Annual Average Environmental Quality Standards Research Articles

Bioavailability-based Environmental Quality Standards for metals under the Water Framework Directive

Metals are naturally present in surface waters. By considering the bioavailability of a metal in an aquatic environment, we can more precisely predict the effect of a selected metal on aquatic organisms. This enables us to make a more reliable assessment of the compliance of the metal's concentration in inland surface waters with the environmental quality standard for that metal. In addition to complex-forming inorganic and organic ligands, the bioavailability of metals in water is also influenced by physicochemical conditions in the water. Metals occur in different concentrations and in different forms in aquatic environments. This is referred to as metal speciation. The bioavailability of a metal in water depends mainly on its speciation. Normally, a dissolved free metal ion is more bioavailable than a metal ion bound in a complex. The risks posed by given metals to aquatic environments are addressed under EU legislation in the Water Framework Directive (Council of the European Union, 2000) (WFD). The WFD’s purpose is to direct Member States to protect and improve the status of all water bodies throughout the European Union. Directive 2013/39/EC (Council of the European Union, 2013), which refers to priority substances as regards water policy, supplements the WFD and the Directive on environmental quality standards (Council of the European Union, 2008). For nickel and lead, Directive 2013/39/EC sets the annual average environmental quality standards (AA-EQS) for inland surface waters, which refer to biologically available concentrations of metals (AA-EQSbioavailable). In this way, uniform environmental quality standards for the entire European Union are determined for metals, allowing for a compliance assessment of metals for surface waters. In the article, we have presented an analysis of inland surface water monitoring data for nickel and lead, examining how the introduction of AA-EQSbioavailable affects the consistency of monitoring data for these metals. We used monitoring data from 2018 to 2021. To calculate bioavailable concentrations for nickel and lead, we used the bioavailability assessment model bio-met bioavailability tool v.2.3 (Bio-met, 2017). Additionally, for lead, we used equations (1), (2), and (3) to calculate the bioavailable concentration (European Commission, 2019). Based on the analysis conducted, we recommend the utilization of the bio-met model instead of the equations for calculating the concentration of bioavailable lead in the context of the annual compliance assessment of inland surface water monitoring data carried out by ARSO. Using the mentioned bioavailability assessment model, we have provided an upgrade in the methods used to assess metal’s concentration compliance with the EQS for that metal for surface waters. As a result, the requirements of Directive 2013/39/EC relating to biologically available concentrations of metals could be transferred to the Slovenian legal system.

Inputs of Total and Labile Dissolved Metals from Six Facilities Continuously Discharging Treated Wastewaters to the Marine Environment of Gran Canaria Island (Canary Islands, Spain).

The presence of ten metals (Cd, Ni, Pb, Cr, Cu, Zn, Al, Fe, Mn, and Co) was investigated in the final discharge of six facilities, including four wastewater treatment plants, which were continuously discharging treated wastewater to the coastal environment in Gran Canaria Island. A four-day sampling campaign was carried out at each facility in July 2020, in which both the spot samplings technique and the diffusive gradient in thin-film technique (DGT) were carried out to measure total dissolved metals and the in situ labile metal fraction, respectively. After the necessary sample preparation steps, measurements were carried out by ICP-MS for both samplings. Raw data referred to the spot total dissolved and DGT-labile metal concentrations were reported. In general, the average metal concentrations were dispersed in a broad range. As expected, the highest metal contents were found in those facilities with larger industrial contributions. The values of annual average environmental quality standards (AA-EQS) were used to assess the total dissolved metal concentrations for every metal in every final discharge. In only one of the studied facilities, some metals (Ni and Zn) exceeded these EQS within the receiving waterbody, highlighting the need for more efficient treatment targeted towards a specific discharging-water quality. In addition, the total dissolved and labile metal daily fluxes of discharge were calculated to estimate the contribution of every effluent to the receiving water bodies.

