Showing papers in "Environmental Sciences Europe in 2019"

Future water quality monitoring: improving the balance between exposure and toxicity assessments of real-world pollutant mixtures

Abstract: 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.

Effect-based methods are key. The European Collaborative Project SOLUTIONS recommends integrating effect-based methods for diagnosis and monitoring of water quality

Abstract: 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.

How did the US EPA and IARC reach diametrically opposed conclusions on the genotoxicity of glyphosate-based herbicides?

Abstract: The US EPA considers glyphosate as “not likely to be carcinogenic to humans.” The International Agency for Research on Cancer (IARC) has classified glyphosate as “probably carcinogenic to humans (Group 2A).” EPA asserts that there is no convincing evidence that “glyphosate induces mutations in vivo via the oral route.” IARC concludes there is “strong evidence” that exposure to glyphosate is genotoxic through at least two mechanisms known to be associated with human carcinogens (DNA damage, oxidative stress). Why and how did EPA and IARC reach such different conclusions? A total of 52 genotoxicity assays done by registrants were cited by the EPA in its 2016 evaluation of technical glyphosate, and another 52 assays appeared in the public literature. Of these, one regulatory assay (2%) and 35 published assays (67%) reported positive evidence of a genotoxic response. In the case of formulated, glyphosate-based herbicides (GBHs), 43 regulatory assays were cited by EPA, plus 65 assays published in peer-reviewed journals. Of these, none of the regulatory, and 49 published assays (75%) reported evidence of a genotoxic response following exposure to a GBH. IARC considered a total of 118 genotoxicity assays in six core tables on glyphosate technical, GBHs, and aminomethylphosphonic acid (AMPA), glyphosate’s primary metabolite. EPA’s analysis encompassed 51 of these 118 assays (43%). In addition, IARC analyzed another 81 assays exploring other possible genotoxic mechanisms (mostly related to sex hormones and oxidative stress), of which 62 (77%) reported positive results. IARC placed considerable weight on three positive GBH studies in exposed human populations, whereas EPA placed little or no weight on them. EPA and IARC reached diametrically opposed conclusions on glyphosate genotoxicity for three primary reasons: (1) in the core tables compiled by EPA and IARC, the EPA relied mostly on registrant-commissioned, unpublished regulatory studies, 99% of which were negative, while IARC relied mostly on peer-reviewed studies of which 70% were positive (83 of 118); (2) EPA’s evaluation was largely based on data from studies on technical glyphosate, whereas IARC’s review placed heavy weight on the results of formulated GBH and AMPA assays; (3) EPA’s evaluation was focused on typical, general population dietary exposures assuming legal, food-crop uses, and did not take into account, nor address generally higher occupational exposures and risks. IARC’s assessment encompassed data from typical dietary, occupational, and elevated exposure scenarios. More research is needed on real-world exposures to the chemicals within formulated GBHs and the biological fate and consequences of such exposures.

Ensuring sustainability in plastics use in Africa: consumption, waste generation, and projections

Abstract: Currently, plastic is at the top of the international agenda for waste management. Recent meetings of the Conferences of the Parties to the Basel and the Stockholm Conventions have expressed concerns over the impact of plastic waste, marine plastic litter, and microplastics, and emphasised the importance of reducing consumption and ensuring the environmentally sound management of waste plastics. This study presents the first continental historical analysis of mass importation and consumption of different polymers and plastics (primary and secondary forms, respectively) in Africa and the associated pollution potential. We identified, collated and synthesised dispersed international trade data on the importation of polymers and plastics into several African countries. The 33 African countries (total population of 856,671,366) with available data for more than 10 years imported approximately 86.14 Mt of polymers in primary form and 31.5 Mt of plastic products between 1990 and 2017. Extrapolating to the continental level (African population of 1.216 billion in 54 countries), about 172 Mt of polymers and plastics valued at $285 billion were imported between 1990 and 2017. Considering also the components of products, an estimated 230 Mt of plastics entered Africa during that time period, with the largest share going to Egypt (43 Mt, 18.7%), Nigeria (39 Mt, 17.0%), South Africa (27 Mt, 11.7%), Algeria (26 Mt, 11.3%), Morocco (22 Mt, 9.6%), and Tunisia (16 Mt, 7.0%). Additionally, primary plastic production in 8 African countries contributed 15 Mt during 2009–2015. The assessment showed that environmentally sound end-of-life management of waste plastics by recycling and energy recovery is in its infancy in Africa, but recycling activities and thermal recovery have started in a few countries. Globally, the perception is that production and consumption of plastics can only increase in the future. Solutions are needed to tackle this global challenge. Certain policies and plastic bag bans could help reduce plastic consumption in the near future, as demonstrated by Rwanda. Furthermore, there is a need for innovative solutions such as the introduction of biodegradable polymers and other alternatives, especially for packaging.

Commentary on the draft revised guideline on the environmental risk assessment of medicinal products for human use

Abstract: Applicants for marketing authorisation for human medicinal products in the European Union must submit an environmental risk assessment which is assessed by assessors from the national competent authorities. The EMA guideline on the environmental risk assessment of medicinal products for human use came into effect on 1 December 2006. After 12 years’ experience with the guideline, the EMA has released for public consultation a draft revision of the guideline. The revision proposes significant substantive and structural changes to the guideline. The major changes proposed in the revision are outlined together with the rationale for the changes and the expected impact on stakeholders.

