Environmental water quality monitoring aims to provide the data required for safeguarding the environment against adverse biological effects from multiple chemical contamination arising from ...anthropogenic diffuse emissions and point sources. Here, we integrate the experience of the international EU-funded project SOLUTIONS to shift the focus of water monitoring from a few legacy chemicals to complex chemical mixtures, and to identify relevant drivers of toxic effects. Monitoring serves a range of purposes, from control of chemical and ecological status compliance to safeguarding specific water uses, such as drinking water abstraction. Various water sampling techniques, chemical target, suspect and non-target analyses as well as an array of in vitro, in vivo and in situ bioanalytical methods were advanced to improve monitoring of water contamination. Major improvements for broader applicability include tailored sampling techniques, screening and identification techniques for a broader and more diverse set of chemicals, higher detection sensitivity, standardized protocols for chemical, toxicological, and ecological assessments combined with systematic evidence evaluation techniques. No single method or combination of methods is able to meet all divergent monitoring purposes. Current monitoring approaches tend to emphasize either targeted exposure or effect detection. Here, we argue that, irrespective of the specific purpose, assessment of monitoring results would benefit substantially from obtaining and linking information on the occurrence of both chemicals and potentially adverse biological effects. In this paper, we specify the information required to: (1) identify relevant contaminants, (2) assess the impact of contamination in aquatic ecosystems, or (3) quantify cause–effect relationships between contaminants and adverse effects. Specific strategies to link chemical and bioanalytical information are outlined for each of these distinct goals. These strategies have been developed and explored using case studies in the Danube and Rhine river basins as well as for rivers of the Iberian Peninsula. Current water quality assessment suffers from biases resulting from differences in approaches and associated uncertainty analyses. While exposure approaches tend to ignore data gaps (i.e., missing contaminants), effect-based approaches penalize data gaps with increased uncertainty factors. This integrated work suggests systematic ways to deal with mixture exposures and combined effects in a more balanced way, and thus provides guidance for future tailored environmental monitoring.
Surface waters can contain a diverse range of organic pollutants, including pesticides, pharmaceuticals and industrial compounds. While bioassays have been used for water quality monitoring, there is ...limited knowledge regarding the effects of individual micropollutants and their relationship to the overall mixture effect in water samples. In this study, a battery of in vitro bioassays based on human and fish cell lines and whole organism assays using bacteria, algae, daphnids and fish embryos was assembled for use in water quality monitoring. The selection of bioassays was guided by the principles of adverse outcome pathways in order to cover relevant steps in toxicity pathways known to be triggered by environmental water samples. The effects of 34 water pollutants, which were selected based on hazard quotients, available environmental quality standards and mode of action information, were fingerprinted in the bioassay test battery. There was a relatively good agreement between the experimental results and available literature effect data. The majority of the chemicals were active in the assays indicative of apical effects, while fewer chemicals had a response in the specific reporter gene assays, but these effects were typically triggered at lower concentrations. The single chemical effect data were used to improve published mixture toxicity modeling of water samples from the Danube River. While there was a slight increase in the fraction of the bioanalytical equivalents explained for the Danube River samples, for some endpoints less than 1% of the observed effect could be explained by the studied chemicals. The new mixture models essentially confirmed previous findings from many studies monitoring water quality using both chemical analysis and bioanalytical tools. In short, our results indicate that many more chemicals contribute to the biological effect than those that are typically quantified by chemical monitoring programs or those regulated by environmental quality standards. This study not only demonstrates the utility of fingerprinting single chemicals for an improved understanding of the biological effect of pollutants, but also highlights the need to apply bioassays for water quality monitoring in order to prevent underestimation of the overall biological effect.
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•Bioassay battery for water quality assessment assembled and applied to 34 chemicals.•Data mining exercise highlighted lack of available effect data for mixture modeling.•All chemicals active in at least one assay, with bisphenol A active in 70% of assays.•Diversity of possible modes of action advises complementary use of apical endpoints.•Single chemical contribution to observed effect shown by mixture toxicity modeling.
