•The food web of the largest Italian river is modelled for the first time with AQUATOX.•We used the model to assess direct and indirect effects of two chemicals on biota.•The response to chemical ...discharge depends on the organism position in the food web.•Biota responses to chemicals are poorly correlated with lab-estimated direct toxicity.•The lack of biomonitoring data to develop river food web models remains a challenge.
Ecological modelling has the potential to increase the realism of chemical risk assessment for better informed risk management and decision making meeting the protection goals and requirements of the EU's chemicals- and water-related regulations. We developed a food web model of the final lowland section of the longest Italian river (Po) to assess the importance of ecological interactions in setting protective thresholds for river ecosystems exposed to chemicals discharged via wastewater. An integrated 14 compartment model was setup using AQUATOX 3.1, providing a dynamic, quantitative representation of the main functional groups in the food web. To our knowledge, this is the first time that the functioning of the Po ecosystem is quantitatively described. The model was calibrated against observations of biomass density of riverine biota, as typically available for a large lowland river in Europe. The role of ecological interactions on the response of the modelled organisms to chemical exposure was tested on realistic and hypothetical exposure scenarios for two compounds contained in home and personal care products: the anionic surfactant linear alkylbenzene sulphonate and the antimicrobial triclosan. At realistic exposure concentrations the model showed no significant effect compared to control simulations. At hypothetical higher exposure, effects resulting from complex ecosystem-scale interactions emerge. Depending on the organism's position in the food web, indirect effects due to ecological interactions can either amplify or mitigate the effect of direct toxicity. Model results indicate that organisms’ responses to chemicals in real ecosystems is poorly correlated to their direct toxicity (i.e. measured by L/ECX values) for a range of simulated exposure, including concentrations equal to the reported PNEC values. AQUATOX is a useful tool to investigate the relative importance of direct toxicity and ecological interactions, but at this stage it is difficult to use it for prospective chemical risk assessment, given the underlying model uncertainties and the practical limitations of field scale evaluations. An improvement of the quantitative monitoring of feeding preferences and abundance over time of the most representative species within each functional group would be of great help to refine the model parameterisation and calibration. Nonetheless, the development of river ecosystem model scenarios is a stepping stone towards the incorporation of ecological modelling in risk assessment. When extensively tested on different scenarios AQUATOX provides a useful platform, which can be linked to mechanistic effect models as long as this component can be evaluated in controlled settings (i.e. laboratory or mesocosm scale).
Unpleasant odors are a major cause of public complaints concerning air quality and represent a growing social problem in industrialized countries. However, the assessment of odor pollution is still ...regarded as a difficult task, because olfactory nuisance can be caused by many different chemical compounds, often found in hard-to-detect concentrations, and the perception of odors is influenced by subjective thresholds; moreover, the impact of odor sources on air quality is mediated by complex atmospheric dispersion processes. The development of standardized assessment approaches to odor pollution and proper international regulatory tools are urgently needed. In particular, comparisons of the methodologies commonly used nowadays to assess odor impacts on air quality are required. Here, we assess the olfactory nuisance caused by an anaerobic treatment plant for municipal solid waste by means of two alternative techniques: the field inspection procedure and the atmospheric dispersion model CALPUFF. Our goal was to compare rigorously their estimates of odor nuisance, both qualitatively (spatial extent of odor impact) and quantitatively (intensity of odor nuisance). To define the impact of odors, we referred to the German standards, based on the frequency of odor episodes in terms of odor hours. We report a satisfying, although not perfect agreement between the estimates provided by the two techniques. For example, they assessed similar spatial extents of odor pollution, but different frequencies of odor episodes in locations where the odor nuisance was highest. The comparison highlights strengths and weaknesses for both approaches. CALPUFF is a cheaper methodology which can be used predictively, but fugitive emissions are difficult to model reliably, because of uncertainty regarding timing, location and emission rate. Field inspection takes into account the role of human perception, but unlike the model it does not always characterize precisely the extent of the odor nuisance caused by a single source when other odors are present, because only the most unpleasant odor is reported. We conclude that these two assessment methods provide reasonable estimates of odor nuisance.