High resolution mass spectrometry-based non-target screening can support regulatory environmental monitoring and chemicals management

Abstract: Non-target screening (NTS) including suspect screening with high resolution mass spectrometry has already shown its feasibility in detecting and identifying emerging contaminants, which subsequently triggered exposure mitigating measures. NTS has a large potential for tasks such as effective evaluation of regulations for safe marketing of substances and products, prioritization of substances for monitoring programmes and assessment of environmental quality. To achieve this, a further development of NTS methodology is required, including: (i) harmonized protocols and quality requirements, (ii) infrastructures for efficient data management, data evaluation and data sharing and (iii) sufficient resources and appropriately trained personnel in the research and regulatory communities in Europe. Recommendations for achieving these three requirements are outlined in the following discussion paper. In particular, in order to facilitate compound identification it is recommended that the relevant information for interpretation of mass spectra, as well as about the compounds usage and production tonnages, should be made accessible to the scientific community (via open-access databases). For many purposes, NTS should be implemented in combination with effect-based methods to focus on toxic chemicals.

Future pesticide risk assessment: narrowing the gap between intention and reality

Abstract: Agrochemicals, such as pesticides and fertilizers, have facilitated an unprecedented intensification of agriculture [1, 2]. However, the desired yield gains come at the cost of unwanted side effects on the environment. Pesticides have been demonstrated to contribute to the decline of non-target organisms, such as bees, birds and aquatic biodiversity [3,4,5], fueling the global biodiversity crisis. This runs contrary to global efforts to protect biodiversity and, in particular, also to the aims of the European Union’s (EU) pesticide regulation [6]. Consistent exceedances of regulatory thresholds [7] and revisions of authorizations of pesticides, such as of neonicotinoid insecticides in the EU by the Standing Committee on plants, animals, food and feed (PAFF Committee), also attest to deficiencies in regulatory pesticide risk assessment and management.

Effects of cyanobacterial toxins on the human gastrointestinal tract and the mucosal innate immune system

Abstract: Cyanobacterial blooms occur with increasing frequency in freshwater ecosystems, posing a hazard to human and environmental health. Exposure of human to cyanobacterial metabolites occurs mostly via accidental ingestion through contaminated drinking water or during recreational activities and, most frequently, results in gastrointestinal symptoms. Despite the clinical manifestation, cyanobacterial metabolites are rather investigated for their toxicity towards specific organs or tissues, especially hepato-, nephro-, and neurotoxicity, than for effects on the gastrointestinal tract and the associated lymphoid tissue. The aim of this review was to systematically summarize available literature on the effects on the gastrointestinal tract and the mucosal innate immune system and compile the data from both, in vitro and in vivo studies, focusing on human health-relevant models. Our systematic literature review revealed significant data gaps in the understanding on metabolites breaching the gastrointestinal barrier and the role of the immune system in the establishment of clinical symptoms. Microcystins and cylindrospermopsin were linked to gastrointestinal symptoms, immune system effects, or both. Furthermore, cyanobacterial bloom lipopolysaccharides, other less studied metabolites and their mixtures have been also implicated to have a role in gastrointestinal inflammation. The collected data indicate the need for a reassessment of potential enterotoxicity of microcystins and cylindrospermopsin. In addition, the carcinogenic potential of cyanotoxins, especially microcystins, has to be clarified, as an increasing amount of epidemiological studies show correlations between cyanobacterial blooms and gastrointestinal cancer incidence. Furthermore, other, often highly abundant bioactive metabolites such as aeruginosins, have to be toxicologically evaluated at distinct levels also accounting for (sub-)chronic exposure to low concentrations and in combination with naturally co-occurring metabolites, which can be expected in drinking water supplies.

High-resolution mass spectrometry to complement monitoring and track emerging chemicals and pollution trends in European water resources

Abstract: Currently, chemical monitoring based on priority substances fails to consider the majority of known environmental micropollutants not to mention the unexpected and unknown chemicals that may contribute to the toxic risk of complex mixtures present in the environment. Complementing component- and effect-based monitoring with wide-scope target, suspect, and non-target screening (NTS) based on high-resolution mass spectrometry (HRMS) data is recommended to support environmental impact and risk assessment. This will allow for detection of newly emerging compounds and transformation products, retrospective monitoring efforts, and the identification of possible drivers of toxicity by correlation with effects or modelling of expected effects for future and abatement scenarios. HRMS is becoming increasingly available in many laboratories. Thus, the time is right to establish and harmonize screening methods, train staff, and record HRMS data for samples from regular monitoring events and surveys. This will strongly enhance the value of chemical monitoring data for evaluating complex chemical pollution problems, at limited additional costs. Collaboration and data exchange on a European-to-global scale is essential to maximize the benefit of chemical screening. Freely accessible data platforms, inter-laboratory trials, and the involvement of international partners and networks are recommended.

Costs and benefits of agricultural ammonia emission abatement options for compliance with European air quality regulations

Abstract: In Europe, ammonia (NH3) emissions strongly contribute to fine particulate matter (PM2.5) pollution and associated premature human mortality. The National Emission Ceilings Directive 2016/2284/EU has set an obligation for all European Union countries to reduce the NH3 emissions by 6%, relative to 2005, by 2020. This study aims to assess the costs and benefits of four NH3 emission abatement options for the compliance of the agricultural sector with the commitments of the European air quality regulatory framework. A regional atmospheric model (WRF/Chem) was used to assess the effects of regulating NH3 emissions reductions on PM2.5 concentrations over Europe. Non-market valuation techniques (value of statistical life) were used to monetize the associated health outcomes. We calculated that 16 out of the 28 EU member states exceeded their 2020 NH3 emission ceilings in 2016. The highest exceedances from the 2020 emission commitment level occurred in Latvia (15%), Germany (12%) and the UK (12%). Simulation of the required NH3 emission reduction by WRF/Chem showed that relatively large reductions in PM2.5 concentrations occur over central-western Europe and the UK. The largest health benefits (> 5% reduction in premature mortality) were found for Scandinavia. The economic benefit from avoided premature deaths over Europe amounts to 14,837 M€/year. The costs of four NH3 emission abatement options, where each would fully achieve the required emission reduction, range from 80 M€/year for low nitrogen feed to 3738 M€/year for low-emission animal housing, with covered manure storage (236 M€/year) and urea fertilizer application (253 M€/year), in between. Our analysis indicates that the costs of compliance by the agricultural sector with the commitments of the European air quality regulations are much lower than the economic benefit. Thus, much more ambitious reduction commitments for NH3 emissions could be applied by the EU-28. The monetization of the health benefits of NH3 emission abatement policies and the assessment of the implementation costs can help policy-makers devise effective air pollution control programmes.

