT) substances. Finally, chemicals were prioritized by combining values of RE and QSAR predictions for multiple properties. A total of 16 out of the 245 molecules were prioritized as the most hazardous compounds to the aquatic environment and, among these, six were associated with potential risk due to their exposure concentrations reported in the literature.
PMID:39853006 | PMC:PMC11768813 | DOI:10.3390/toxics13010006
Water Res. 2025 Apr 15;274:123032. doi: 10.1016/j.watres.2024.123032. Epub 2024 Dec 21.
ABSTRACT
The complex sorption mechanisms of carbon adsorbents for the diverse group of persistent, mobile, and potentially toxic contaminants (PMs or PMTs) present significant challenges in understanding and predicting adsorption behavior. While the development of quantitative predictive tools for adsorbent design often relies on extensive training data, there is a notable lack of experimental sorption data for PMs accompanied by detailed sorbent characterization. Rather than focusing on predictive tool development, this study aims to elucidate the underlying mechanisms of sorption by applying data analysis methods to a high-quality dataset. This dataset includes more than 60 isotherms for 22 PM candidates and well-characterized high-surface-area activated carbon (AC) materials. We demonstrate how tools such as distance correlation and clustering can be used effectively to identify the key parameters driving the sorption process. Using these approaches, we found that aromaticity, followed by hydrophobicity, are key sorbate descriptors for sorption, overshadowing steric and charge effects for a given sorbent. Aromatic PMs, although classified as mobile contaminants based on their sorption to soil, are well adsorbed by AC as engineered adsorbent via π-π interactions. Non-aromatic and especially anionic compounds show much greater variability in sorption. The influence of ionic strength and natural organic matter on adsorption was considered. Our approach will help in the analysis of solute-sorption systems and in the development of new adsorbents beyond the specific examples presented here. In order to make the approach accessible, the code is freely available and described on GitHub (https://github.com/Laura-Lotteraner/PM-Sorption), following the FAIR data principles.
PMID:39787835 | DOI:10.1016/j.watres.2024.123032
Environ Sci Technol. 2025 Jan 14;59(1):578-590. doi: 10.1021/acs.est.4c11085. Epub 2024 Dec 16.
ABSTRACT
In silico methods for screening hazardous chemicals are necessary for sound management. Persistent, bioaccumulative, mobile, and toxic (PBMT) chemicals persist in the environment and have high mobility in aquatic environments, posing risks to human and ecological health. However, lack of experimental data for the vast number of chemicals hinders identification of PBMT chemicals. Through an extensive search of measured chemical mobility data, as well as persistent, bioaccumulative, and toxic (PBT) chemical inventories, this study constructed comprehensive data sets on PBMT chemicals. To address the limited volume of the PBMT chemical data set, a transfer learning (TL) framework based on graph attention network (GAT) architecture was developed to construct models for screening PBMT chemicals, designating the PBT chemical inventories as source domains and the PBMT chemical data set as target domains. A weighted loss (LW) function was proposed and proved to mitigate the negative impact of imbalanced data on the model performance. Results indicate the TL-GAT models outperformed GAT models, along with large coverage of applicability domains and interpretability. The constructed models were employed to identify PBMT chemicals from inventories consisting of about 1 × 106 chemicals. The developed TL-GAT framework with the LW function holds broad applicability across diverse tasks, especially those involving small and imbalanced data sets.
PMID:39680085 | DOI:10.1021/acs.est.4c11085
Chemosphere. 2025 Feb;370:143918. doi: 10.1016/j.chemosphere.2024.143918. Epub 2024 Dec 10.
ABSTRACT
Melamine has a high production volume today and is spread ubiquitously in the anthropogenic technosphere. It is released steadily to the water cycle by many sources. Even though melamine has low direct toxicity, chronic exposure can cause nephrolithiasis and disrupt the endocrine system. Most data on melamine is based on case studies with, when compared, partially contradictive implications. As melamine is a compound of many sources (SMS), very persistent, mobile (vPvM), and toxic (PMT) it has the potential to break through natural barriers posing a potential risk to drinking water resources. This study combines existing data with own measurements gathered through various individual monitoring campaigns with the aim to gain new insights into its environmental behaviour and hotspots. Samples from surface water bodies, groundwater, wastewater (treated, untreated), and soil samples were analysed regarding their melamine concentration via liquid chromatography coupled with tandem mass spectrometry (LC-MSMS). Besides three drinking water samples, melamine could be found in all water samples (n = 632) of this study, with a maximum concentration of 1289 ng/L in drinking water and 1120 ng/L in groundwater. While a constant baseline melamine concentration with an event-based release could be observed in most surface water bodies, higher concentrations towards Western Europe (urbanisation and chemical industry) was observed for wastewater. A similar pattern was found in the spatial distribution of melamine in agricultural soils towards an urban/suburban area. As, in general, melamine concentrations were higher towards urbans centers melamine can also be classified as an indicator of anthropogenic activity and urbanisation, but also spotlights on these areas as hotspots for potentially many compounds of the human technosphere. We call policy to shift from the existing one-size-fits-all solution to more flexible and risk-based approaches to prepare for future challenges.
PMID:39647792 | DOI:10.1016/j.chemosphere.2024.143918
Chemosphere. 2025 Feb;370:143918. doi: 10.1016/j.chemosphere.2024.143918. Epub 2024 Dec 10.
ABSTRACT
Melamine has a high production volume today and is spread ubiquitously in the anthropogenic technosphere. It is released steadily to the water cycle by many sources. Even though melamine has low direct toxicity, chronic exposure can cause nephrolithiasis and disrupt the endocrine system. Most data on melamine is based on case studies with, when compared, partially contradictive implications. As melamine is a compound of many sources (SMS), very persistent, mobile (vPvM), and toxic (PMT) it has the potential to break through natural barriers posing a potential risk to drinking water resources. This study combines existing data with own measurements gathered through various individual monitoring campaigns with the aim to gain new insights into its environmental behaviour and hotspots. Samples from surface water bodies, groundwater, wastewater (treated, untreated), and soil samples were analysed regarding their melamine concentration via liquid chromatography coupled with tandem mass spectrometry (LC-MSMS). Besides three drinking water samples, melamine could be found in all water samples (n = 632) of this study, with a maximum concentration of 1289 ng/L in drinking water and 1120 ng/L in groundwater. While a constant baseline melamine concentration with an event-based release could be observed in most surface water bodies, higher concentrations towards Western Europe (urbanisation and chemical industry) was observed for wastewater. A similar pattern was found in the spatial distribution of melamine in agricultural soils towards an urban/suburban area. As, in general, melamine concentrations were higher towards urbans centers melamine can also be classified as an indicator of anthropogenic activity and urbanisation, but also spotlights on these areas as hotspots for potentially many compounds of the human technosphere. We call policy to shift from the existing one-size-fits-all solution to more flexible and risk-based approaches to prepare for future challenges.
PMID:39647792 | DOI:10.1016/j.chemosphere.2024.143918
Sci Total Environ. 2025 Jan 1;958:177868. doi: 10.1016/j.scitotenv.2024.177868. Epub 2024 Dec 5.
ABSTRACT
There is increasing interest in chemicals which are persistent, mobile and toxic (PMT), primarily to protect drinking water. We present a tiered assessment of drinking water exposure and associated human health risks for 22 PMT substances. Worst-case exposure via drinking water is assumed to occur when wastewater is discharged to rivers which are then abstracted for water supply. Screening-level exposures assume daily per capita emissions based on REACH tonnage estimates, with removal in wastewater treatment calculated using SimpleTreat and no riverine dilution. Removal in water treatment was estimated for each substance assuming either conventional or advanced treatment processes. Higher tier spatially-resolved exposures used a gridded routing model which transfers chemical through the landscape based on flow directions derived from a 1 km digital elevation model. Emission was assumed to be proportional to population and no in-stream degradation was assumed. Exposures were calculated for 296 locations containing drinking water treatment works (WTWs) under mean discharge and Q95 (discharge exceeded 95% of the time). At low tiers, risk characterisation ratios (RCRs) were < 1 for all substances, assuming realistic tonnage and conventional treatment. If drinking water is assumed to represent only 20 % of total chemical intake, total RCRs (RCRT) were > 1 for three substances under conventional treatment but were < 1 for all substances under advanced treatment. Highest exposure and RCRs were predicted in highly populated areas with low dilution. RCRT values were > 1 for tetrachloroethylene (highest RCR) at up to 18 % of WTW locations under Q95 conditions assuming conventional treatment. However, RCRT was <1 for all locations assuming advanced treatment. Actual exposures will depend on catchment characteristics, but the model usefully allows prioritising higher risk chemicals and WTWs. Overall, the substances evaluated are unlikely to currently pose health risks, provided an appropriate level of water treatment is employed.