Comparative evaluation of river chemical status based on WFD methodology and CCME water quality index

The Water Framework Directive (WFD) methodology, proposed by the Ministry of Environment and Energy of Greece (WFD-MEEG), and the Canadian Council of Ministers of Environment Water Quality Index (CCME-WQI) are comparatively applied to evaluate the chemical status of a major transboundary river. Water quality parameters were monitored at 11 sites along the main stream of the river and its main tributaries, and at five sites in the reservoirs, on a monthly frequency, in the period from May 2008 to May 2009. Water temperature (T), dissolved oxygen (DO), pH, and electrical conductivity (EC) were measured in-situ, while water samples were collected for the determination of total suspended solids (TSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), nitrite-, nitrate- and ammonium-nitrogen, total Kjeldahl nitrogen (TKN), ortho-phosphates (OP), total phosphorus (TP), and chlorophyll-a (Chl-a). The water samples were also analyzed for the determination of seven heavy metals (i.e., Cd, Pb, Hg, Ni, Cr, Cu, Zn) and 33 priority substances, as listed in Annex II of EU Directive 2008/105/EC. The results showed that the physicochemical parameters (i.e., T, DO, pH, EC, inorganic nitrogen, TKN, OP, TP, TSS, and Chl-a) were within the natural range. The mean concentration of the measured heavy metals did not exceed the limits set by WHO (2003, 2017) for drinking water. Regarding the priority substances, some of them (i.e., anthracene, fluoranthene, and polyaromatic hydrocarbons) were measured in various stations at higher concentrations than the Annual Average Environmental Quality Standards (AA-EQS). Based on the WFD-MEEG methodology, the river water was in the ‘good’ quality class, while according to CCME-WQI the river quality ranged from ‘marginal’ to ‘good’ category. It seems that CCME-WQI is stricter than WFD-MEEG but could be a WQI appropriate for use.

Chemical surveillance in freshwaters: small sample sizes underestimate true pollutant loads and fail to detect environmental quality standard exceedances

BackgroundChemical surveillance in surface waters is crucial to identify potential threats to the health of freshwater ecosystems. Usually, the concentrations of pollutants are highly variable over the course of the year and often result in non-normally distributed data sets. Therefore, the European Water Framework Directive recommends measuring, e.g. priority substances at least 12 times a year to achieve an acceptable accuracy level for the estimation of the true mean annual loads. However, in Europe priority substances are often measured much less frequently. In this context, the aim of the present study was to analyze how sample size, temporal variability and skewness of the data sets influence the accuracy of the mean annual load estimation and the assessment of annual average environmental quality standards. For this purpose, sample size simulations using weekly composite samples of benzo(a)pyrene, 4-tert-octylphenol, fluoranthene and di(2-ethylhexyl) phthalate, selected as representatives for priority substances, were carried out.ResultsThe sample size simulations showed two general patterns: the accuracy of the mean annual load estimation increased with increasing sample size and skewness and temporal variability were more apparent in smaller sample sizes. In right-skewed data sets, small sample sizes led, on average, to a systematic underestimation of the true mean annual load whilst in a few cases these led to an overestimation. Although the study was carried out on priority substances, results can be transferable to other pollutants. Furthermore, in small sample sizes a considerable proportion of the simulated means failed to detect annual average environmental quality standard exceedances.ConclusionsThe results of the present study indicate that the usage of small sample sizes is likely to result in an underestimation of the true mean annual pollutant loads in chemical surveillance and scientific research, thus potentially jeopardizing the validity of results. Therefore, it is recommended to avoid the usage of small sample sizes for the determination of mean annual pollutant loads. Furthermore, priority substances should be sampled according to the European Water Framework Directive guidelines at least 12 times/year to improve the assessment of the threat posed by pollutants to freshwater ecosystems in Europe.