Assessing the neutralisation, wet deposition and source contributions of the precipitation chemistry over Europe during 2000–2017

Abstract: The chemical composition of precipitation was assessed in 27 European countries from 2000 to 2017, offering a general point of view on the rainwater chemistry in Europe, contributing to a larger understanding of air pollution and atmospheric chemistry. The volume-weighted mean concentrations (VWM) were calculated, showing the relative dominance of SO 4 2− and Cl−, explaining the acidic and slightly acidic pH values that ranged from 4.19 to 5.82 over Europe. The VWM concentrations of ionic species measured in rainwater usually followed the SO 4 2 > Cl− > Na+ > NH4+ > NO3− > H+ > Ca2+ > Mg2+ > K+ > HCO3− downward order, with small exceptions, depending on the industrial activity or legal framework of a particular area. Fractional acidity showed that ~ 69% of the inorganic acidity in precipitation is neutralised, whilst neutralisation factors showed that Na+ and NH4+ contributed the most to the neutralising process. The relationship between acidic and neutralising compounds was further examined by calculating the ionic ratios. Wet deposition rates showed the dominance of acidic compounds over neutralising ones, reflecting the climatic influences and the local and regional economic characteristics of different regions from Europe. Origins of major ions in rainwater were examined using the sea salt and non-sea salt fractions, crustal and marine enrichment factors, correlation analysis and the Principal Component Analysis, showing the significant influence of anthropogenic sources (industry, agriculture, traffic). Natural sources (maritime, terrestrial) also play a major role in influencing the precipitation chemistry of the European continent. The main conclusion of this study regarding the precipitation chemistry of the European continent during the studied period is represented by the relative homogenous distribution of the analysed chemical species, which is most likely due to the unitary economic development and to the implementation of common European policies in the field of environmental protection. Since the pH is still acidic due to the anthropogenic emissions, more attention should be given to the implementation of environmental legislation, especially in non-European Union countries or in countries that joined recently.

Impact of silver nanoparticles (AgNP) on soil microbial community depending on functionalization, concentration, exposure time, and soil texture

Abstract: Increasing exposure to engineered inorganic nanoparticles takes actually place in both terrestric and aquatic ecosystems worldwide. Although we already know harmful effects of AgNP on the soil bacterial community, information about the impact of the factors functionalization, concentration, exposure time, and soil texture on the AgNP effect expression are still rare. Hence, in this study, three soils of different grain size were exposed for up to 90 days to bare and functionalized AgNP in concentrations ranging from 0.01 to 1.00 mg/kg soil dry weight. Effects on soil microbial community were quantified by various biological parameters, including 16S rRNA gene, photometric, and fluorescence analyses. Multivariate data analysis revealed significant effects of AgNP exposure for all factors and factor combinations investigated. Analysis of individual factors (silver species, concentration, exposure time, soil texture) in the unifactorial ANOVA explained the largest part of the variance compared to the error variance. In depth analysis of factor combinations revealed even better explanation of variance. For the biological parameters assessed in this study, the matching of soil texture and silver species, and the matching of soil texture and exposure time were the two most relevant factor combinations. The factor AgNP concentration contributed to a lower extent to the effect expression compared to silver species, exposure time and physico–chemical composition of soil. The factors functionalization, concentration, exposure time, and soil texture significantly impacted the effect expression of AgNP on the soil microbial community. Especially long-term exposure scenarios are strongly needed for the reliable environmental impact assessment of AgNP exposure in various soil types.

A comparison of log Kow (n-octanol–water partition coefficient) values for non-ionic, anionic, cationic and amphoteric surfactants determined using predictions and experimental methods

Abstract: Surfactants are widely used across the globe both in industrial and consumer products. The n-octanol/water partition ratio or coefficient (log Kow) and n-octanol/water distribution coefficient (log D) are key parameters in environmental risk assessment of chemicals as they are often used to estimate the environmental fate and bioavailability and thus exposure and toxicity of a compound. Determining log Kow data for surfactants is a technical challenge due to their amphiphilic properties. Currently several existing experimental OECD methods (e.g. slow-stirring, HPLC, solubility ratio) and QSPR models are available for log Kow/D measurement or prediction. However, there are concerns that these methods have not been fully validated for surfactants and may not be applicable due to the specific phase behaviour of surfactants. The current methods were evaluated for the four surfactant classes (non-ionic, anionic, cationic and amphoteric). The solubility ratio approach, based on comparative n-octanol and water solubility measurements, did not generate robust or accurate data. The HPLC method generates consistently higher log Kow values than the slow-stirring method for non-ionics, but this positive bias could be removed using reference surfactants with log Kow values determined using the slow-stirring method. The slow-stirring method is the most widely applicable experimental method for generating log Kow/D data for all the surface-active test compounds. Generally, QSPR-predicted log Kow/D values do not correlate well with experimental values, apart for the group of non-ionic surfactants. Relatively, large differences in predicted log Kow/D values were observed when comparing various QSPR models, which were most noticeable for the ionised surfactants. The slow-stirring method is the most widely applicable experimental method for generating log Kow/D data for all the four surfactant classes. A weight of evidence approach is considered appropriate for non-ionic surfactants using experimental and model predications. However, it is more difficult to apply this approach to ionisable surfactants. Recommendations are made for the preferred existing QSPR predictive methods for determination of log Kow/D values for the surfactant classes. Investigation of newer alternative experimental log Kow methods as well as more biologically relevant and methodologically defensible alternative methods for describing partitioning of surfactants are recommended.