PMID:39642616 | DOI:10.1016/j.scitotenv.2024.177868
Water Res. 2025 Jan 1;268(Pt A):122607. doi: 10.1016/j.watres.2024.122607. Epub 2024 Oct 11.
ABSTRACT
Effect-Directed Analysis (EDA) was used to identify bioactive compounds in surface and well water from the Upper Rhine, and to evaluate their properties against the criteria set for Persistent, Mobile and Toxic (PMT) and very persistent and very mobile (vPvM) substances. A multi-layered solid-phase extraction was implemented to enrich a broad range of polar substances from the collected samples. The extracts were fractionated into 108 fractions and tested in the transthyretin (TTR)-binding assay measuring displacement of fluorescently labeled thyroxine (FITC-T4 TTR-binding assay) and the Aliivibrio fischeri bioluminescence (AFB) bioassay. Bioactive fractions guided the identification strategy using high-resolution mass spectrometry. Chemical features were systematically annotated using library databases and suspect lists, incorporating an automated assessment of the quality of each annotation. Based on this assessment, each chemical feature was assigned a specific identification confidence level. Identification of bioactive compounds was facilitated by using bioassay specific suspect lists that were extracted from an in-house developed database of positive and negative TTR-binding compounds and from a recently published database of active inhibitors of AFB. This resulted in the identification and confirmation of ten bioactive substances, including four evaluated as PMT and vPvM substances (diclofenac, trifloxystrobin acid, 6:2 FTSA and PFOA), and one as a potential PMT substance (4-aminoazobenzene). This study demonstrates the effectiveness of EDA in the identification of PMT/vPvM substances in the aquatic environment, facilitating their prioritization for comprehensive environmental risk assessment and possible regulation.
PMID:39454269 | DOI:10.1016/j.watres.2024.122607
Environ Toxicol Chem. 2024 Dec;43(12):2515-2527. doi: 10.1002/etc.5977. Epub 2024 Aug 26.
ABSTRACT
Aliphatic chlorinated hydrocarbons, notably tetrachloroethylene (also known as perchloroethylene [PCE]), are persistent, mobile, and toxic (PMT) and/or very persistent, mobile, and toxic (vPMT) groundwater pollutants, often exceeding safe drinking water thresholds. The present study delves into the groundwater risk assessment of PCE with a novel focus on the sensitivity of stygobitic species-organisms uniquely adapted to groundwater environments. Through a comparative analysis of the subchronic effects of PCE on the locomotion behavior of two copepod species, the stygobitic Moraria sp. and the nonstygobitic Bryocamptus zschokkei, we highlighted the inadequacy of the current European predicted-no-effect concentration of PCE for groundwater ecosystems. Our findings indicate significant behavioral impairments in both species at a concentration (32 ng/L PCE) well below the threshold deemed safe, suggesting that the current European guidelines for groundwater risk assessment may not adequately protect the unique biodiversity of groundwater habitats. Importantly, B. zschokkei demonstrated sensitivity to PCE comparable to or greater than that of the target stygobitic species, suggesting its utility as a substitute species in groundwater risk assessment. The present study adds to the limited research on the ecotoxicological sensitivity of groundwater species to PMT/vPMT chemicals and highlights the need for refined groundwater risk-assessment methodologies that consider the susceptibilities of stygobitic species. Environ Toxicol Chem 2024;43:2515-2527. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
PMID:39185674 | PMC:PMC11619749 | DOI:10.1002/etc.5977
Anal Chem. 2024 Sep 3;96(35):14150-14159. doi: 10.1021/acs.analchem.4c02041. Epub 2024 Aug 19.
ABSTRACT
Recycled textiles are becoming widely available to consumers as manufacturers adopt circular economy principles to reduce the negative impact of garment production. Still, the quality of the source material directly impacts the final product, where the presence of harmful chemicals is of utmost concern. Here, we develop a risk-based suspect and non-targeted screening workflow for the detection, identification, and prioritization of the chemicals present in consumer-based recycled textile products after manufacture and transport. We apply the workflow to characterize 13 recycled textile products from major retail outlets in Sweden. Samples were extracted and analyzed by liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS). In positive and negative ionization mode, 20,119 LC-HRMS features were detected and screened against persistent, mobile, and toxic (PMT) as well as other textile-related chemicals. Six substances were matched with PMT substances that are regulated in the European Union (EU) with a Level 2/3 confidence. Forty-three substances were confidently matched with textile-related chemicals reported for use in Sweden. For estimating the relative priority score, aquatic toxicity and concentrations were predicted for 7416 features with tandem mass spectra (MS2) and used to rank the non-targeted features. The top 10 substances were evaluated due to elevated environmental risk linked to the recycling process and potential release at end-of-life.
PMID:39160693 | PMC:PMC11375621 | DOI:10.1021/acs.analchem.4c02041
Sci Total Environ. 2024 Nov 15;951:175489. doi: 10.1016/j.scitotenv.2024.175489. Epub 2024 Aug 13.
ABSTRACT
Only about 100 disinfection byproducts (DBPs) have been tested for their potential aquatic toxicity. It is not known which specific DBPs, DBP main groups, and DBP subgroups are more toxic due to the lack of experimental toxicity data. Herein, high priority specific DBPs, DBP main groups, DBP subgroups, most sensitive model aquatic species, potential PBT and PMT (persistent, bioaccumulative/mobile, and toxic) DBPs were virtually screened for 1187 updated DBPs inventory. Priority setting based on experimental and predicted acute and chronic aquatic toxicity data found that the aromatic and alicyclic DBPs in four DBPs main groups showed high priority because larger proportions of aromatic and alicyclic DBPs are in high hazard categories (i.e. Acute and/or Chronic Toxic-1 or Toxic-2) according to the criteria in GHS system compared to the aliphatic and heterocyclic DBPs. The halophenols, estrogen-DBPs, nonhalogenated esters, and nonhalogenated aldehydes were recognized as high priority DBPs subgroups. For specific DBPs, 19 and 31 DBPs should be highly concerned in the future study because both acute and chronic toxicity of those DBPs to all of the three aquatic life (algae, Daphnia magna, fish) were classified as Toxic-1 and Toxic-2, respectively. The Daphnia magna and algae were sensitive to the acute toxicity of DBPs, while the fish and Daphnia magna were sensitive to the chronic toxicity of DBPs. One potential PBT (Tetrachlorobisphenol A) and four potential PMT DBPs were identified. For verification, the acute toxicity of four DBPs on three aquatic organism were performed, and their tested acute toxicity data to three aquatic organisms were consistent with the predictions. Our results could be beneficial to government regulators to adopt effective measures to limit the discharge of high priority DBPs and help the scientific community to develop or improve disinfection processes to reduce the production of high priority DBPs.
PMID:39142401 | DOI:10.1016/j.scitotenv.2024.175489
Sci Total Environ. 2024 Oct 10;946:173884. doi: 10.1016/j.scitotenv.2024.173884. Epub 2024 Jun 15.
ABSTRACT
Soft plastic lures (SPLs) are commonly used artificial lures in recreational angling. Anglers regularly lose SPLs while fishing and there is little knowledge about the environmental impacts of lost SPLs. As with other plastic items, SPLs contain phthalates and other persistent additives that may leach into water. In this study, 16 randomly chosen SPLs of common models were analyzed for the leaching of persistent, water-soluble plastic additives, including phthalates. The estrogenicity of sample extracts from a subsample of 10 SPLs was assessed using luciferase reporter gene bioassays. Over a period of 61 days, 10 of the 16 SPLs leached the targeted phthalates dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP) and di-n-butyl phthalate (DnBP) at median detectable concentrations ranging from 10 ng/g sample BBP to a median of 1001 ng/g DMP as well as 45 persistent, mobile, and toxic (PMT) plastic additives. DEP was detected most frequently in 8 SPLs, followed by BBP (2 SPLs), DMP (2 SPLs) and DnBP (1 SPL). The extract from one SPL with comparatively low phthalate and PMT plastic additive levels was active in the bioassay, indicating high endocrine-disruptive potential, presumably due to unknown additives that were not among the target substances of the methodology used in this study. The study was supplemented by a mail survey among anglers, in which attitudes of anglers towards SPLs were investigated. The survey indicated that SPL loss is a common event during angling. Most participants were concerned about potential ecological impacts of SPLs, wanted the ingredients of SPLs to be labelled and supported legal restrictions concerning toxic ingredients of SPLs. The study shows that SPLs are a potential source of environmental pollution, may pose human health risks and need further investigation, considering the frequent use of SPLs in recreational angling.