Perfluoroalkyl acids (PFAAs): Distribution, trends and aquatic ecological risk assessment in surface water from Tagus River basin (Spain)

Rivers can receive the input of treated or untreated sewage effluents from wastewater treatment plants, urban and industrial discharges and agricultural run-off, becoming an important pathway for the transport and mobilization of pollutants to the oceans. In the present study, the occurrence of 20 PFAAs was determined in the water of Tagus River basin (Spain). PFAAs were detected in 76 out of 92 water samples collected during 5 years (2013–2018), being perfluorooctanesulfonic acid (PFOS) the predominant compound (<0.01–34 ng/L). The annual average PFOS concentrations (2.9–11 ng/L) detected in Tagus River were above the annual average environmental quality standards (AA-EQS) established in the Directive, 2013/39/EU (0.65 ng/L for inland surface waters) but below the maximum allowable concentration (MAC-EQS; 36000 ng/L). The levels of PFAAs detected in urban and industrial areas were statistically higher (p < 0.01) than those at background or remote areas. The mass flow rates amounted to <0.01–46 kg/y for PFOS and <0.01–22 kg/y for perfluorooctanoic acid (PFOA). A quantitative ecotoxicological risk assessment was conducted to evaluate the environmental potential risk related to PFAAs in the aquatic ecosystem. Risk characterization ratios (RCRwater, RCRsed and RCRoral, fish) were below 1 in all cases.

Screening hundreds of emerging organic pollutants (EOPs) in surface water from the Yangtze River Delta (YRD): Occurrence, distribution, ecological risk

Increased synthetic chemical production and diversification in developing countries caused serious aquatic pollution worldwide with emerging organic pollutants (EOPs) detected in surface water rising health concerns to human and aquatic ecosystem even at low ng/L concentration with long-term exposure. The Yangtze River Delta (YRD) area serves agriculture and industry for people in eastern China. However, the current knowledge on the occurrence and ecological risk of diverse EOPs which are present in the aquatic environment is limited. This study was to investigate the complexity and diversity of EOPs in surface water from 28 sampling sites, which were selected to represent urban, industrial or agriculture areas in the YRD area. In total 484 chemicals were analyze by a target screening approach using liquid chromatography coupled to high-resolution tandem mass spectrometry (LC-HRMS/MS). 181 out of 484 EOPs were detected at least one site in the YRD area, and 44 analytes, mostly industrial chemicals and pesticides, were ubiquitous at all sampling sites. Most EOPs were industrial chemicals with 1H-benzotriazole and organophosphate flame retardants (PFRs) as the chemicals with highest concentrations. For 21 pesticides, mostly herbicides, maximum concentrations of atrazine and isoproturon were above the annual average environmental quality standards of Europe. Amantadine and DEET were the dominant pharmceuticals and personal care products (PPCPs) in the YRD area. Compared to urban areas (mostly in Qinhuai River), chemical profiles from industrial areas were more complex. Industrial activities likely have a strong impact on the composition of chemical mixtures in surface water from the YRD area. ISO E Super, 4-methylbenzylidene camphor and clotrimazole detected in this study are potentially persistent and bioaccumulative chemicals. Furthermore, results of risk assessment showed that hazard quotients of dimethyldioctadecylammonium, didecyldimethylammonium and octocrylene were higher than one and occur frequently, which indicates possibly adverse effects on fish species in the YRD area.

Modelling the effects of PSII inhibitor pulse exposure on two algae in co-culture.

A weakness of standard testing procedures is that they do not consider interactions between organisms, and they focus only on single species. Furthermore, these procedures do not take into account pulse exposure. However, pulse exposure is of particular importance because in streams, after crop application and during and after precipitation, herbicide concentrations fluctuate widely and can exceed the Annual Average Environmental Quality Standards (AA-EQS), which aim to protect the aquatic environment. The sensitivity of the algae Scenedesmus vacuolatus and Pseudokirchneriella subcapitata in a co-culture exposed to pulses is thus analysed in this study. As a first step, the growths of the algae in co-culture are investigated. For initial cell densities fixed, respectively, to 100,000 and 50,000 cells/mL, the growth of each alga is exponential over at least 48 h. S. vacuolatus seems to influence the growth of P. subcapitata negatively. Allelopathy is a possible explanation for this growth inhibition. The toxicity of the herbicide isoproturon is later tested on the algae S. vacuolatus and P. subcapitata cultured alone and in the co-culture. Despite the supplementary stress on the algae in the co-culture competing for nutrients, the toxicity of the herbicide is lower for the two algae when they are in the co-culture than when they are in separated culture. A model is adapted and used to predict the cell-density inhibition on the alga S. vacuolatus in the co-culture with the alga P. subcapitata exposed to a pulse concentration of isoproturon. Four laboratory experiments are performed to validate the model. The comparison between the laboratory and the modelled effects shows good agreement. The differences can be considered minor most of time. For future studies, it is important to ensure that the cell count is precise, as it is used to determine the parameters of the model. The differences can be also induced by the fact that the cell number of the alga P. subcapitata re-suspended in a new OECD medium after the centrifugation process cannot be fixed.