Hypo- or hyperactivity of zebrafish embryos provoked by neuroactive substances: a review on how experimental parameters impact the predictability of behavior changes

Abstract: Tests with zebrafish embryos have gained wide acceptance as an alternative test model for drug development and toxicity testing. In particular, the behavioral response of the zebrafish embryo is currently seen as a useful endpoint to diagnose neuroactive substances. Consequently, several behavioral test methods have been developed addressing various behavioral endpoints such as spontaneous tail coiling (STC), photomotor response (PMR), locomotor response (LMR) and alternating light/dark-induced locomotor response (LMR-L/D). Although these methods are distinct in their application, most of their protocols differ quite strongly in the use of experimental parameters and this is usually driven by different research questions. However, if a single mode of action is to be diagnosed, then varying experimental parameters may cause incoherent behavioral responses (hypo- or hyperactivity) of zebrafish during toxicity assessment. This could lead to inconclusiveness of behavioral test results for use within a prospective and diagnostic risk assessment framework. To investigate the influence of these parameters, we conducted a review of existing behavioral assays to address the following two questions: (1) To what extent do varying experimental parameters influence observed effects in published behavioral test methods? (2) Is the observed behavior change (hypo- or hyperactivity) of zebrafish embryos consistent with the expected mode of action of a chemical? We compiled a set of 18 substances which are anticipated to be neuroactive. We found that behavioral changes are not only affected by chemicals but also variation in the use of experimental parameters across studies seems to have a high impact on the outcome and thus comparability between studies. Four parameters, i.e., exposure concentration, exposure duration, endpoint parameter and developmental stage were the most influential parameters. Varying combinations of these parameters caused a non-reproducible outcome for the hyperactivity expected for the organophosphates; chlorpyrifos and diazinon. We highlighted that the STC test shows a higher capacity to predict the hyperactivity of organophosphates, while PMR and LMR-L/D were more suitable to predict the hypoactivity expected for anticonvulsants. We provide a list of recommendations which, when implemented, may help to exclude the risk of bias due to experimental parameters if similar goals are desired.

Occurrence and distribution of antibiotic resistance genes in the water and sediments of Qingcaosha Reservoir, Shanghai, China

Abstract: Qingcaosha Reservoir is China’s largest river impoundment and an important drinking water resource for Shanghai city. Although antibiotics contamination in the reservoir has been reported, little is known about the presence of antibiotic resistance genes (ARGs). In this study, the occurrence and distribution of 12 ARGs and the class 1 integron gene (intI-1) in water and sediments collected from the reservoir were investigated for 1 year. The 12 ARGs were detected in both water and sediment samples, and no significant temporal or spatial variations were observed. Sulfonamide resistance genes were predominant in the reservoir with a detection frequency of 100%. Statistical analysis indicated a positive correlation in relative abundance between some ARGs such as sul1, sul2, and intI-1. Most ARGs were negatively correlated with total nitrogen and positively correlated with chemical oxygen demand and chlorophyll-a. In general, ARGs were found to be prevalent in Qingcaosha Reservoir, among which sulfonamide resistance genes were the most dominant and tetB was the least. intI-1 may facilitate the proliferation and propagation of some ARGs, especially sul1 and sul2. The abundance of ARGs was well correlated with aquatic environmental factors in water, providing potential clues for the control of ARG contamination.

Developments in society and implications for emerging pollutants in the aquatic environment

Abstract: Pollutant emissions in river basins may be subject to change. How can we succeed in predicting future pollutant emissions and risks? The approach presented here is based on the hypothesis that the existing scenarios on developments in society may provide useful indications on future pollutants. To begin with, the results of four societal scenario-based analyses showed that some developments are directly connected to consumption and the emission of specific substances. Second, it appeared that the effects of other development scenarios are more complex, such as those associated with climate change. Quantitative statements with regard to the implications of such scenarios on future pollutants can be particularly difficult. A third important group of changes are technological developments. Frequently observed changes in this respect are substitutions of problematic substances by substances with a similar structure. When the pollutant consequences of future development scenarios are taken together it will be possible to explore political, societal, or technical mitigation efforts which can be undertaken now or in the near future to counteract the effects of developments that are considered as extremely hazardous for man and the environment. Thereby, a careful monitoring of developments in society can help to develop appropriate strategies which should include preemptive emission and impact reduction efforts. Finally, we developed recommendations how to manage future emerging pollutants in river basins.