PMID:38885719 | DOI:10.1016/j.scitotenv.2024.173884
Environ Sci Eur. 2024;36(1):102. doi: 10.1186/s12302-024-00919-4. Epub 2024 May 21.
ABSTRACT
BACKGROUND: Persistent, mobile and toxic (PMT), or very persistent and very mobile (vPvM) substances are a wide class of chemicals that are recalcitrant to degradation, easily transported, and potentially harmful to humans and the environment. Due to their persistence and mobility, these substances are often widespread in the environment once emitted, particularly in water resources, causing increased challenges during water treatment processes. Some PMT/vPvM substances such as GenX and perfluorobutane sulfonic acid have been identified as substances of very high concern (SVHCs) under the European Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulation. With hundreds to thousands of potential PMT/vPvM substances yet to be assessed and managed, effective and efficient approaches that avoid a case-by-case assessment and prevent regrettable substitution are necessary to achieve the European Union's zero-pollution goal for a non-toxic environment by 2050.
MAIN: Substance grouping has helped global regulation of some highly hazardous chemicals, e.g., through the Montreal Protocol and the Stockholm Convention. This article explores the potential of grouping strategies for identifying, assessing and managing PMT/vPvM substances. The aim is to facilitate early identification of lesser-known or new substances that potentially meet PMT/vPvM criteria, prompt additional testing, avoid regrettable use or substitution, and integrate into existing risk management strategies. Thus, this article provides an overview of PMT/vPvM substances and reviews the definition of PMT/vPvM criteria and various lists of PMT/vPvM substances available. It covers the current definition of groups, compares the use of substance grouping for hazard assessment and regulation, and discusses the advantages and disadvantages of grouping substances for regulation. The article then explores strategies for grouping PMT/vPvM substances, including read-across, structural similarity and commonly retained moieties, as well as the potential application of these strategies using cheminformatics to predict P, M and T properties for selected examples.
CONCLUSIONS: Effective substance grouping can accelerate the assessment and management of PMT/vPvM substances, especially for substances that lack information. Advances to read-across methods and cheminformatics tools are needed to support efficient and effective chemical management, preventing broad entry of hazardous chemicals into the global market and favouring safer and more sustainable alternatives.
PMID:38784824 | PMC:PMC11108893 | DOI:10.1186/s12302-024-00919-4
Chemosphere. 2024 Jul;360:142391. doi: 10.1016/j.chemosphere.2024.142391. Epub 2024 May 20.
ABSTRACT
This study addresses the gap in freshwater ecotoxicological characterization factors (CFs) for Persistent, Mobile, and Toxic (PMT) and Very Persistent and Very Mobile (vPvM) substances. These CFs are vital for integrating the ecotoxicity impacts of these chemicals into life cycle assessments. Our goals are twofold: first, to calculate experimental freshwater CFs for PMT/vPvM substances listed by the German Environment Agency (UBA); second, to compare these CFs with those from the USEtox database. The expanded UBA list includes 343 PMT/vPvM substances, each representing a unique chemical structure, and linked to 474 REACH-registered substances. This study successfully computed CFs for 244 substances, with 107 overlapping the USEtox database and 137 being new. However, ecotoxicity data limitations prevented CF determination for 97 substances. This research enhances our understanding of freshwater CFs for PMT/vPvM substances, covering 72% of UBA's 343 PMT/vPvM substances. Data scarcity remains a significant challenge, which invariably impedes CF calculations. Notably, the disparities observed between CF values in the USEtox database and those derived in this research largely stem from variations in ecotoxicity data. Consequently, this research underscores the dynamic nature of CFs for substances, emphasizing the need for regular updates to ensure their accuracy and relevance.
PMID:38777192 | DOI:10.1016/j.chemosphere.2024.142391
Environ Sci Technol. 2024 May 7;58(18):7710-7718. doi: 10.1021/acs.est.4c00125. Epub 2024 Apr 24.
ABSTRACT
When chemical pollutants enter the environment, they can undergo diverse transformation processes, forming a wide range of transformation products (TPs), some of them benign and others more harmful than their precursors. To date, the majority of TPs remain largely unrecognized and unregulated, particularly as TPs are generally not part of routine chemical risk or hazard assessment. Since many TPs formed from oxidative processes are more polar than their precursors, they may be especially relevant in the context of persistent, mobile, and toxic (PMT) and very persistent and very mobile (vPvM) substances, which are two new hazard classes that have recently been established on a European level. We highlight herein that as a result, TPs deserve more attention in research, chemicals regulation, and chemicals management. This perspective summarizes the main challenges preventing a better integration of TPs in these areas: (1) the lack of reliable high-throughput TP identification methods, (2) uncertainties in TP prediction, (3) inadequately considered TP formation during (advanced) water treatment, and (4) insufficient integration and harmonization of TPs in most regulatory frameworks. A way forward to tackle these challenges and integrate TPs into chemical management is proposed.
PMID:38656189 | PMC:PMC11080041 | DOI:10.1021/acs.est.4c00125
Environ Sci Technol. 2024 Apr 16;58(15):6814-6824. doi: 10.1021/acs.est.4c00577. Epub 2024 Apr 6.
ABSTRACT
Identifying persistent, mobile, and toxic (PMT) substances from synthetic chemicals is critical for chemical management and ecological risk assessment. Inspired by the triazine analogues (e.g., atrazine and melamine) in the original European Union's list of PMT substances, the occurrence and compositions of alkylamine triazines (AATs) in the estuarine sediments of main rivers along the eastern coast of China were comprehensively explored by an integrated strategy of target, suspect, and nontarget screening analysis. A total of 44 AATs were identified, of which 23 were confirmed by comparison with authentic standards. Among the remaining tentatively identified analogues, 18 were emerging pollutants not previously reported in the environment. Tri- and di-AATs were the dominant analogues, and varied geographic distributions of AATs were apparent in the investigated regions. Toxic unit calculations indicated that there were acute and chronic risks to algae from AATs on a large geographical scale, with the antifouling biocide cybutryne as a key driver. The assessment of physicochemical properties further revealed that more than half of the AATs could be categorized as potential PMT and very persistent and very mobile substances at the screening level. These results highlight that AATs are a class of PMT substances posing high ecological impacts on the aquatic environment and therefore require more attention.
PMID:38581381 | DOI:10.1021/acs.est.4c00577
Environ Sci Technol. 2024 Apr 9;58(14):6149-6157. doi: 10.1021/acs.est.4c01201. Epub 2024 Apr 1.
ABSTRACT
The global management for persistent, mobile, and toxic (PMT) and very persistent and very mobile (vPvM) substances has been further strengthened with the rapid increase of emerging contaminants. The development of a ready-to-use and publicly available tool for the high-throughput screening of PMT/vPvM substances is thus urgently needed. However, the current model building with the coupling of conventional algorithms, small-scale data set, and simplistic features hinders the development of a robust model for screening PMT/vPvM with wide application domains. Here, we construct a graph convolutional network (GCN)-enhanced model with feature fusion of a molecular graph and molecular descriptors to effectively utilize the significant correlation between critical descriptors and PMT/vPvM substances. The model is built with 213,084 substances following the latest PMT classification criteria. The application domains of the GCN-enhanced model assessed by kernel density estimation demonstrate the high suitability for high-throughput screening PMT/vPvM substances with both a high accuracy rate (86.6%) and a low false-negative rate (6.8%). An online server named PMT/vPvM profiler is further developed with a user-friendly web interface (http://www.pmt.zj.cn/). Our study facilitates a more efficient evaluation of PMT/vPvM substances with a globally accessible screening platform.
PMID:38556993 | DOI:10.1021/acs.est.4c01201
iScience. 2024 Jan 24;27(2):109012. doi: 10.1016/j.isci.2024.109012. eCollection 2024 Feb 16.
