Maja Kuzmanovic

Risk assessment based prioritization of 200 organic micropollutants in 4 Iberian rivers

The use of chemicals is continuously growing both in total amount as well as in a number of different substances, among which organic chemicals play a major role. Owing to the growing public awareness on the need of protecting both ecosystems and human health from the risks related to chemical pollution, an increasing attention has been drowned to risk assessment and prioritization of organic pollutants. In this context, the aims of this study were (a) to perform an environmental risk assessment for 200 organic micropollutants including both regulated and emerging contaminants (pesticides, alkylphenols, pharmaceuticals, hormones, personal care products, perflourinated compounds and various industrial organic chemicals) monitored in four rivers located in the Mediterranean side of the Iberian Peninsula, namely, the Ebro, Llobregat, Júcar and Guadalquivir rivers; and (b) to prioritize them for each of the four river basins studied, taking into account their observed concentration levels together with their ecotoxicological potential. For this purpose, a prioritization approach has been developed and a resulting ranking index (RI) associated with each compound. Ranking index is based on the measured concentrations of the chemical in each river and its ecotoxicological potential (EC50 values for algae, Daphnia sp. and fish). Ten compounds were identified as most important for the studied rivers: pesticides chlorpyriphos, chlorfenvinphos, diazinon, dichlofenthion, prochloraz, ethion carbofuran and diuron and the industrial organic chemicals nonylphenol and octylphenol that result from the biodegration of polyethoxylated alkyphenol surfactants. Also, further research into chronic toxicity of emerging contaminants is advocated.

Ecotoxicity of sediments in rivers: Invertebrate community, toxicity bioassays and the toxic unit approach as complementary assessment tools

The determination of the real toxicity of sediments in aquatic ecosystems is challenging and necessary for an appropriate risk assessment. Different approaches have been developed and applied over the last several decades. Currently, the joint implementation of chemical, ecological and toxicological tools is recommended for an appropriate and successful toxicity risk assessment. We chose the combination of the toxic unit approach with acute pore water tests (Vibrio fischeri, Pseudokirchneriella subcapitata and Daphnia magna) and whole-sediment exposure tests (V. fischeri, Chironomus riparius), together with invertebrate community composition (multivariate analyses) to detect short and long-term responses of the organisms in four rivers of the Iberian Peninsula. High toxicity was detected in three sites (the downstream sites of the Llobregat and the Júcar, and the most upstream site of the Ebro). We identified organophosphate insecticides and metals as the main variables responsible for this toxicity, particularly in the whole-sediment tests. In particular, chlorpyrifos was mostly responsible for the toxicity (TUs) of D. magna, coinciding with the C. riparius mortality (long-term toxicity) in the mentioned sites, and copper was the main pollutant responsible for the short-term toxicity of P. subcapitata. The combination of the different approaches allowed us to detect ecotoxicological effects in organisms and identify the main contributors to the toxicity in these multi-stressed rivers.

Emission factor estimation of ca. 160 emerging organic microcontaminants by inverse modeling in a Mediterranean river basin (Llobregat, NE Spain)

Starting from measured river concentrations, emission factors of 158 organic compounds out of 199 analyzed belonging to different groups of priority and emerging contaminants [pesticides (25), pharmaceuticals and hormones (81), perfluoroalkyl substances (PFASs) (18), industrial compounds (12), drugs of abuse (8) and personal care products (14)] have been estimated by inverse modeling. The Llobregat river was taken as case study representative of Mediterranean rivers. Industrial compounds and pharmaceuticals are the dominant groups (range of 10(4) mg·1000 inhab(-1)·d(-1)). Personal care products, pesticides, PFASs and illegal drugs showed a load approximately one order of magnitude smaller. Considered on a single compound basis industrial compounds still dominate (range of ca. 10(3) mg·1000 inhab(-1)·d(-1)) over other classes. Generally, the results are within the range when compared to previously published estimations for other river basins. River attenuation expressed as the percentage fraction of microcontaminants eliminated was quantified. On average they were around 60-70% of the amount discharged for all classes, except for PFASs, that are poorly eliminated (ca. 20% on average). Uncertainties associated with the calculated emissions have been estimated by Monte-Carlo methods (15,000 runs) and typically show coefficients of variation of ca. 120%. Sensitivities associated with the various variables involved in the calculations (river discharge, river length, concentration, elimination constant, hydraulic travel time and river velocity) have been assessed as well. For the intervals chosen for the different variables, all show sensitivities exceeding unity (1.14 to 3.43), tending to amplify the variation of the emission. River velocity and basin length showed the highest sensitivity value. Even considering the limitations of the approach used, inverse modeling can provide a useful tool for management purposes facilitating the quantification of release rates of chemicals into the aquatic environment.

Integrated Risk Index of Chemical Aquatic Pollution (IRICAP): case studies in Iberian rivers.

The hazard of chemical compounds can be prioritized according to their PBT (persistence, bioaccumulation, toxicity) properties by using Self-Organizing Maps (SOM). The objective of the present study was to develop an Integrated Risk Index of Chemical Aquatic Pollution (IRICAP), useful to evaluate the risk associated to the exposure of chemical mixtures contained in river waters. Four Spanish river basins were considered as case-studies: Llobregat, Ebro, Jucar and Guadalquivir. A SOM-based hazard index (HI) was estimated for 205 organic compounds. IRICAP was calculated as the product of the HI by the concentration of each pollutant, and the results of all substances were aggregated. Finally, Pareto distribution was applied to the ranked lists of compounds in each site to prioritize those chemicals with the most significant incidence on the IRICAP. According to the HI outcomes, perfluoroalkyl substances, as well as specific illicit drugs and UV filters, were among the most hazardous compounds. Xylazine was identified as one of the chemicals with the highest contribution to the total IRICAP value in the different river basins, together with other pharmaceutical products such as loratadine and azaperol. These organic compounds should be proposed as target chemicals in the implementation of monitoring programs by regulatory organizations.