Effect-based tools for monitoring estrogenic mixtures: Evaluation of five in vitro bioassays

In vitro estrogen receptor transactivation assays (ERTAs) are increasingly used to measure the overall estrogenic activity of environmental water samples, which may serve as an indicator of exposure of fish or other aquatic organisms to (xeno)estrogens. Another potential area of application of ERTAs is to assist the monitoring of the potent steroids 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) under the Water Framework Directive (WFD) watch-list mechanism. Chemical analysis of E2 and EE2 is currently hampered by limits of quantification being mostly above the proposed annual average Environmental Quality Standards (AA-EQS) of 0.4 and 0.035 ng/L, respectively. Sensitive ERTAs could circumvent current detection challenges by measuring total estrogenic activity expressed as E2-equivalent (EEQ) concentrations.However, the use of different ERTAs results in different EEQ concentrations for the same sample. Reasons for these differences are known, but it remains unclear how to use and interpret bioassay results in a harmonised way. The aim of this study was to compare the intra- and inter-day variability of EEQ measurements using five different ERTAs (YES, ERα-CALUX, MELN, T47D-KBluc and GeneBLAzer-ERα) with regard to their applicability as effect-based tools in environmental monitoring.Environmentally relevant artificial mixtures of (xeno)estrogens were prepared to represent samples with higher (i.e. multiple times the AA-EQS for E2) or lower pollution levels (i.e. around the AA-EQS for E2). Mixtures were tested either directly or following solid phase extraction (SPE). The SPE step was included, as environmental samples typically require enrichment before analysis. Samples were analysed repeatedly to test intra-day and inter-day variability. Estrogenicity was quantified using the 10% effect level (PC10) of the positive control (E2) and expressed as EEQ concentrations.The average coefficient of variation (CV) of EEQ concentrations for the five ERTAs and all samples was 32%. CV was lower for intra-day experiments (30%) compared to inter-day experiments (37%). Sample extraction using SPE did not lead to additional variability; the intra-day CV for SPE extracted samples was 28%. Of the five ERTAs, ERα-CALUX had the best precision and repeatability (overall CV of 13%).

Modelling the effects of pulse exposure of several PSII inhibitors on two algae

Subsequent to crop application and during precipitation events, herbicides can reach surface waters in pulses of high concentrations. These pulses can exceed the Annual Average Environmental Quality Standards (AA-EQS), defined in the EU Water Framework Directive, which aims to protect the aquatic environment. A model was developed in a previous study to evaluate the effects of pulse exposure for the herbicide isoproturon on the alga Scenedesmus vacuolatus. In this study, the model was extended to other substances acting as photosystem II inhibitors and to other algae. The measured and predicted effects were equivalent when pulse exposure of atrazine and diuron were tested on S. vacuolatus. The results were consistent for isoproturon on the alga Pseudokirchneriella subcapitata. The model is thus suitable for the effect prediction of phenylureas and triazines and for the algae used: S. vacuolatus and P. subcapitata. The toxicity classification obtained from the dose–response curves (diuron>atrazine>isoproturon) was conserved for the pulse exposure scenarios modelled for S. vacuolatus. Toxicity was identical for isoproturon on the two algae when the dose–response curves were compared and also for the pulse exposure scenarios. Modelling the effects of any pulse scenario of photosystem II inhibitors on algae is therefore feasible and only requires the determination of the dose–response curves of the substance and growth rate of unexposed algae. It is crucial to detect the longest pulses when measurements of herbicide concentrations are performed in streams because the model showed that they principally affect the cell density inhibition of algae.