ABSTRACT
Various synthetic substances were utilized in large quantities during the recent coronavirus pandemic, COVID-19. Some of these chemicals could potentially enter drinking water sources. Persistent, mobile, and toxic (PMT) substances have been recognized as a threat to drinking water resources. It has not yet been assessed how many COVID-19 related substances could be considered PMT substances. One reason is the lack of high-quality experimental data for the identification of PMT substances. To solve this problem, we applied a machine learning model to identify the PMT substances among COVID-19 related chemicals. The optimal model achieved an accuracy of 90.6% based on external test data. The model interpretation and causal inference indicated that our approach understood causation between PMT properties and molecular descriptors. Notably, the screening results showed that over 60% of the COVID-19 chemicals considered are candidate PMT substances, which should be prioritized to prevent undue pollution of water resources.
PMID:38352231 | PMC:PMC10863329 | DOI:10.1016/j.isci.2024.109012
J Hazard Mater. 2024 Mar 5;465:133498. doi: 10.1016/j.jhazmat.2024.133498. Epub 2024 Jan 12.
ABSTRACT
Substantially polluted tunnel wash water (TWW) is produced during road tunnel maintenance. Previous literature has reported the presence of trace elements and polycyclic aromatic hydrocarbons (PAHs). However, it was hypothesized that other organic pollutants are present, and more knowledge is needed to prevent environmental harm. This study reveals for the first time the presence of four short- and 17 long-chained per- and polyfluoroalkyl substances (PFASs), three benzothiazoles (BTHs), six benzotriazoles (BTRs), four bisphenols, and four benzophenones in TWW from a Norwegian road tunnel over a period of three years. Concentrations of PAHs, PFASs, BTHs, and BTRs were higher than previously reported in e.g., road runoff and municipal wastewater. Trace elements and PAHs were largely particulate matter associated, while PFASs, BTHs, BTRs, bisphenols, and benzophenones were predominantly dissolved. 26 of the determined contaminants were classified as persistent, mobile, and toxic (PMT) and are of special concern. It was recommended that regulations for TWW quality should be expanded to include PMT contaminants (such as PFPeA, PFBS, BTR, and 4-OH-BzP) and markers of pollution (like 2-M-BTH, 2-OH-BTH, and 2-S-BTH from tire wear particles). These findings highlight the need to treat TWW before discharge into the environment, addressing both, particulate matter associated and dissolved contaminants.
PMID:38232556 | DOI:10.1016/j.jhazmat.2024.133498
SAR QSAR Environ Res. 2023 Oct-Dec;34(12):1023-1039. doi: 10.1080/1062936X.2023.2287516. Epub 2023 Dec 4.
ABSTRACT
A study of Quantitative Structure Activity Relationship (QSAR) was performed to assess the possible adverse effects of 25 pharmaceuticals commonly found in the Brazilian water compartments and to establish a ranking of environmental concern. The occurrence (O), the persistence (P), the mobility (M), and the toxicity (T) of these compounds in the Brazilian drinking water reservoirs were evaluated. Moreover, to verify the predicted OPMT dataset outcomes, a quality index (QI) was also developed and applied. The main results showed that: (i) after in silico predictions through VEGA QSAR, 19 from 25 pharmaceuticals consumed in Brazil were classified as persistent; (ii) moreover, after in silico predictions through OPERA QSAR, 15 among those 19 compounds considered persistent, were also classified as mobile or very mobile. On the other hand, the results of toxicity indicate that only 9 pharmaceuticals were classified with the highest toxicity level. Ultimately, the QI of 7 from 25 pharmaceuticals were categorized as 'optimal'; 15 pharmaceuticals were categorized as 'good'; and only 3 pharmaceuticals were categorized as 'regular'. Therefore, based on the QI criteria used, it is possible to assume that this OPMT prediction dataset had a good reliability. Efforts to reduce emissions of OPMT-pharmaceuticals in Brazilian drinking water reservoirs are encouraged.
PMID:38047444 | DOI:10.1080/1062936X.2023.2287516
Environ Sci Technol. 2023 Oct 3;57(39):14694-14706. doi: 10.1021/acs.est.3c02945. Epub 2023 Sep 21.
ABSTRACT
Persistent, mobile, and toxic (PMT) substances are affecting the safety of drinking water and are threatening the environment and human health. Many PMT substances are used in industrial processing or consumer products, but their sources and emissions mostly remain unclear. This study presents a long-term source distribution and emission estimation of melamine, a high-production-volume PMT substance of emerging global concern. The results indicate that in China, approximately 1858.7 kilotonnes (kt) of melamine were released into the water (∼58.9%), air (∼27.0%), and soil systems (∼14.1%) between 1995 and 2020, mainly from its production and use in the decorative panels, textiles, and paper industries. The textile and paper industries have the highest emission-to-consumption ratios, with more than 90% emissions per unit consumption. Sewage treatment plants are the largest source of melamine in the environment for the time being, but in-use products and their wastes will serve as significant melamine sources in the future. The study prompts priority action to control the risk of PMT substances internationally.
PMID:37734035 | PMC:PMC11017250 | DOI:10.1021/acs.est.3c02945
Water Res. 2023 Oct 1;244:120470. doi: 10.1016/j.watres.2023.120470. Epub 2023 Aug 9.
ABSTRACT
Determining which substances on the global market could be classified as persistent, mobile and toxic (PMT) substances or very persistent, very mobile (vPvM) substances is essential to prevent or reduce drinking water contamination from them. This study developed machine learning models based on different molecular descriptors (MDs) and defined applicability domains for the screening of PMT/vPvM substances. The models were trained with 3111 substances with expert weight-of-evidence based PMT/vPvM hazard classifications that considered the highest quality data available. The model was based on the hypothesis that PMT/vPvM substances contain similar MDs, representative of chemical structures resistant to degradation, be associated with low sorption (or high-water solubility) and in some cases be associated with known toxic mechanisms. All possible model combinations were tested by integrating different molecular description methods, data balancing strategies and machine learning algorithms. Our model allows one-step prediction of candidate PMT/vPvM substances, and our method was compared with the approach predicting P, M and T separately (i.e. three-step prediction). The results showed that the one-step model achieved a higher accuracy of 92% for PMT/vPvM identification (i.e. positive samples) for an internal test set, and also resulted in a higher accuracy of 90% for an external test set of chemical pollutants detected in Taihu Lake, China. Furthermore, prediction mechanism of the model was interpreted by Shapley additive explanations (SHAP). This work presents an advance of big data in silico screening models for the identification of substances that potentially meet the PMT/vPvM criteria.
PMID:37595327 | DOI:10.1016/j.watres.2023.120470
Sci Total Environ. 2023 Dec 10;903:166240. doi: 10.1016/j.scitotenv.2023.166240. Epub 2023 Aug 11.
ABSTRACT
Emerging organic contaminants (EOCs) are a vast group of often (very)persistent, (very)mobile and toxic (PMT/vPvM) substances that are continuously released worldwide, posing environmental and human health risks. Research on occurrence and behavior of EOCs in karst is in its infancy, thus policy measures and legislative control of these compounds in groundwater are still lacking. The Dinaric karst aquifers are an essential source of drinking water for almost half of Croatia's territory. Intense karstification, complex heterogeneous characteristics, and high fracture-cavernous porosity result in rapid, far-reaching groundwater flow and large karst springs, but also high intrinsic vulnerability due to low contaminant attenuation. To prioritize future monitoring and establish appropriate thresholds for EOCs detected in Croatian karst drinking water resources, in silico tools based on quantitative structure-activity relationships were used in PBT (persistence, bioaccumulation, and toxicity) and PMT/vPvM analyzes, while toxicological assessment helped identify potential threats to human health. In 33 samples collected during two sampling campaigns in 2019 at 16 karst springs and one lake used for water supply, we detected 65 compounds (EOCs and some legacy chemicals), of which 7 were classified as potentially PBT or vPvB compounds (PFOS, PFHxS, PFHpA, PFOA, PFNA, boscalid, and azoxystrobin), while only 2 compounds were assessed as not PMT/vPvM. This finding underlines that most of detected EOCs potentially endanger karst (ground)water ecosystems and important drinking water sources in Croatia. Comparison of maximum concentrations with existing or derived drinking water guideline values revealed how 2 of 65 detected compounds represent a potential risk to human health at lifelong exposure (sulfadiazine and hydrochlorothiazide), while 5 chemicals warrant additional human health impacts studies and groundwater monitoring. Although most compounds do not individually pose a significant risk to human health at current environmental levels, their potential synergistic and long-term effects remain unknown.