► We compare methods to assess odor pollution from an anaerobic digestion plant for MSW. ► We applied the atmospheric dispersion model CALPUFF and the Odor Field Inspection. ► They were compared quantitatively and qualitatively over the same area for 6 months. ► The methods assessed similar spatial extents of nuisance in terms of odor frequency. ► The two methods provide complementary information about odor nuisance.
The inhalation of pesticide in air is of particular concern for people living in close contact with intensive agricultural activities. This study aims to develop an integrated modelling methodology ...to assess whether pesticides pose a risk to the health of people living near vineyards, and apply this methodology in the world-renowned Prosecco DOCG (Italian label for protection of origin and geographical indication of wines) region. A sample field in Bigolino di Valdobbiadene (North-Eastern Italy) was selected to perform the pesticide fate modellization and the consequent inhalation risk assessment for people living in the area. The modellization accounts for the direct pesticide loss during the treatment of vineyards and for the volatilization from soil after the end of the treatment. A fugacity model was used to assess the volatilization flux from soil. The Gaussian puff air dispersion model CALPUFF was employed to assess the airborne concentration of the emitted pesticide over the simulation domain. The subsequent risk assessment integrates the HArmonised environmental Indicators for pesticide Risk (HAIR) and US-EPA guidelines. In this case study the modelled situation turned to be safe from the point of view of human health in the case of non-carcinogenic compounds, and additional improvements were suggested to further mitigate the effect of the most critical compound.
•New approach for the evaluation of pesticide inhalation exposure nearby vineyards.•Volatilization from soil modelled with a fugacity model “Soil”.•Dispersion of pesticide modelled with CALPUFF.•No acute and chronic risk identified for residents.•Application of drift reduction technique has been investigated.
The Mediterranean region is of fundamental importance to Europe given its strategic position. The responsibility for its overall ecosystem integrity is shared by European Union Member States (EU-MS) ...and other Mediterranean countries. A juxtaposition of overlapping governance instruments occurred recently in the region, with the implementation of both the Marine Strategy Framework Directive (MSFD) for EU-MS and the Ecosystem Approach Strategy (ECAP) for all Mediterranean countries, including EU-MS. Both MSFD and ECAP are structured around vision-driven processes to achieve Good Environmental Status and a Healthy Environment, respectively. These processes have clear ecosystem-based, integrated policy objectives to guarantee the preservation and integrity of Mediterranean marine ecosystem goods and services. However, adoption of these instruments, especially those related to the new EU-MS directives on marine policy, could result in a governance gap in addition to the well-known economic gap between the EU and the non-EU political blocs. We identify two complementary requirements for effective implementation of both MSFD and ECAP that could work together to reduce this gap, to ensure a better alignment between MSFD and ECAP and better planning for stakeholder engagement. These are key issues for the future success of these instruments in a Mediterranean region where discrepancies between societal and ecological objectives may pose a challenge to these processes.