In vitro bioassays to screen for endocrine active pharmaceuticals in surface and waste waters

In the context of the European Water Framework Directive (WFD) it is fully recognized that pharmaceuticals can represent a relevant issue for the achievement of the good chemical and ecological status of European surface water bodies. The recent European Directive on the review of priority substances in surface water bodies has included three pharmaceuticals of widespread use (diclofenac, 17α-ethinylestradiol (EE2), 17β-estradiol (E2)) in the European monitoring list, the so-called watch list. Endocrine active pharmaceuticals such as EE2 and E2 (also occurring as natural hormone) can cause adverse effects on aquatic ecosystems at very low levels. However, monitoring of these pharmaceuticals within the watch list mechanism of the WFD and national monitoring programs can be difficult because of detection problems of most routine analytical methods. With proposed annual average Environmental Quality Standards (AA-EQS) of 0.035ng/L and 0.4ng/L, respectively, the estrogenic pharmaceutical EE2 and the natural hormone E2 are among those substances. Sensitive in vitro bioassays could reduce the current detection problems by measuring the estrogenic activity of environmental samples. In a short review article the application of this approach to screen and assess the risks of endocrine active pharmaceuticals with a focus on estrogenic pharmaceuticals in environmental waters is discussed.

Picogram per liter detections of pyrethroids and organophosphates in surface waters using passive sampling

Pyrethroids and organophosphates are among the most toxic insecticides for aquatic organisms, leading to annual-average environmental quality standards (AA-EQS) in the picogram per liter range in surface waters. For monitoring purposes, it is therefore crucial to develop very sensitive analytical methods. Until now, it is very difficult to reach detection limits at or below given AA-EQSs. Here, we present a passive sampling method using silicone rubber (SR) sheets for the sampling of ten pyrethroids and two organophosphates in surface waters. An analytical method was developed, optimized and validated for the extraction of the insecticides from the SR sheets by accelerated solvent extraction followed by clean-up on C18 and silica gel and detection with GC–MS/MS in positive ionization mode. Good precision (<20%) and absolute recovery (>50%) was observed for all substances, accuracy was between 66% and 139%. Limits of detection between 6 and 200 pg/L were achieved for all substances in surface waters using average sampling rates for PCBs and PAHs. The lack of substance-specific sampling rates and missing performance reference compounds led to an uncertainty in the concentration estimation of factor three in both directions. In a large field study, comprising 40 environmental samples from nine Swiss rivers, eight out of 12 substances were detected (most frequently: chlorpyrifos, cypermethrin). Most of the estimated organophosphate concentrations were between 0.1 and 1 ng/L, most pyrethroid detections below 0.1 ng/L. Four substances (chlorpyrifos-methyl, cypermethrin, deltamethrin and lambda-cyhalothrin) showed exceedances of their respective AA-EQS in multiple samples, also when the uncertainties in the concentration estimation were considered. As pyrethroid and organophosphate detection by SR passive sampling is very practicable and allows sensitive analysis, it has the potential to become a new tool in the monitoring of non-polar pesticides.

New priority substances of the European Water Framework Directive: Biocides, pesticides and brominated flame retardants in the aquatic environment of Denmark