PMID:37572907 | DOI:10.1016/j.scitotenv.2023.166240
Environ Pollut. 2023 Oct 15;335:122263. doi: 10.1016/j.envpol.2023.122263. Epub 2023 Jul 26.
ABSTRACT
Plastic additives are a diverse group of chemical compounds added to plastic products to give them their unique physical-chemical properties. Persistent, mobile, and toxic (PMT) plastic additives are a highly polar, environmentally stable sub-group of plastic additives with a variety of uses in plastic products. Due to their mobility into water, they can pose a significant long-term risk to the aquatic environment. Despite the potential threat, PMT plastic additives remain largely unregulated and under-studied. Notably, there is a need for dedicated analytical methodology and leaching studies to determine their potential emission from plastic products. Here we present an optimized leaching protocol and novel instrumental analysis method for the screening of 124 PMT plastic additives registered for use in Canada using high performance liquid chromatography with quantitative time-of-flight mass spectrometry (HPLC-QToF-MS). The analytical method covered a log Kow/Dow range between 0.21 and 6.02, which covered 72% of the PMT plastic additives used in Canada. A total of 52 PMT plastic additive suspects were leached in the optimization experiments, 44 of which were unique based on accurate mass and retention time. The conditions that resulted in the greatest numbers of PMT plastic additives leached were lake water, UV light exposure, and a timeframe of approximately 30 days. The analytical and leaching methods presented here offer new tools to study PMT plastic additives and assess their leaching in an environmentally relevant matrix, which can inform monitoring, threat assessment, and regulatory efforts moving forward.
PMID:37499969 | DOI:10.1016/j.envpol.2023.122263
Environ Int. 2023 Aug;178:108042. doi: 10.1016/j.envint.2023.108042. Epub 2023 Jun 21.
ABSTRACT
Over a third of the global chemical production and sales occurred in China, which make effective assessment and management for chemicals produced by China's chemical industry essential not just for China but for the world. Here, we systematical assessed the persistence (P), bioaccumulation (B), mobility (M) and toxicity (T) potency properties for the chemicals listed in Inventory of Existing Chemical Substances of China (IECSC) via experimental data retrieved from large scale databases and in silico data generated with well-established models. Potential PBT, PMT and PB&MT substances were identified. High risk potentials were highlighted for groups of synthetic intermediates, raw materials, as well as a series of biocides. The potential PBT and PMT synthetic intermediates and/or raw materials unique to the IECSC were dominated with organofluorines, for example, the intermediates used as electronic light-emitting materials. Meanwhile, the biocides unique to the IECSC were mainly organochlorines. Some conventional classes of insecticides, such as organochlorines and pyrethroids, were classified as being of high concern. We further identified a group of PB&MT substances that were considered to be both "bioaccumulative" and "mobile". Their properties and common substructures for several major clusters were characterized. The present results prioritized groups of substances with high potentials to cause adverse effects to the environment and humans, many of which have not yet been fully recognized.
PMID:37399767 | DOI:10.1016/j.envint.2023.108042
J Hazard Mater. 2023 Sep 15;458:131854. doi: 10.1016/j.jhazmat.2023.131854. Epub 2023 Jun 14.
ABSTRACT
Persistent, mobile, and toxic chemicals (PMT), such as the antimycotic climbazole-(CBZ), proliferate in water cycle and imperil drinking water quality, sparking off research about their environmental fate. Unlike the parent compound, its transformation products-(TPs) are scarcely investigated, much less as PMTs. To this end, phototransformation of CBZ was investigated. A novel suspect-screening workflow was developed and optimized by cross-comparing the results of the identified photo-TPs against literature data to create an enhanced HRMS-database for environmental investigations of CBZ/TPs in the water cycle. In total, 24 TPs were identified, 14 of which are reported for the first time. Isomerism, dechlorination, hydroxylation, and cleavage of the ether or C-N bond are suggested as the main transformation routes. A screening of CBZ/TPs was conducted in wastewater, leachates, surface, and groundwater, revealing a maximum concentration of 464.8 ng/L in groundwater. In silico and in vitro methods were used for toxicity assessment, indicating toxicity for CBZ and some TPs. Seemingly, CBZ is rightly considered as PMT, and a higher potential to occur in surface or groundwater than non-PM chemicals appears. Likewise, the occurrence of TPs due to PMT properties or emission patterns was evaluated.
PMID:37354716 | DOI:10.1016/j.jhazmat.2023.131854
Huan Jing Ke Xue. 2023 Jun 8;44(6):3017-3023. doi: 10.13227/j.hjkx.202207182.
ABSTRACT
Persistent, mobile, and toxic or very persistent and very mobile (PMT/vPvM) chemicals have been widely detected in surface water, groundwater, and drinking water around the world and are important emerging contaminants that may significantly affect human health and the environment in the future. According to the identification criteria proposed by the European Union, there are thousands of PMT/vPvM substances in existing chemicals, covering a wide range of applications, including dozens of high-yield industrial chemicals such as melamine. PMT/vPvM chemicals can be discharged into the environment through farmland runoff, industrial wastewater, and domestic sewage, and sewage treatment plants are currently considered to be their main discharge route. It is difficult to effectively remove PMT/vPvM chemicals through the current conventional water treatment technology; they can exist in the water circulation system of the urban human settlement environment for a long time, endangering the safety of drinking water and the ecosystem. The European Union has taken the lead in introducing PMT/vPvM chemicals specifically into the priority areas of the current chemical risk management system. At present, there are still many potential PMT/vPvM chemicals in the environment, and their monitoring methods need to be further improved. It will take time for the identification of substances, the scope of categories, and the establishment of lists. Studies on the environmental fate and exposure of PMT/vPvM in various regions of the world are still very limited, and research on the potential, long-term ecotoxicity, and human health hazard effects remains scarce. At the same time, the research and development of substitute or alternative technologies, as well as environmental engineering treatment technologies such as sewage treatment and contaminated site remediation, will become an urgent need for future PMT/vPvM risk scientific research and management decisions.
PMID:37309920 | DOI:10.13227/j.hjkx.202207182
Environ Sci Technol. 2023 Jun 6;57(22):8335-8346. doi: 10.1021/acs.est.2c07774. Epub 2023 May 21.
ABSTRACT
Antimicrobial transformation products (ATPs) in the environment have raised extensive concerns in recent years due to their potential health risks. However, only a few ATPs have been investigated, and most of the transformation pathways of antimicrobials have not been completely elucidated. In this study, we developed a nontarget screening strategy based on molecular networks to detect and identify ATPs in pharmaceutical wastewater. We identified 52 antimicrobials and 49 transformation products (TPs) with a confidence level of three or above. Thirty of the TPs had not been previously reported in the environment. We assessed whether TPs could be classified as persistent, mobile, and toxic (PMT) substances based on recent European criteria for industrial substances. Owing to poor experimental data, definitive PMT classifications could not be established for novel ATPs. PMT assessment based on structurally predictive physicochemical properties revealed that 47 TPs were potential PMT substances. These results provide evidence that novel ATPs should be the focus of future research.
PMID:37211672 | DOI:10.1021/acs.est.2c07774
Sci Total Environ. 2023 Sep 20;892:164264. doi: 10.1016/j.scitotenv.2023.164264. Epub 2023 May 19.
ABSTRACT
Green infrastructure drainage systems are innovative treatment units that capture and treat stormwater. Unfortunately, highly polar contaminants remain challenging to remove in conventional biofilters. To overcome treatment limitations, we assessed the transport and removal of stormwater vehicle-related organic contaminants with persistent, mobile, and toxic (in short: PMTs) properties, such as 1H-benzotriazole, NN'-diphenylguanidine, and hexamethoxymethylmelamine (PMT precursor), using batch experiments and continuous-flow sand columns amended with pyrogenic carbonaceous materials, like granulated activated carbon (GAC) or wheat-straw derived biochar. Our results indicated that all investigated contaminants were subjected to nonequilibrium interactions in sand-only and geomedia-amended columns, with kinetic effects upon transport. Experimental breakthrough curves could be well described by a one-site kinetic transport model assuming saturation of sorption sites, which we inferred could occur due to dissolved organic matter fouling. Furthermore, from both batch and column experiments, we found that GAC could remove contaminants significantly better than biochar with higher sorption capacity and faster sorption kinetics. Hexamethoxymethylmelamine, with the lowest organic carbon-water partition coefficient (KOC) and largest molecular volume among target chemicals, exhibited the lowest affinity in both carbonaceous adsorbents based on estimated sorption parameters. Results suggest that sorption of investigated PMTs was likely driven by steric and hydrophobic effects, and coulombic and other weak intermolecular forces (e.g., London-van der Waals, H-bonding). Results from extrapolating our data to a 1-m depth geomedia-amended sand filter suggested that GAC and biochar could enhance the removal of organic contaminants in biofilters and last for more than one decade. Overall, our work is the first to study treatment alternatives for NN'-diphenylguanidine and hexamethoxymethylmelamine, and contributes to better PMT contaminant removal strategies in environmental applications.