Improved component-based methods for mixture risk assessment are key to characterize complex chemical pollution in surface waters

Abstract: The present monitoring and assessment of water quality problems fails to characterize the likelihood that complex mixtures of chemicals affect water quality. The European collaborative project SOLUTIONS suggests that this likelihood can be estimated, amongst other methods, with improved component-based methods (CBMs). The use of CBMs is a well-established practice in the WFD, as one of the lines of evidence to evaluate chemical pollution on a per-chemical basis. However, this is currently limited to a pre-selection of 45 and approximately 300 monitored substances (priority substances and river basin-specific pollutants, respectively), of which only a few actually co-occur in relevant concentrations in real-world mixtures. Advanced CBM practices are therefore needed that consider a broader, realistic spectrum of chemicals and thereby improve the assessment of mixture impacts, diagnose the causes of observed impacts and provide more useful water management information. Various CBMs are described and illustrated, often representing improvements of well-established methods. Given the goals of the WFD and expanding on current guidance for risk assessment, these improved CBMs can be applied to predicted or monitored concentrations of chemical pollutants to provide information for management planning. As shown in various examples, the outcomes of the improved CBMs allow for the evaluation of the current likelihood of impacts, of alternative abatement scenarios as well as the expected consequences of future pollution scenarios. The outputs of the improved CBMs are useful to underpin programmes of measures to protect and improve water quality. The combination of CBMs with effect-based methods (EBMs) might be especially powerful to identify as yet underinvestigated emerging pollutants and their importance in a mixture toxicity context. The present paper has been designed as one in a series of policy briefs to support decisions on water quality protection, monitoring, assessment and management under the European Water Framework Directive (WFD).

Mixture risks threaten water quality: the European Collaborative Project SOLUTIONS recommends changes to the WFD and better coordination across all pieces of European chemicals legislation to improve protection from exposure of the aquatic environment to multiple pollutants

Abstract: Evidence is mounting that chemicals can produce joint toxicity even when combined at levels that singly do not pose risks. Environmental Quality Standards (EQS) defined for single pollutants under the Water Framework Directive (WFD) do not protect from mixture risks, nor do they enable prioritization of management options. Despite some provisions for mixtures of specific groups of chemicals, the WFD is not fit for purpose for protecting against or managing the effects of coincidental mixtures of water-borne pollutants. The conceptual tools for conducting mixture risk assessment are available and ready for use in regulatory and risk assessment practice. Extension towards impact assessment using cumulative toxic unit and mixture toxic pressure analysis based on chemical monitoring data or modelling has been suggested by the SOLUTIONS project. Problems exist in the availability of the data necessary for mixture risk assessments. Mixture risk assessments cannot be conducted without essential input data about exposures to chemicals and their toxicity. If data are missing, mixture risk assessments will be biassed towards underestimating risks. The WFD itself is not intended to provide toxicity data. Data gaps can only be closed if proper feedback links between the WFD and other EU regulations for industrial chemicals (REACH), pesticides (PPPR), biocides (BPR) and pharmaceuticals are implemented. Changes of the WFD alone cannot meet these requirements. Effect-based monitoring programmes developed by SOLUTIONS should be implemented as they can capture the toxicity of complex mixtures and provide leads for new candidate chemicals that require attention in mixture risk assessment. Efforts of modelling pollutant levels and their anticipated mixture effects in surface water can also generate such leads. New pollutant prioritization schemes conceived by SOLUTIONS, applied in the context of site prioritization, will help to focus mixture risk assessments on those chemicals and sites that make substantial contributions to mixture risks.

Assessment of the impact of abattoir effluent on the quality of groundwater in a residential area of Omu-Aran, Nigeria

Abstract: Water pollution from abattoir effluents may create substantial environmental and public health hazards. Available literature is scanty on the quality of groundwater located near abattoirs in tropical developing countries like Nigeria. This study, therefore, accessed the impact of abattoir activities on the quality of groundwater in Omu-Aran Nigeria. A total of eighteen water samples were taken from five privately own wells and one control well located at varying distances and elevations to the abattoir. The physicochemical characteristics of the water were determined using the standard methods. Data were analyzed using descriptive statistics and ANOVA. The mean values of parameters in the water samples collected from the studied wells ranged from 5.80 ± 0.20 to 7.23 ± 0.55 mg/L, 12.0 ± 1.0 to 26.0 ± 2.0 mg/L, 0.06 ± 0.02 to 0.16 ± 0.02 mg/L and 208.0 ± 24.25 to 254.67 ± 12.22 cfu/mL for dissolved oxygen, biological oxygen demand, lead and total coliforms, respectively. There was a significant difference in the quality of water from the studied and control wells in the parameters except that of total coliform. The quality of the groundwater improved with increasing distance from the abattoir. Findings revealed that abattoirs have the potential to impact the quality of groundwater. Therefore, careful consideration is required when choosing a location for siting new abattoirs. For existing ones, particularly those close to residential areas, effective pollution control measures should be put in place to protect groundwater.

Pesticide contamination and associated risk factors at public playgrounds near intensively managed apple and wine orchards

Abstract: Pesticide levels are generally monitored within agricultural areas, but are commonly not assessed at public places. To assess possible contamination of non-target areas, 71 public playgrounds located next to intensively managed apple and wine orchards were selected in four valleys of South Tyrol (northern Italy). Further, the impact of environmental site characteristics on the number and concentration of pesticides was assessed. Grass samples from the selected playgrounds were collected and screened for 315 pesticide residues using standard gas chromatography and mass spectrometry. Nearly half of the playgrounds (45%) were contaminated by at least one pesticide and a quarter (24%) by more than one. Eleven of the 12 different detected pesticides are classified as endocrine-active substances including the insecticide phosmet and the fungicide fluazinam showing the highest concentrations (0.069 and 0.26 mg kg−1, respectively). Additionally, one disinfectant and one preservation agent was found. Playgrounds in Venosta valley were most often contaminated (76% of all investigated playgrounds), highest concentrations were found in the Low Adige (2.02 mg kg−1). Pesticide concentrations were positively associated with areal proportion of apple orchards in the surroundings, the amount of rainfall and wind speed. In contrast, increasing global irradiance, opposite wind direction, increasing distance to agricultural sites and high wind speeds when pesticide application was not allowed were associated with decreasing pesticide contamination. This study is among the first investigating pesticide contamination of public playgrounds together with environmental factors in areas with pesticide-intensive agriculture at the beginning of the growing season. It is likely that playgrounds will be affected by more pesticides and higher concentrations over the course of the crop season. The result, that the majority of the detected pesticides are classified as endocrine active is worrisome as children are especially vulnerable. Hence, we recommend that pesticide risk assessments should better include protection measures for non-target areas.