Environmental stressors as a driver of the trait composition of benthic macroinvertebrate assemblages in polluted Iberian rivers

ABSTRACT We used the trait composition of macroinvertebrate communities to identify the effects of pesticides and multiple stressors associated with urban land use at different sites of four rivers in Spain. Several physical and chemical stressors (high metal pollution, nutrients, elevated temperature and flow alterations) affected the urban sites. The occurrence of multiple stressors influenced aquatic assemblages at 50% of the sites. We hypothesized that the trait composition of macroinvertebrate assemblages would reflect the strategies that the assemblages used to cope with the respective environmental stressors. We used RLQ and fourth corner analysis to address the relationship between stressors and the trait composition of benthic macroinvertebrates. We found a statistically significant relationship between the trait composition and the exposure of assemblages to environmental stressors. The first RLQ dimension, which explained most of the variability, clearly separated sites according to the stressors. Urban‐related stressors selected taxa that were mainly plurivoltine and fed on deposits. In contrast, pesticide impacted sites selected taxa with high levels of egg protection (better egg survival), indicating a potentially higher risk for egg mortality. Moreover, the trait diversity of assemblages at urban sites was low compared to that observed in pesticide impacted sites, suggesting the homogenization of assemblages in urban areas. HighlightsEffects of stressors at urban and pesticides impacted Iberian rivers were studied.Urban sites were impacted by multiple stressors.Trait composition of assemblages significantly changed with stressors.Trait diversity was lower at urban sites indicating functional homogenization.

Chapter 3 - Prioritization: Selection of Environmentally Occurring Pharmaceuticals to Be Monitored

Abstract Due to increasing contamination of the natural environment by a variety of anthropogenic chemical compounds, which are introduced into the environment in volumes reaching hundred million tons per year, it is evident that risk assessment and prioritization of them must be performed. For the majority of this compounds acute and especially, long-term chronic effects on both human health and ecosystems are still unknown. Considering environmental risk assessments (ERA), the acute toxicity data combined with measure of predicted environmental concentration are the most common tool for estimation of risk. Due to their intrinsic biological activity and their worldwide presence in natural environments, pharmaceutical compounds are one of the chemical compounds that are gaining a lot of attention from the scientific community in recent years. Moreover, their adverse effects on ecosystem have already been proven, mostly in terms of endocrine disruption. Still, for majority of pharmaceuticals, more data of their properties and effects are needed. In this chapter, we give an overview of (a) general aspects of prioritization for purposes of risk assessment and regulation, (b) ERA for pharmaceuticals as proposed by European Medicines Evaluation Agency, and (c) selected prioritization schemes for pharmaceuticals.

Pollutants of Emerging Concern in Rivers of Catalonia: Occurrence, Fate, and Risk

The present chapter provides a review of the occurrence, fate, and risk associated to different families or emerging and priority organic micropollutants in the rivers of Catalonia. Compounds belonging to diverse groups such as industrial compounds, perfluoroalkyl substances, pesticides, halogenated flame retardants, pharmaceuticals and hormones, personal care products, and illegal drugs, as well as their transformation products, are examined. Both emission levels from sewage systems and those found at the receiving water bodies are compared. Potential fate and transformation of the parent compounds is taken into consideration. Finally their environmental risk in terms of the associated ecotoxicity with respect to three trophic levels (Daphnia, algae, and fish) as recommended by the WFD is assessed. This prioritization exercise allows identifying those micropollutants that are more relevant in Catalonian Rivers.

Risk assessment and prioritization of pollutants in continental Mediterranean waters based on hazard quotients

The input of chemical pollutants into the aquatic environment is growing but their potential adverse effects on the ecosystem still remain largely unknown. Therefore the development of appropriate risk assessment procedures capable to provide a prioritization of potential pollutants becomes necessary. Here we identify priority compounds specific to Mediterranean rivers and compare them to those found in other rivers worldwide. To this purpose hazard quotients (HQ) defined as the ratio of measured environmental concentration (MEC) to predicted non effect concentration (PNEC) referred to different trophic levels were calculated for different compounds selected from different existing prioritization schemes, as well as 15 priority substances identified under the Water Framework Directive (WFD) and compared for cases of Mediterranean vs. North European and USA rivers. [Contrib Sci 10:125-134 (2014)]

Contaminants of Emerging Concern in Mediterranean Watersheds

The present chapter provides a general perspective on the occurrence, ecotoxicological risk, and prioritization of emerging and classical contaminants in Mediterranean river basins with special focus on the Iberian Peninsula as representative case, in the light of the results recently obtained. Risk assessment and prioritization criteria based on ecotoxicological risk with respect to different trophic levels are explained and applied to the Mediterranean basins studied. This enables to rank contaminants according to their ecotoxic risk and to quantify their joint effect as a mixture on a river site.

Effects of Emerging Contaminants on Biodiversity, Community Structure, and Adaptation of River Biota

Most river ecosystems are under the joint effects of co-occurring stressors, and attributing the mechanisms by which multiple stressors interact and produce individual and combined effects can be highly complex. This chapter describes the structural and functional responses of the biological communities (biofilms and macroinvertebrates) to different chemical stressors with a special attention to the presence of emerging compounds that become more frequently in the list of co-occurring stressors in rivers. The suitability of different methods (i.e., toxic units and statistical tools) to determine toxicological risk and to establish potential causality of effects on communities has been discussed using Mediterranean basins from the SCARCE project as case study basins.