PMID:37209730 | DOI:10.1016/j.scitotenv.2023.164264
Environ Sci Process Impacts. 2023 Jun 21;25(6):1067-1081. doi: 10.1039/d3em00025g.
ABSTRACT
Measures are needed to protect water sources from substances that are mobile, persistent and toxic (PMT) or very persistent and very mobile (vPvM). PMT/vPvM substances are used in a diverse range of applications, including consumer products. The combined application of the essential-use and functional substitution concepts has been proposed to phase out substances of concern and support the transition to safer and more sustainable chemicals, a key goal of the European Commission's Chemicals Strategy for Sustainability. Here, we first identified the market share of PMT/vPvM containing cosmetic products. We found that 6.4% of cosmetic products available on the European market contain PMT or vPvM substances. PMT/vPvM substances were most often found in hair care products. Based on their high occurrence, the substances Allura red (CAS 25956-17-6), benzophenone-4 (CAS 4065-45-6) and climbazole (CAS 38083-17-9) were selected as case-studies for assessment of their functionality, availability of safer alternatives and essentiality. Following the functional substitution framework, we found that the technical function of Allura red was not necessary for the performance of some cosmetic products, making the use non-essential. For other applications of Allura red, as well as all applications of benzophenone-4 and climbazole, the technical function of the chemical was considered necessary for the performance. Via the alternative's assessment procedure, which used experimental and in silico data and three different multicriteria decision analysis (MCDA) strategies, safer alternatives were identified for all case-study chemicals. All assessed uses of PMT/vPvM substances were thus deemed non-essential and should consequently be phased out.
PMID:37199459 | DOI:10.1039/d3em00025g
Sci Total Environ. 2023 Sep 1;889:164170. doi: 10.1016/j.scitotenv.2023.164170. Epub 2023 May 16.
ABSTRACT
Persistent, mobile and toxic (PMT), and very persistent and very mobile (vPvM) substances pose a threat to the water cycle but are often not covered in conventional environmental monitoring programs. Within this realm of substances, one compound class of concern are pesticides and their transformation products as they are deliberately introduced into the environment. To detect very polar anionic substances, including many pesticide transformation products with log DOW values ranging between -7.4 and 2.2, an ion chromatography high-resolution mass spectrometry method was developed in this study. Since inorganic anions, such as chloride and sulfate, interfere with the analysis of organic species, their removal via precipitation with Ba/Ag/H cartridges was assessed. To improve LOQs, vacuum-assisted evaporative concentration (VEC) was evaluated. By using VEC and removing inorganic salt ions, the median LOQ improved from 100 ng/L in evian® water without sample treatment to 10 ng/L after enrichment and 30 ng/L in karst groundwater. Using this method, twelve out of 64 substances covered by the final method were found in karst groundwater in concentrations of up to 5600 ng/L, and seven exceeded 100 ng/L. To the authors' knowledge, the dimethenamid TP M31 and chlorothalonil TP SYN548008 were detected for the first time in groundwater samples. The coupling to a high-resolution mass spectrometer also allows for non-target screening and hence, this method presents a powerful tool to tackle PMT/vPvM substances.
PMID:37201846 | DOI:10.1016/j.scitotenv.2023.164170
Sci Total Environ. 2023 Aug 15;886:163921. doi: 10.1016/j.scitotenv.2023.163921. Epub 2023 May 8.
ABSTRACT
Persistent and mobile (PM) substances are able to spread quickly in the water cycle and were thus identified as potentially problematic for the environment and water quality. If also toxic (PMT) or very persistent and very mobile (vPvM) their regulation under REACH as substances of very high concern is foreseen. Yet, knowledge on the effectiveness of advanced wastewater treatment in removing PM-substances from WWTP effluents is limited to few rather well-known chemicals. The occurrence and behavior of 111 suspected and known PM-substances was investigated in two wastewater treatment plants employing either powdered activated carbon (PAC, full-scale) or ozonation with subsequent sand/anthracite filtration (pilot-scale) and an additional granular activated carbon (GAC) filtration was investigated. 72 of the 111 PM-substances analyzed were detected at least once in the secondary effluent of either wastewater treatment plant, resulting in total concentrations of 104 μg/L and 40 μg/L, respectively. While PAC removed 32 % of PM-substances well, the total PM burden in the effluent was only reduced from 103 μg/L to 87 μg/L. Ozonation and the subsequent sand/anthracite filtration was able to reduce the PM burden in wastewater from 40 μg/L to 19 μg/L, showing a higher removal efficacy than PAC in this study. The additional GAC filtration further reduced the total PM-concentration to 13 μg/L. Among the investigated PM-chemicals detected were constituents of ionic liquids: The anion hexafluorophosphate was one of few chemicals that was detected in effluent concentrations >1 μg/L and could not be removed by the processes studied, showing that for some chemicals preventive actions may be required.
PMID:37164071 | DOI:10.1016/j.scitotenv.2023.163921
Environ Res. 2023 Jul 15;229:115980. doi: 10.1016/j.envres.2023.115980. Epub 2023 Apr 23.
ABSTRACT
Accelerated urbanization and industrialization have led to an alarming increase in the generation of wastewater with complex chemical contents. Industrial wastewaters are often a primary source of water contamination. The chemical characterization of different industrial wastewater types is an essential task to interpret the chemical fingerprints of wastewater to identify pollution sources and develop efficient water treatment strategies. In this study, we conduct a non-target chemical analysis for the source characterization of different industrial wastewater samples collected from a chemical industrial park (CIP) located in southeast China. The chemical screening identified volatile and semi-volatile organic compounds that included dibutyl phthalate at a maximum concentration of 13.4 μg/L and phthalic anhydride at 35.9 μg/L. Persistent, mobile, and toxic (PMT) substances among the detected organic compounds were identified and prioritized as high-concern contaminants given their impact on drinking water resources. Moreover, a source analysis of the wastewater collected from the wastewater outlet station indicated that the dye production industry contributed the largest quantities of toxic contaminates (62.6%), and this result was consistent with the ordinary least squares and heatmap results. Thus, our study utilized a combined approach of a non-target chemical analysis, a pollution source identification method, and a PMT assessment of different industrial wastewater samples collected from the CIP. The results of the chemical fingerprints of different industrial wastewater types as well as the results of the PMT assessment benefit risk-based wastewater management and source reduction strategies.
PMID:37098386 | DOI:10.1016/j.envres.2023.115980
J Hazard Mater. 2023 Jul 5;453:131376. doi: 10.1016/j.jhazmat.2023.131376. Epub 2023 Apr 11.
ABSTRACT
Persistent, mobile, and toxic (PMT) substances have recently garnered increased attention by environmental researchers, the water sector and environmental protection agencies. In this study, acute and chronic species sensitivity distributions (SSDs) were retrieved from literature data for previously quantified contaminants of emerging concern (CECs) in Swedish surface waters (n = 92) and risk quotients (RQ) were calculated. To better understand the characteristics of the detected CECs in non-urban lake sites (n = 71), these compounds were checked against established criteria for potentially toxic PMs (PM(T)s) and occurrence in the aquatic environment, respectively. For the CECs with missing SSDs (n = 15 [acute], n = 41 [chronic]), ecotoxicity data were extracted for eight taxonomic groups, and if data were sufficient (n ≥ 3), SSDs were derived. The retrieved and newly developed SSDs were then used in an environmental hazard assessment (EHA) in the investigated Swedish rivers and lakes. In the rivers, 8 CECs had RQ> 1 in at least one location, and 20 CECs posed a moderate risk (0.01 < RQ < 1). In total, 21 of the 71 detected substances had already been identified as PM(T)/vPvM substances. Our study shows the importance of studying field data at large spatial scale to reveal potential environmental hazards far from source areas.
PMID:37094447 | DOI:10.1016/j.jhazmat.2023.131376
Sci Total Environ. 2023 Jul 1;880:163343. doi: 10.1016/j.scitotenv.2023.163343. Epub 2023 Apr 6.