Pesticides diazinon and diuron increase glutathione levels and affect multixenobiotic resistance activity and biomarker responses in zebrafish ( Danio rerio ) embryos and larvae

Abstract: Zebrafish have been increasingly used for monitoring and assessing the effects of different contaminants in the aquatic environments. In the present study, zebrafish embryos and larvae were used to study the effects of the insecticide diazinon and the herbicide diuron in regard to occurrence of oxidative stress-related cellular responses, multixenobiotic resistance (MXR)-related efflux transporter activity—which represents the first line of defense against xenobiotics in many aquatic organisms—and responses of different molecular and biochemical biomarkers. The recently established non-invasive quantitative plate assay, which uses the fluorescent probes CM-H2DCFDA and CellTracker™ Green CMFDA and measures the fluorescence in whole zebrafish larvae, was applied to assess changes in reactive oxidative species (ROS) and glutathione (GSH) after exposure to the investigated pesticides. The results showed a significant increase of GSH after 1 h exposure of zebrafish larvae to both diazinon and diuron. Regarding the ROS induction, no significant increases in fluorescence could be detected after 2 h exposure to the investigated pesticides. Applying a newly adapted assay for MXR activity, it was determined that diuron caused no change after a 24-h exposure, but caused a significant induction of MXR activity after a 48-h exposure (indicated by a decreased amount of accumulated rhodamine B). On the other hand, diazinon caused an inhibition of MXR activity after both 24 h and 48 h exposure (indicated by an increased amount of accumulated rhodamine B). Regarding the biomarkers, different set-ups and exposure periods were applied and both molecular (gene expression) and biochemical (enzymatic activities) responses were assessed. Diazinon caused an inhibition of carboxylesterase (CES) and acetylcholinesterase (AChE) activity in zebrafish larvae, diuron inhibited AChE activity in in vitro testing, and both pesticides significantly affected gene expression and activities of some of the cytochrome P450 (CYP) family enzymes. The obtained results show various effects of the investigated pesticides and will help to elucidate how aquatic animals cope with pesticides present in their environment. Additionally, the recently developed fluorescence-based assay and the newly adapted MXR activity assay proved to be useful tools for ecotoxicological risk assessment to further investigate pesticide effects.

Prioritising site-specific micropollutants in surface water from LC-HRMS non-target screening data using a rarity score

Abstract: Current compound prioritisation and monitoring approaches within Europe focus mainly on widely occurring priority and river basin specific pollutants but may overlook site-specific contamination from local emission sources. Thus, we propose a robust and semiautomated approach for the identification of site-specific chemicals and a prioritisation of water bodies with specific contamination based on non-target screening data from liquid chromatography coupled to high-resolution mass spectrometry. For prioritisation of site-specific contaminants, we calculated rarity scores for all peaks occurring in a set of 31 surface water samples, which combine the maximum signal intensity of a peak in a dataset with its frequency of occurrence in that dataset in one single number. These were a robust measure without the need to address the problems of missing data in more sophisticated multivariate statistical methods. For our dataset, site-specific compounds were defined for rarity scores > 1000, and the studied 31 sites showed a huge difference in the number of such peaks (0–91 in positive and 0–48 in negative ion mode). Together with isotopologue detection, the evaluation of mass defects and the occurrence of homologue series, which all could be obtained from automated data processing, a more detailed characterisation of these site-specific contaminations was possible. For three selected sites with a high number of site-specific peaks, novel or unexpected compounds could be identified, which stem from specific usage or (former) industrial production upstream of these sites. The proposed approach allows for a rapid screening of large non-target screening datasets for site-specific contaminants, the prioritisation of sites with such a specific contamination and the subsequent identification of these compounds. Thus, the risk of overlooking possibly hazardous chemicals (including unknowns) which are not covered in conventional monitoring and prioritisation schemes is reduced.

Prioritization of hazards of novel flame retardants using the mechanistic toxicology information from ToxCast and Adverse Outcome Pathways

Abstract: Flame retardants (FRs) are used in most consumer products and textiles to comply with current flammability standards. After the restriction of polybrominated diphenyl ethers, a large number of chemically diverse replacement FRs are increasingly used, but the risk they represent is not yet properly evaluated and their toxicity pathways are still poorly understood. We collected in vivo toxicological information on 62 (including 52 non-regulated) FRs and established five prioritization categories (Cat I to V) based on data availability and toxicological concern. We then considered available in vitro toxicological data from ToxCast, as a complement to in vivo information. By combining these information sources, we then explored relevant toxicity mechanisms for nine selected FRs (Cat I) using the AOP (Adverse Outcome Pathway) framework. For 20 FRs (Cat V), toxicological data on mammals were absent. Data available were scarce for another 22 FRs, of which 14 FRs (Cat II) may be of toxicological concern. We found substantial information for only ten replacement FRs, of which nine (Cat I) present some toxicological concern: tris-2-chloroethyl phosphate (TCEP), tris(1,3-dichloropropyl)phosphate (TDCIPP), triphenyl phosphate (TPhP), tricresyl phosphate (TMPP), tetrabromobisphenol A (TBBPA), tri-n-butyl phosphate (TNBP), tri(2-butoxyethyl) phosphate (TBOEP), tris(1-chloro-2-propyl) phosphate (TCIPP), 2-ethylhexyl diphenyl phosphate (EHDPP). ToxCast results confirmed in vivo based categorization for several FRs and identified potential molecular targets. For the nine Cat I FRs, we identified several molecular targets, health outcomes and some potential AOPs. However, the complete toxicity pathways leading from molecular targets to adverse health outcomes are still unknown, with the exception of TBBPA-induced neurotoxicity. The approach presented in this study was particularly useful for the categorization of a large group of replacement FRs with relatively low data availability. We highlight priority compounds that critically need more toxicological studies or FRs for which regulatory measures could be envisaged. Our research also suggests that high toxicity indicated by ToxCast is particularly relevant for predicting higher hazard in vivo. Finally, we indicate several gaps and directions for future research, such as molecular targets that could be tested in vitro and health outcomes for cohort studies.

