Environmental quality of transitional waters: the lagoon of Venice case study

The health status of European aquatic environments, including transitional waters such as coastal lagoons, is regulated by the Water Framework Directive (WFD), which requires the classification of the water bodies' environmental quality and the achievement of a good ecological status by 2015. In the Venice lagoon, a transitional water body located in the northeastern part of Italy, the achievement of a good ecological status is hampered by several anthropogenic and natural pressures, such as sediment and water chemical contamination, and sediment erosion. In order to evaluate the lagoon's environmental quality according to the WFD (i.e. 5 quality classes, from High to Bad), an integrated Weight-of-Evidence methodology was developed and applied to classify the quality of the lagoon water bodies, integrating biological, physicochemical, chemical, ecotoxicological, and hydromorphological data (i.e. Lines of Evidence, LOE). The quality assessment was carried out in two lagoon habitat typologies (previously defined on the basis of morphological, sediment, and hydrodynamic characteristics) which were selected taking into account the ecological gradient from sea to land, and the differences in anthropogenic pressure and contamination levels. The LOE classification was carried out by using indicators scored by comparing site specific conditions to reference conditions measured in lagoon reference sites, or provided by local, national or European regulations (e.g. Environmental Quality Standards, EQS, for chemicals). Finally, the overall quality status for each water body was calculated by a probabilistic approach, i.e. by reporting the final result as the frequency distribution of quality classes. The developed procedure was applied by using data and information concerning selected LOE and collected from monitoring programs and research studies carried out in the last 15 years in the lagoon of Venice. A set of sampling stations characterized by spatially and temporally coherent information for each LOE was selected, and among these stations, potential reference sites for each water body typology were identified. The quality assessment highlighted that there are specific lagoon areas, especially those located near the industrially developed area, which are highly affected by anthropogenic activities, and that chemical contamination is one of the main pressures affecting ecological status (e.g. macro-benthonic biodiversity) in the Venice lagoon. The integrated quality assessment procedure that was developed provided a new tool supporting decision making, as well as lagoon assessment and management

Modelling ecological and human exposure to POPs in Venice lagoon. Part I - Application of MERLIN-Expo tool for integrated exposure assessment

Industrial and urban emissions over several decades left a legacy of contamination by persistent organic pollutants in the sediments of Venice lagoon (Italy), which might still represent a hazard for the health of ecosystems and population. A new modelling tool for integrated exposure assessment, MERLIN-Expo, was applied to simulate integrated ecological and human exposure to PCBs and dioxins. MERLIN-Expo library provides a set of environmental fate models that can be easily combined to create several scenarios, and coupled to a human intake and a physiologically-based pharmaco-kinetic (PBPK) model to simulate human internal exposure. The Phytoplankton, Invertebrate and Fish models implemented in MERLIN-Expo library were combined to create an aquatic food web and to dynamically simulate bioaccumulation and biomagnification of dioxins and PCBs. Concentrations of PCB and dioxins in water, reconstructed from concentrations in dated sediment cores, were used as time-series inputs to run long term simulations. Estimated concentrations in edible aquatic species were used to estimate daily human intake through the consumption of local seafood. Finally, the application of the PBPK model allowed to explore the accumulation of 2,3,7,8-TCDD and PCB126 in human tissues for several decades. Simulated chemical concentrations in biota were evaluated against monitoring data for four aquatic species, finding an appreciable agreement, with some differences depending on the species and target chemicals. Estimated chemical concentrations in blood were compared to real human biomonitoring data measured in adult men. Despite several assumptions included in the assessment framework, simulated concentrations resulted close to measured data (the same order of magnitude or one order of difference). The results allowed performing a preliminary ecological and human health risk assessment for the selected chemicals by evaluating the exposure estimates against benchmark values available in literature. The study provided useful insights for supporting the verification of MERLIN-Expo in a real complex exposure scenario. (C) 2016 Elsevier B.V. All rights reserved

Modelling the exposure to chemicals for risk assessment: a comprehensive library of multimedia and PBPK models for integration, prediction, uncertainty and sensitivity analysis - the MERLIN-Expo tool

MERLIN-Expo is a library of models that was developed in the frame of the FP7 EU project 4FUN in order to provide an integrated assessment tool for state-of-the-art exposure assessment for environment, biota and humans, allowing the detection of scientific uncertainties at each step of the exposure process. This paper describes the main features of theMERLIN-Expo tool. The main challenges in exposure modelling that MERLIN-Expo has tackled are: (i) the integration of multimedia (MM) models simulating the fate of chemicals in environmental media, and of physiologically based pharmacokinetic (PBPK) models simulating the fate of chemicals in human body. MERLIN-Expo thus allows the determination of internal effective chemical concentrations; (ii) the incorporation of a set of functionalities for uncertainty/sensitivity analysis, from screening to variance-based approaches. The availability of such tools for uncertainty and sensitivity analysis aimed to facilitate the incorporation of such issues in future decision making; (iii) the integration of human and wildlife biota targets with common fate modelling in the environment.MERLIN-Expo is composed of a library of fate models dedicated to non biological receptor media (surface waters, soils, outdoor air), biological media of concern for humans (several cultivated crops, mammals, milk, fish), as well as wildlife biota (primary producers in rivers, invertebrates, fish) and humans. These models can be linked together to create flexible scenarios relevant for both human and wildlife biota exposure. Standardized documentation for each model and training material were prepared to support an accurate use of the tool by end-users. One of the objectives of the 4FUN project was also to increase the confidence in the applicability of the MERLIN-Expo tool through targeted realistic case studies. In particular, we aimed at demonstrating the feasibility of building complex realistic exposure scenarios and the accuracy of the modelling predictions through a comparison with actual measurements. (C) 2016 Elsevier B.V. All rights reserved