ABSTRACT
Persistent, Mobile, and Toxic (PMT) and very persistent and very mobile (vPvM) substances are a growing threat to water security and safety. Many of these substances are distinctively different from other more traditional contaminants in terms of their charge, polarity, and aromaticity. This results in distinctively different sorption affinities towards traditional sorbents such as activated carbon. Additionally, an increasing awareness on the environmental impact and carbon footprint of sorption technologies puts some of the more energy-intensive practices in water treatment into question. Commonly used approaches may thus need to be readjusted to become fit for purpose to remove some of the more challenging PMT and vPvM substances, including for example short chained per- and polyfluoroalkyl substances (PFAS). We here critically review the interactions that drive sorption of organic compounds to activated carbon and related sorbent materials and identify opportunities and limitations of tailoring activated carbon for PMT and vPvM removal. Other less traditional sorbent materials, including ion exchange resins, modified cyclodextrins, zeolites and metal-organic frameworks are then discussed for potential alternative or complementary use in water treatment scenarios. Sorbent regeneration approaches are evaluated in terms of their potential, considering reusability, potential for on-site regeneration, and potential for local production. In this context, we also discuss the benefits of coupling sorption to destructive technologies or to other separation technologies. Finally, we sketch out possible future trends in the evolution of sorption technologies for PMT and vPvM removal from water.
PMID:37030383 | DOI:10.1016/j.scitotenv.2023.163343
Sci Total Environ. 2023 Jun 15;877:162618. doi: 10.1016/j.scitotenv.2023.162618. Epub 2023 Mar 11.
ABSTRACT
The EU is planning to restrict the manufacture, placing on the market and use of per- and polyfluoroalkyl substances (PFASs) as a class. For such a broad regulatory approach, a lot of different data are required, including data on the hazardous properties of PFASs. Here, we analyze substances that fulfill the OECD definition of PFASs and that are registered under the regulation on Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) in the EU to obtain a better data basis for PFASs and to elucidate the range of PFASs on the market in the EU. As of September 2021, at least 531 PFASs had been registered under REACH. Our hazard assessment of the PFASs registered under REACH shows that the currently available data are not sufficient to identify those PFASs that are persistent, bioaccumulative and toxic (PBT) or very persistent and very bioaccumulative (vPvB). Using some basic assumptions - which are 1) PFASs or their metabolites do not mineralize, 2) neutral hydrophobic substances bioaccumulate unless they are metabolized and 3) all chemicals exhibit baseline toxicity, and effect concentrations cannot be above effect concentrations for baseline toxicity - shows that at least 17 of the 177 PFASs with full registration are PBT substances, 14 more than currently identified. Moreover, if mobility is considered as a hazard criterion, at least 19 additional substances will need to be considered hazardous. The regulation of persistent, mobile and toxic (PMT) and very persistent and very mobile (vPvM) substances would therefore also affect PFASs. However, many of the substances that have not been identified as PBT, vPvB, PMT or vPvM are either persistent and toxic, persistent and bioaccumulative or persistent and mobile. The planned PFASs restriction will therefore be important for a more effective regulation of these substances.
PMID:36907396 | DOI:10.1016/j.scitotenv.2023.162618
Environ Sci Technol. 2022 Dec 20;56(24):17880-17889. doi: 10.1021/acs.est.2c06155. Epub 2022 Dec 6.
ABSTRACT
Persistent, mobile, and toxic (PMT) substances and very persistent and very mobile (vPvM) substances can transport over long distances from various sources, increasing the public health risk. A rapid and high-throughput screening of PMT/vPvM substances is thus warranted to the risk prevention and mitigation measures. Herein, we construct a machine learning-based screening system integrated with five models for high-throughput classification of PMT/vPvM substances. The models are constructed with 44 971 substances by conventional learning, deep learning, and ensemble learning algorithms, among which, LightGBM and XGBoost outperform other algorithms with metrics exceeding 0.900. Good model interpretability is achieved through the number of free halogen atoms (fr_halogen) and the logarithm of partition coefficient (MolLogP) as the two most critical molecular descriptors representing the persistence and mobility of substances, respectively. Our screening system exhibits a great generalization capability with area under the receiver operating characteristic curve (AUROC) above 0.951 and is successfully applied to the persistent organic pollutants (POPs), prioritized PMT/vPvM substances, and pesticides. The screening system constructed in this study can serve as an efficient and reliable tool for high-throughput risk assessment and the prioritization of managing emerging contaminants.
PMID:36475377 | DOI:10.1021/acs.est.2c06155
ACS Environ Au. 2022 Nov 16;2(6):482-509. doi: 10.1021/acsenvironau.2c00024. Epub 2022 Aug 2.
ABSTRACT
Persistent and mobile organic substances are those with the highest propensity to be widely distributed in groundwater and thereby, when emitted at low-levels, to contaminate drinking water extraction points and freshwater environments. To prevent such contamination, the European Commission is in the process of introducing new hazard classes for persistent, mobile, and toxic (PMT) and very persistent and very mobile (vPvM) substances within its key chemical regulations CLP and REACH. The assessment of persistence in these regulations will likely be based on simulated half-life, t 1/2, thresholds; the assessment of mobility will likely be based on organic carbon-water distribution coefficient, K OC, thresholds. This study reviews the use of t 1/2 and K OC to describe persistence and mobility, considering the theory, history, suitability, data limitations, estimation methods, and alternative parameters. For this purpose, t 1/2, K OC, and alternative parameters were compiled for substances registered under REACH, known transformation products, and substances detected in wastewater treatment plant effluent, surface water, bank filtrate, groundwater, raw water, and drinking water. Experimental t 1/2 values were rare and only available for 2.2% of the 14 203 unique chemicals identified. K OC data were only available for a fifth of the substances. Therefore, the usage of alternative screening parameters was investigated to predict t 1/2 and K OC values, to assist weight-of-evidence based PMT/vPvM hazard assessments. Even when considering screening parameters, for 41% of substances, PMT/vPvM assessments could not be made due to data gaps; for 23% of substances, PMT/vPvM assessments were ambiguous. Further effort is needed to close these substantial data gaps. However, when data is available, the use of t 1/2 and K OC is considered fit-for-purpose for defining PMT/vPvM thresholds. Using currently discussed threshold values, between 1.9 and 2.6% of REACH registered substances were identified as PMT/vPvM. Among the REACH registered substances detected in drinking water sources, 24-30% were PMT/vPvM substances.
PMID:36411866 | PMC:PMC9673533 | DOI:10.1021/acsenvironau.2c00024
Environ Res. 2023 Jan 1;216(Pt 4):114721. doi: 10.1016/j.envres.2022.114721. Epub 2022 Nov 4.
ABSTRACT
Wearing of vehicle parts could release many chemical additives into the environment, such as benzotriazoles (BTRs), benzothiazoles (BTHs), and p-phenylenediamines (PPDs), which are potentially toxic to wildlife and humans. This study investigated the occurrence, source, and risks of BTRs, BTHs, and PPDs in a source catchment providing water to Guangzhou, a megacity in South China, covering groundwater, surface water, and stormwater. The results showed that BTRs and BTHs were predominant in surface water and groundwater. Unexpectedly, the BTR and BTH concentrations were lower in surface water than groundwater in a third of the paired samples. For the first time, 6PPD-quinone, a toxic ozonation product of N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine (6PPD), was extensively detected in source waters. Stormwater decreased the BTR concentrations but increased the 6PPD-quinone concentrations in surface water owing to their affiliation to suspended particles. From natural to urban segments of Liuxi river, a downstream increasing trend in BTR and BTH concentrations was observed, confirming that they are indicative of urban anthropogenic activities. Strong correlations between industrial activities and BTR or BTH concentrations in surface water indicated that industrial activities were their main sources. Six compounds were prioritized as potentially persistent, mobile, and toxic (PMT) chemicals, combing our monitoring results and REACH criterion. This study improves our understanding of the environmental fates and risks of water-soluble tire-wear chemicals, which provides important information for chemical management, and indicates attention should be paid to the risk posed by 6PPD-quinone in the source water.
PMID:36343716 | DOI:10.1016/j.envres.2022.114721
Sci Total Environ. 2023 Feb 1;858(Pt 2):159821. doi: 10.1016/j.scitotenv.2022.159821. Epub 2022 Nov 2.