The present monitoring and assessment of the chemical status of water bodies fail to characterize the likelihood that complex mixtures of chemicals affect water quality. The European Collaborative ...Project SOLUTIONS suggests that this likelihood can be estimated with effect-based methods (EBMs) complemented by chemical screening and/or impact modeling. These methods should be used to identify the causes of impacted water quality and to develop programs of measures to improve water quality. Along this line of reasoning, effect-based methods are recommended for Water Framework Directive (WFD) monitoring to cover the major modes of action in the universe of environmentally relevant chemicals so as to evaluate improvements of water quality upon implementing the measures. To this end, a minimum battery of bioassays has been recommended including short-term toxicity to algae,
Daphnia
and fish embryos complemented with in vitro and short-term in vivo tests on mode-of-action specific effects as proxies for long-term toxicity. The likelihood of adverse impacts can be established with effect-based trigger values, which differentiate good from poor water quality in close alignment with Environmental Quality Standards for individual chemicals, while taking into account mixture toxicity. The use of EBMs is suggested in the WFD as one avenue to establish the likelihood of adverse effects due to chemical pollution in European water systems. The present paper has been written as one component of a series of policy briefs to support decisions on water quality monitoring and management under the WFD.
To verify whether dyes emitted within the discharge of a dye processing plant were contributing to the mutagenicity repeatedly found in the Cristais River, São Paulo, Brazil, we chemically ...characterized the following mutagenic samples: the treated industrial effluent, raw and treated water, and the sludge produced by a Drinking Water Treatment Plant (DWTP) located ∼6
km from the industrial discharge. Considering that 20% of the dyes used for coloring activities might be lost to wastewaters and knowing that several dyes have mutagenic activity, we decided to analyze the samples for the presence of dyes. Thin layer chromatographic analysis indicated the presence of three prevalent dyes in all samples, except for the drinking water. This combination of dyes corresponded to a commercial product used by the industry, and it tested positive in the Salmonella assay. The structures of the dye components were determined using proton magnetic resonance and mass spectrometric (MS) methods, and the dyes were tested for mutagenicity. The blue component was identified as the C.I. Disperse Blue 373, the violet as C.I. Disperse Violet 93, and the orange as C.I. Disperse Orange 37. The dyes showed mutagenic responses of 6300, 4600, and 280 revertants/μg for YG1041 with S9 respectively. A bioassay-directed fractionation/chemical analysis showed that the C.I. Disperse Blue 373 contributed 55% of the mutagenic activity of the DWTP sludge. We showed that these dyes contributed to the mutagenic activity found in the Cristais River environmental samples analyzed and are indirectly affecting the quality of the related drinking water. Therefore, we believe that this type of discharge should be more thoroughly characterized chemically and toxicologically. Additionally, human and ecological risks associated with the release of dye processing plant effluents should be more fully investigated, especially where the resultant water is taken for human consumption.
Aquatic environments are often contaminated with complex mixtures of chemicals that may pose a risk to ecosystems and human health. This contamination cannot be addressed with target analysis alone ...but tools are required to reduce this complexity and identify those chemicals that might cause adverse effects. Effect-directed analysis (EDA) is designed to meet this challenge and faces increasing interest in water and sediment quality monitoring. Thus, the present paper summarizes current experience with the EDA approach and the tools required, and provides practical advice on their application. The paper highlights the need for proper problem formulation and gives general advice for study design. As the EDA approach is directed by toxicity, basic principles for the selection of bioassays are given as well as a comprehensive compilation of appropriate assays, including their strengths and weaknesses. A specific focus is given to strategies for sampling, extraction and bioassay dosing since they strongly impact prioritization of toxicants in EDA. Reduction of sample complexity mainly relies on fractionation procedures, which are discussed in this paper, including quality assurance and quality control. Automated combinations of fractionation, biotesting and chemical analysis using so-called hyphenated tools can enhance the throughput and might reduce the risk of artifacts in laboratory work. The key to determining the chemical structures causing effects is analytical toxicant identification. The latest approaches, tools, software and databases for target-, suspect and non-target screening as well as unknown identification are discussed together with analytical and toxicological confirmation approaches. A better understanding of optimal use and combination of EDA tools will help to design efficient and successful toxicant identification studies in the context of quality monitoring in multiply stressed environments.
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•Effect-directed analysis is a powerful tool to support monitoring.•Multiple bioassays on specific and reactive toxicity direct toxicant identification•Combination of extraction and bioassay dosing is key for toxicant identification•Promising tools for LC–MS based toxicant identification are now available
Traditional textile dyeing processes usually require large quantities of water and energy and generate wastewater that can be harmful to the environment. Dyeing in supercritical carbon dioxide ...(sc‐CO2) media is promising in textile coloration due especially to it providing a waterless process and eliminating the need for an energy intensive drying step. The natural anthraquinone emodin showed promising results for dyeing different fibres through sc‐CO2 process. However, emodin is mutagenic. The aim of this study was to develop non‐mutagenic derivatives of emodin that can be applied to textiles using sc‐CO2. Emodin structure was modified incorporating acryloyl groups, which are considered suitable for decreasing potential for DNA intercalation, and thus mutagenicity. The presence of acryloyl groups would also enable atmospheric plasma induced bonding with fibres. Molecular modelling studies showed that emodin derivatives became less planar with increasing number of attached acryloyl groups, making intercalation unlikely. The derivatives produced were tested to assess mutagenicity in vitro (Salmonella/microsome assay, TA1537, 10% S9) and in vivo (micronucleus test in hemocytes of aquatic crustacean). We found that emodin can be derivatised using acryloyl chlorides to give mono‐ and di‐acrylate esters suitable for dyeing polyester fibres in sc‐CO2. However, the new dyes presented mutagenicity for both in vitro and in vivo. Although the derivatives provided greenish‐yellow alternatives to emodin for dyeing synthetic fibres, they do not appear to be viable alternatives from the point of view of preserving human and environmental health. Plasma bonding studies are underway.