The European Collaborative Project SOLUTIONS developed models to provide diagnostic and prognostic capacity and fill data gaps for chemicals of emerging concern

Abstract: The European Union Water Framework Directives aims at achieving good ecological status in member states’ water bodies. Insufficient ecological status could be the result of different interacting stressors, among them the presence of many thousands of chemicals. The diagnosis of the likelihood that these chemicals negatively affect the ecological status of surface waters or human health, and the subsequent development of abatement measures usually relies on water quality monitoring. This gives an incomplete picture of chemicals’ contamination, due to the limited number of monitoring stations, samples and substances. Information gaps thus limit the possibilities to protect against and effectively manage chemicals in aquatic ecosystems. The EU FP7 SOLUTIONS project has developed and validated a collection of integrated models (“Model Train”) to increase our understanding of issues related to emerging chemicals in Europe’s river basins and to complement information and knowledge derived from field data. Unlike pre-existing models, the Model Train is suitable to model mixtures of thousands of chemicals, to better approach a “real-life” mixture exposure situation. It can also be used to model new chemicals at a stage where not much is known about them. The application of these models on a European scale provides temporally and spatially variable concentration data to fill gaps in the space, time and substance domains left open by water quality monitoring, and it provides homogeneous data across Europe where water quality data from monitoring are missing. Thus, it helps to avoid overlooking candidate chemicals and possible hot spots for management intervention. The application of the SOLUTIONS Model Train on a European scale presents a relevant line of evidence for water system level prognostic and diagnostic impact assessment related to chemical pollution. The application supports the design of cost-effective programmes of measures by helping to identify the most affected sites and the responsible substances, by evaluating alternative abatement options and by exploring the consequences of future trends.

Variable withdrawal elevations as a management tool to counter the effects of climate warming in Germany’s largest drinking water reservoir

Abstract: Thermal stratification in reservoirs is a significant factor affecting water quality, and can be strongly influenced by climate change and operational strategies. Reservoirs in the temperate zone react most sensitively to climate warming during winter as ice cover and inversed stratification are about to disappear in a warmer world. In this study, two well-established hydrodynamic models, the one-dimensional General Lake Model (GLM) and the two-dimensional CE-QUAL-W2 (W2), were used to investigate the response of winter inversed stratification in the Rappbode Reservoir to future climate warming, combined with different water withdrawal elevations. Under increased air temperature, the duration of inversed stratification is reduced and the inversion phenomenon will entirely disappear under current management if the air temperature is increased high enough (more than 4.5 K) in the future. Under strong climate warming, the Rappbode Reservoir will therefore change from a dimictic to a monomictic mixing type. Changing the reservoir management from deep withdrawal (e.g., below 350 m a.s.l.) to shallow withdrawal elevations (e.g., above 390 m a.s.l.) reduces internal heat energy stored in the reservoir in summer and prolongs the inversed stratification period in winter. This strategy can retain the dimictic behavior even under strong warming. Our study indicates that adjusting the withdrawal elevation is an effective management instrument to control the winter conditions and can, in fact, mitigate climate warming effects on winter hydrodynamics by stabilizing the dimictic mixing type.

Climate finance and green growth: reconsidering climate-related institutions, investments, and priorities in Nepal

Abstract: Nepal, a least-developed, mountainous, and land-locked country is consistently ranked as one of the most vulnerable countries to the climate change. Poor socioeconomic development, rough and highly unstable geography, inadequate institutional capacity to deal with research, development and policy and mostly underdeveloped infrastructures, all have contributed to increasing vulnerability of communities and ecosystems, and have limited their adaptive capacity. Over the past decade, Nepal has made significant progress, particularly in developing and implementing policies and frameworks and establishing institutional mechanisms with the support of donor countries, UN and multilateral agencies. As the global climate politics is getting more complicated, international financing patterns—both climate and development finance—are shifting their ways, forcing the countries like Nepal to diversify the funding base for climate change actions and integrate them within national development plans and strategies. Using the data and information currently available, we analyze the existing financing situations, discuss the future scenarios and suggest policy recommendations to develop a set of long-term adaptation and impact mitigation strategies in specific and environmental change at large. When short-term adaptation strategies funded from existing financial arrangements and other related bilateral and multilateral sources particularly European countries, seem to be encouraging, we stress the need of “public–private partnership-driven full-fledged green economy” focusing on renewable energy and transport, agriculture and forestry, water and water-induced disasters, as well as tourism and hospitality.

Liver toxicity assessments in rats following sub-chronic oral exposure to copper nanoparticles

Abstract: The widespread use of nano-copper as a feed additive in the absence of toxicological studies has potential risks to humans and animals. Toxicity studies on nano-copper in animals usually exposure from the respiratory tract, however, it is necessary to study the oral exposure toxicity of nano-copper to understand its risks as a feed additive. Currently the hepatotoxicity and mechanism of nano-copper after sub-choronic oral exposure at equivalent doses of 50, 100, and 200 mg/kg/day were evaluated in rats; micro-copper and Cu ions were used as controls. Nano-copper (200 mg/kg) increased serum alanine aminotransferase and aspartate aminotransferase significantly, further promoting hepatic oxidative stress, inflammation, and corresponding histopathological changes, and exhibited significant dose-dependent changes. Nano-copper also decreased the level of nuclear receptors, resulting in significant reductions in mRNA, protein, and activity of hepatic CYP450 enzymes. The molecular mechanisms responsible for these toxic effects involved the signaling pathway of NF-κB, MAPK, and STAT5. Nano-copper caused strong hepatic toxicity by inducing oxidative stress and inflammation. The decreased drug metabolism enzymes lead to nano-copper–drug interaction that provoked the concerns on animal-derived food safety.