The biocides cybutryn (Irgarol) and terbutryn, the herbicides aclonifen and bifenox, the insecticides cypermethrin and heptachlor/heptachlor epoxide and the brominated flame retardant hexabromocyclododecane (HBCD) are new priority substances of the Water Framework Directive of the European Union. In order to gain knowledge about their presence in the aquatic environment in an off-season situation with regard to pesticide and biocide applications, these substances were analysed in freshwater, seawater and fish samples from Denmark. Aclonifen, bifenox, cypermethrin and heptachlor were below the limits of detection (LODs) in all samples. However, the LODs for cypermethrin and heptachlor exceeded the annual average environmental quality standards (AA-EQSs). Cybutryn, terbutryn, heptachlor epoxide and HBCD were detected in the majority of samples, with detection frequencies of 100% for heptachlor epoxide and HBCD in water and 90% in fish. No concentration was above maximum allowable concentration (MAC)-EQS values, but AA-EQS values were exceeded for all four compounds by several samples, including 100% of the water samples with regard to heptachlor epoxide. Methodological issues remain for cypermethrin, and to a certain extent for heptachlor/heptachlor epoxide, for which water LODs were above AA-EQSs although a water volume of 12L was combined with very sensitive high resolution mass spectrometry.

Development of sediment quality guidelines for freshwater ecosystems

The development of Sediment Quality Guidelines (SQGs) is one of the remaining challenges for a better protection of aquatic biodiversity and in particular sediment dwelling organisms. So far, sediment quality assessment in Flanders was based on a comparison of chemical concentrations to the geometric mean of the concentrations at 12 reference sites. The study described in this paper addressed the need for more science-based guidelines. The developed guidelines are already incorporated into Flemish legislation. Based on a large sediment monitoring database, containing physico-chemical properties, concentrations of chemicals, macrobenthic community assemblages and ecotoxicological data, Sediment Effect Concentrations (SECs) were calculated as basis for the SQGs. The derived SECs were based on ecological effects, namely Lowest and Severe Effect Levels (LEL/SEL), as well as ecotoxicological endpoints, namely Threshold and Probable Effect Levels (TEL/PEL). The average values of the ecological and ecotoxicological SECs were used to distinguish five sediment quality classes. The ecological values were in general less stringent than the ecotoxicological values. However, the Lowest Effect Levels (95% of the benthic taxa can be present under this level) and Threshold Effect Levels (no toxic effect is expected under this level) did not differ significantly. Probable Effect Levels (concentrations above this level will certainly result in toxic effects) were generally lower than the Severe Effect Levels (above this level only 5% or less of the taxa are present). The SECs calculated in this study enabled us to correctly identify 87.9% of the sediments as toxic. The development of SQGs based on a combination of the LEL/SEL and TEL/PEL methods enabled us to underpin these SQGs based on field observations and will improve the assessment of sediment quality based on chemical parameters. Although sediments typically contain complex mixtures of contaminants, only a limited number of these contaminants will be measured. Additional application of bioassays for the overall sediment quality assessment is therefore recommended. This study describes the development of SQGs in Flanders, which are based on ecological and ecotoxicological data derived from a TRIAD monitoring network. The combination of the LEL and PEL resulted in SQGs that were recently incorporated in Flemish legislation and for which the respective pore water concentrations were in the same order of magnitude as the Annual Average Environmental Quality Standards values for Water Framework Directive priority pollutants.

Sources and Potential Effects of Copper and Zinc Concentrations in the Estuarine Waters of Essex and Suffolk, United Kingdom

This paper evaluates the possible biological significance of routine monitoring data for dissolved copper and zinc collected from nine lightly industrialized Essex and Suffolk estuaries by the Environment Agency during the years 1992–96, and investigates the relative importance of the various sources. The annual average concentration data from several locations in each estuary are compared with the proposed revised UK annual average Environmental Quality Standards (EQSs) for dissolved copper (5 μ g l −1) and zinc (10 μ g l −1) in seawater. In summary, 21.7% of sampling-location/year combinations exceeded the revised EQS for copper, and 53.6% exceeded the revised EQS for zinc, and one or more locations on each estuary failed each EQS for at least one year in the five-year period. In some of the nine estuaries, riverine and treated sewage discharges contribute a significant proportion of the total copper and zinc input, but the single largest source of both metals is almost certainly boating traffic employing copper-based antifouling paints and zinc-based sacrificial anodes. The data suggest that both metals may be causing ecological damage, but this cannot be firmly concluded because an unknown proportion of each was probably complexed with dissolved organic matter, and therefore less bioavailable. This question can only be addressed by field studies of the biological status of indicator species in these waters.