Organophosphate esters (OPEs) are substances globally used as flame retardants and plasticizers that have been detected in all environmental compartments. This study aimed to evaluate the occurrence ...and sources of ten OPEs in the Piracicaba River Basin (Brazil). Twelve sampling sites were selected in five rivers with different pollution sources; six sampling campaigns were performed encompassing dry and wet seasons. ΣOPEs ranged from 0.12 to 6.2 μg L
−1
; the levels in urban areas were higher than in rural and non-urban areas, but no overall tendency concerning the seasonal effect on OPEs concentrations was observed. Tris(2-butoxyethyl) phosphate (TBOEP), tris(2-chloroisopropyl) phosphate (TCIPP), and tris(1,3-dichloroisopropyl) phosphate (TDCIPP) were the most abundant and frequently detected compounds. Nine OPEs were detected at higher concentrations in a site affected by effluents from textile industries. An acute toxicity test using
Daphnia similis
was performed for tris(2-ethylhexyl) phosphate (TEHP) for the calculation of a preliminary predicted no effect concentration (PNEC). The risk quotient (RQ) approach was applied and risk to aquatic environment related to TEHP levels was observed in areas adjacent to textile industries, but more toxicity studies are required for the determination of a more reliable PNEC.
Sperm quality is defined as the sperm cell ability to successfully fertilize eggs and allow normal embryo development. Few studies explore sperm quality using aquatic invertebrates. Parhyale ...hawaiensis is a marine amphipod with a circumtropical distribution and considered a model for evolution, development, and ecotoxicological studies. We aimed to develop a methodology to collect sperm cells of P. hawaiensis and evaluate their viability and DNA damage (comet assay). We directly exposed the sperm cells to different mutagenic agents to optimize/develop the protocols. Then, as a proof of concept, we exposed the males to mutagenic compounds (EMS, benzoapyrene (BaP), azo and anthraquinone dyes) at non-lethal concentrations verified by the proposed viability test and analyzed their sperm cells for DNA damage (comet assay). Organisms exposed to EMS presented a clear concentration response in the DNA damage response. We also showed that BaP was able to induce a statistically significant increase in DNA damage of the sperm cells. For the two dyes, although DNA damage increased, statistically differences were not observed. We believe we successfully developed a test to detect genotoxicity of chemicals in sperm cells using an invertebrate model. The protocol for sperm cell viability needs to be further explored with different chemicals to verify its utility as a toxicity endpoint. The developed genotoxicity test has the advantages to employ organisms that are easily cultivated in reduced space, use simple laboratory resources and reduced amount of material and reagents. Positive responses with this model could be used to disclose new germ cell mutagen candidates which could be further confirmed in vertebrates' systems.
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•Methodology to evaluate sperm integrity was developed for P. hawaiensis.•Exposure can be performed directly in sperm cells or living organisms.•Sperm cells are more sensitive than hemocytes to DNA damage.•Benzoapyrene and ethyl methanesulfonate increased DNA damage in sperm cells.
Bioassays have been used to complement the chemical characterization of aquatic mutagenicity, but the tests sometimes are done only with water liquid phase (LP). Particle-bound mutagens are important ...because they can be ingested by filtering organisms. Our objective was to evaluate the mutagenicity of organic extracts of the LP and the water suspended particulate matter (SPM) from 13 sites along Danube River with the Salmonella/microsome microsuspension assay using TA98, YG1041, TA1538, and YG5185 strains. A high incidence of mutagenicity was detected, 84% for LP and 92% for SPM samples. The contribution of SPM to the mutagenicity was relatively small when compared with LP however, for five sites SPM was responsible for the whole mutagenicity, highlighting the importance of analyzing SPM when assessing water mutagenicity. YG1041 was the most sensitive strain and should be considered in future water mutagenicity monitoring programs, but it will depend on the main pollution sources.
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