Novel brominated flame retardants in house dust from Shanghai, China : levels, temporal variation, and human exposure

Abstract: Novel brominated flame retardants (NBFRs) have been increasingly used as alternatives to legacy BFRs (e.g., PBDEs and HBCDs) in consumer products, but are liable to emigrate and contaminate indoor dust. In this study, a total of 154 house dust samples including floor dust (FD) and elevated surface dust (ESD) were collected in the biggest metropolitan area (Shanghai) of East China in 2016. Limited information about temporal variation of NBFRs indoors is available, while the period of sampling is influential in human exposure estimates. Levels, temporal variation, and human exposure of seven target NBFRs such as decabromodiphenylethane (DBDPE), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EHTBB), and bis(2-ethylhexyl) tetrabromophthalate (BEHTEBP) were investigated in indoor house dust. Concentrations of ∑7NBFRs ranged from 19.11 to 3099 ng/g with a geomean of 295.1 ng/g in FD, and from 34.74 to 404.6 ng/g with a geomean of 117.9 ng/g in ESD. The geomeans of DBDPE were 219.6 ng/g in FD and 76.89 ng/g in ESD, accounting for 90.5% and 80.5% of ∑7NBFRs. Levels of EHTBB, BTBPE, and DBDPE in FD exceeded significantly those in ESD. The temporal variation in ∑7NBFRs in FD was ranked as summer > winter > autumn > spring. The daily exposure doses (DEDs) of ∑7NBFRs via dust ingestion decreased as: infants > toddlers > children > teenagers > adults. Infants showed the highest DED in FD, 9.1 ng/kg bw/day. DBDPE clearly dominated the NBFRs in both FD and ESD, but the concentrations of DBDPE in this study were generally moderate compared with the other international studies. Dust ingestion was the major pathway of human exposure to NBFRs indoors. About eightfold difference in exposure estimates between infants and adults showed that infants faced elevated exposure risks in FD. This study highlighted the necessity to estimate human exposure of NBFRs for different age groups using FD and ESD, respectively.

Magnitude and influence of atmospheric phosphorus deposition on the southern Baltic Sea coast over 23 years: implications for coastal waters

Abstract: There are various ways for nutrients to enter aquatic ecosystems causing eutrophication. Phosphorus deposition through precipitation can be one pathway, besides point sources, like rivers, and diffuse runoff from land. It is also important to evaluate recent trends and seasonal distribution patterns of phosphorus deposition, as important diffuse source. Therefore, a long-term dataset was analysed including 23 years of daily phosphate bulk depositional rates and 4.5 years of total phosphorus (TP) bulk depositional rates. The study area was at the coastline of the southern Baltic Sea, an area which shows severe eutrophication problems. The median daily deposition of phosphate was 56 µg m−2 day−1 (1.8 µmol m−2 day−1) at 4222 rain events. The median annual sum of phosphate deposition was 16.7 kg km−2 a−1, which is comparable to other European areas. The annual TP deposition depended strongly on methodological aspects, especially the sample volume. The median TP-depositional rates ranged between 19 and 70 kg km−2 a−1 depending on the calculated compensation for missing values, as not every rain event could be measured for TP. The highest TP-depositional rates were measured during summer (e.g. up to 9 kg TP km−2 in August 2016). There was no trend detectable for phosphate- and TP-depositional rates over the sampled period. Deposition of P is a considerable nutrient flux for coastal waterbodies. Median total annual deposition contributed 3 t (phosphate) to 10 t (TP) per year into the adjacent lagoon system, being therefore close to annual riverine inflows of 10 t phosphate and 20 t TP per year. However, the impact of precipitation is predicted to be higher in lagoon parts with fewer point sources for phosphorus, if equally distributed over the area of interest.

Assessing the ecological impact of chemical pollution on aquatic ecosystems requires the systematic exploration and evaluation of four lines of evidence

Abstract: The aim of the European Water Framework Directive is to ensure good ecological status for all European surface waters. However, although current monitoring strategies aim to identify the presence and magnitude of ecological impacts, they provide little information on the causes of an ecosystem impairment. In fact, approaches to establish causal links between chemical pollution and impacts on the ecological status of exposed aquatic systems are largely lacking or poorly described and established. This is, however, crucial for developing and implementing appropriately targeted water management strategies. In order to identify the role of chemical pollution on the ecological status of an aquatic ecosystem, we suggest to systematically combine four lines of evidence (LOEs) that provide complementary evidence on the presence and potential ecological impact of complex chemical pollution: (1) component-based methods that allow a predictive mixture risk modeling; (2) effect-based methods; (3) in situ tests; (4) field-derived species inventories. These LOEs differ systematically in their specificity for chemical pollution, data demands, resources required and ecological relevance. They complement each other and, in their combination, allow to assess the contribution of chemical pollution pressure to impacts on ecological structure and function. Data from all LOEs are not always available and the information they provide is not necessarily consistent. We therefore propose a systematic, robust and transparent approach to combine the information available for a given study, in order to ensure that consensual conclusions are drawn from a given dataset. This allows to identify critical data gaps and needs for future testing and/or options for targeted and efficient water management.