ABSTRACT
Shale gas exploitation is a water-intensive process, generating flowback and produced water (FPW) with complex chemical compositions. Reuse, disposal and treatment of FPW are of increasing concern, because of the potential risk of FPW contamination to the surrounding aquatic environment and drinking water sources when emitted. Among numerous organic substances present in FPW, of particular concern are those that are persistent, mobile and toxic (PMT) and very persistent and very mobile (vPvM). PMT and vPvM substances have the greatest potential to spread in groundwater and are the hardest to remediate. This study presents the outcome of a literature review to identify organic compounds that were previously detected in FPW. The 162 target compounds identified from this review were assessed to see if they can be considered PMT/vPvM substances based on their substance properties. Our results indicated that most FPW substances are "not PMT", accounting for 108 (66.7 %) compouds. In total 22 FPW substances can be considered PMT/vPvM or very likely to meet this criteria if more data were available. Examples of PMT substances in FPW include anthracene, 1,4-dioxane and 1,4-dichlorobenzene. PMT/vPvM compounds identified in FPW should be prioritized for risk management measures and monitoring in order to protect regional water resources.
PMID:36334658 | DOI:10.1016/j.scitotenv.2022.159821
Integr Environ Assess Manag. 2023 May;19(3):775-791. doi: 10.1002/ieam.4705. Epub 2022 Dec 16.
ABSTRACT
In order to protect European Union (EU) drinking water resources from chemical contamination, criteria for identifying persistent, mobile, and toxic (PMT) chemicals and very persistent and very mobile (vPvM) chemicals under the EU REACH Regulation were proposed by the German Environment Agency (Umweltbundesamt-UBA). Additionally, new hazard classes for PMT and vPvM substances in the revised EU classification, labeling, and packaging (CLP Regulation) are intended. Therefore, a reliable approach in the identification of potential drinking water resource contaminants is needed. The scientific basis of the property-based PMT/vPvM criteria, focusing on mobility, which dictates the migration of chemical drinking water sources, was evaluated, and a critical analysis of the deviation of sorption metrics from simple behavior was carried out. Based on our evaluation, a Koc may be used for nonionic substances on a screening level only, requiring a higher tier assessment. It is considered inappropriate for hydrophilic and ionizable chemicals, particularly for soils with low organic carbon contents. The nonextractable residue formation is complex and not well understood but remains significant in limiting the mobility of chemicals through soils and sediments. In order to inform the EU commission's work on the introduction of new hazard classes for PMT and vPvM substances into the European legislation, the derivation of a tiered approach is proposed, which utilizes the weight of evidence available, with adoption of appropriate higher tier models commensurate with the nature of the substance and the data available. Integr Environ Assess Manag 2023;19:775-791. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
PMID:36281826 | DOI:10.1002/ieam.4705
Environ Sci Process Impacts. 2022 Oct 19;24(10):1945-1956. doi: 10.1039/d2em00097k.
ABSTRACT
The hazards of many plastic additives on human and environmental health are well documented. However, little emphasis has been put on plastic additives that are persistent, mobile, and toxic (PMT) rather than persistent, bioaccumulative, and toxic. Due to their high mobility and stability, it is unlikely that wastewater treatment plants will effectively remove PMT plastic additives. Herein, an in silico analysis was performed to (1) assess the retention of PMT plastic additives registered for use in Canada in wastewater treatment plants; and (2) determine whether their physical-chemical properties and structural features can be used as identifiers for PMT plastic additives with particularly low retention. We identified 124 PMT plastic additives of which 52% had less than 20% removal from wastewater treatment based on predictions using the model SimpleTreat. Log Kaw, log Kow/Dow, and log Koc/Doc ranges were defined that are indicative of low retention PMT plastic additives. Furthermore, it was found that non-halogenated PMT plastic additives that contain nitrogen are most likely to be poorly retained in wastewater treatment plants. The results of this study provide screening and prioritization criteria, as well as a suspect list for PMT plastic additives.
PMID:36178267 | DOI:10.1039/d2em00097k
Environ Sci Technol. 2022 Aug 2;56(15):10857-10867. doi: 10.1021/acs.est.2c03659. Epub 2022 Jul 22.
ABSTRACT
Persistent, mobile, and toxic (PMT) and very persistent and very mobile (vPvM) substances have been recognized as a threat to both the aquatic environment and to drinking water resources. These substances are currently prioritized for regulatory action by the European Commission, whereby a proposal for the inclusion of hazard classes for PMT and vPvM substances has been put forward. Comprehensive monitoring data for many PMT/vPvM substances in drinking water sources are scarce. Herein, we analyze 34 PMT/vPvM substances in 46 surface water, groundwater, bank filtrate, and raw water samples taken throughout Germany. Results of the sampling campaign demonstrated that known PMT/vPvM substances such as 1H-benzotriazole, melamine, cyanuric acid, and 1,4-dioxane are responsible for substantial contamination in the sources of German drinking water. In addition, the results revealed the widespread presence of the emerging substances 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and diphenylguanidine (DPG). A correlation analysis showed a pronounced co-occurrence of PMT/vPvM substances associated predominantly with consumer or professional uses and also demonstrated an inhomogeneous co-occurrence for substances associated mainly with industrial use. These data were used to test the hypothesis that most PMT/vPvM substances pass bank filtration without significant concentration reduction, which is one of the main reasons for introducing PMT/vPvM as a hazard class within Europe.
PMID:35868007 | DOI:10.1021/acs.est.2c03659
Water Res. 2022 Aug 1;221:118847. doi: 10.1016/j.watres.2022.118847. Epub 2022 Jul 10.
ABSTRACT
Persistent and mobile (PM) chemicals spread quickly in the water cycle and can reach drinking water. If these chemicals are also toxic (PMT) they may pose a threat to the aquatic environment and drinking water alike, and thus measures to prevent their spread are necessary. In this study, nontarget screening and cell-based toxicity tests after a polarity-based fractionation into polar and non-polar chemicals are utilized to assess and compare the effectiveness of ozonation and filtration through activated carbon in a wastewater treatment and drinking water production plant. Especially during wastewater treatment, differences in removal efficiency were evident. While median areas of non-polar features were reduced by a factor of 270, median areas for polar chemicals were only reduced by a factor of 4. Polar features showed significantly higher areas than their non-polar counterparts in wastewater treatment plant effluent and finished drinking water, implying a protection gap for these chemicals. Toxicity tests revealed higher initial toxicities (especially oxidative stress and estrogenic activity) for the non-polar fraction, but also showed a more pronounced decrease during treatment. Generally, the toxicity of the effluent was low for both fractions. Combined, these results imply a less effective removal but also a lower toxicity of polar chemicals. The behaviour of features during advanced waste and drinking water treatment was used to classify them as either PM chemicals or mobile transformation products (M-TPs). A suspect screening of the 476 highest intensity PM chemicals and M-TPs in 57 environmental and tap water samples showed high frequencies of detection (median >80%), which indicates the wide distribution of these chemicals in the aquatic environment and thus supports the chosen classification approach and the more generally applicability of obtained insights.
PMID:35841789 | DOI:10.1016/j.watres.2022.118847
Toxicol Rep. 2020 Aug 15;7:995-1000. doi: 10.1016/j.toxrep.2020.08.014. eCollection 2020.
ABSTRACT
Quantitative structure-activity relationship (QSAR) models have been applied to predict a variety of toxicity endpoints. Their performance needs to be validated, in a variety of cases, to increase their applicability to chemical regulation. Using the data set of substances of very high concern (SVHCs), the performance of QSAR models were evaluated to predict the persistence and bioaccumulation of PBT, and the carcinogenicity and mutagenicity of CMR. BIOWIN and Toxtree showed higher sensitivity than other QSAR models - the former for persistence and bioaccumulation, the latter for carcinogenicity. In terms of mutagenicity, the sensitivities of QSAR models were underestimated, Toxtree was more accurate and specific than lazy structure-activity relationships (LAZARs) and Computer Assisted Evaluation of industrial chemical Substances According to Regulations (CAESAR). Using the weight of evidence (WoE) approach, which integrates results of individual QSAR models, enhanced the sensitivity of each toxicity endpoint. On the basis of obtained results, in particular the prediction of persistence and bioaccumulation by KOWWIN, a conservative criterion is recommended of log Kow greater than 4.5 in K-REACH, without an upper limit. This study suggests that reliable production of toxicity data by QSAR models is facilitated by a better understanding of the performance of these models.
PMID:32874922 | PMC:PMC7451722 | DOI:10.1016/j.toxrep.2020.08.014