Over the past decades, per- and polyfluoroalkyl substances (PFASs) found in environmental matrices worldwide have raised concerns due to their toxicity, ubiquity and persistence. A widespread ...pollution of groundwater and surface waters caused by PFASs in Northern Italy has been recently discovered, becoming a major environmental issue, also because the exact risk for humans and nature posed by this contamination is unclear. Here, the Po River in Northern Italy was selected as a study area to assess the ecological risk posed by perfluoroalkyl acids (PFAAs), a class of PFASs, considering the noticeable concentration of various PFAAs detected in the Po waters over the past years. Moreover, the Po has a large environmental and socio-economic importance: it is the largest Italian river and drains a densely inhabited, intensely cultivated and heavily industrialized watershed. Predicted no-effect concentrations (PNECs) were derived using two regulated methodologies, assessment factors (AFs) and species sensitivity distribution (SSD), which rely on published ecotoxicological laboratory tests. Results were compared to those of a novel methodology using the mechanistic ecosystem model AQUATOX to compute PNECs in an ecologically-sound manner, i.e. considering physical, chemical, biological and ecological processes in the river. The model was used to quantify how the biomasses of the modelled taxa in the river food web deviated from natural conditions due to varying inputs of the chemicals. PNEC for each chemical was defined as the lowest chemical concentration causing a non-negligible yearly biomass loss for a simulated taxon with respect to a control simulation. The investigated PFAAs were Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS) as long-chained compounds, and Perfluorobutanoic acid (PFBA) and Perfluorobutanesulfonic acid (PFBS) as short-chained homologues. Two emerging contaminants, Linear Alkylbenzene Sulfonate (LAS) and triclosan, were also studied to assess the performance of the three methodologies for chemicals whose ecotoxicology and environmental fate are well-studied. The most precautionary approach was the use of AFs generally followed by SSD and then AQUATOX, except for PFOS, for which AQUATOX yielded a much lower PNEC compared to the other approaches since, unlike the other two methodologies, it explicitly simulates sublethal toxicity and indirect ecological effects. Our findings highlight that neglecting the role of ecological processes when extrapolating from laboratory tests to ecosystems can result in under-protective threshold concentrations for chemicals. Ecosystem models can complement existing laboratory-based methodologies, and the use of multiple methods for deriving PNECs can help to clarify uncertainty in ecological risk estimates.
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•Multiple methods for PNEC estimation can ensure higher confidence in results.•Assessment factor is usually the most protective ecological risk assessment method.•Ecological models allow insightful extrapolation from single-species to ecosystems.•Ignoring sublethal toxicity and ecological relationships can underestimate risk.•The AQUATOX-derived PNEC for PFOS is 3.6% of the currently accepted freshwater EQS.
The loss of coastal habitats is a widespread problem in Europe. To protect the intertidal salt marshes of the lagoon of Venice from the erosion due to natural and human causes which is diffusely and ...intensely impacting them, the European Commission has funded the demonstrative project LIFE VIMINE. LIFE VIMINE aims to protect the most interior, hard-to-access salt marshes in the northern lagoon of Venice through an integrated approach, whose core is the prevention of erosion through numerous, small but spatially-diffuse soil-bioengineering protections works, mainly placed through semi-manual labour and with low impact on the environment and the landscape. The effectiveness of protection works in the long term is ensured through routine, temporally-continuous and spatially-diffuse actions of monitoring and maintenance. This method contrasts the common approach to managing hydraulic risk and erosion in Italy which is based on large, one-off and irreversible protection actions. The sustainability of the LIFE VIMINE approach is ensured by the participatory involvement of stakeholders and the recognition that protecting salt marshes means defending the benefits they provide to society through their ecological functions, as well as protecting the jobs linked to the existence or conservation of this habitat.
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•Short-chain PFAAs can strongly bioaccumulate in food crops but are not regulated.•We explored the role of polluted soil and irrigation water as PFAAs delivery media.•In red chicory, ...PFAA chain length strongly correlated with root and shoot BCFs.•Concentrations of PFAAs were measured by soil depth and compared to laboratory Kds.•Contaminated irrigation water use led to higher PFAA accumulation in chicory shoots.
Perfluoroalkyl acids (PFAAs), particularly short-chained ones, have high potential for crop uptake, posing a threat to human health in contaminated areas. There is a scarcity of studies using contaminated water as the medium for PFAAs delivery to crops, and a lack of data on the partitioning of PFAA mixtures in growing media. In this context, a controlled experimental study was carried out in a greenhouse to investigate the uptake of a PFAA mixture into red chicory, a typical crop from a major PFAA contamination hot-spot in northern Italy, under treatments with environmentally relevant concentrations in spiked irrigation water and soil, separately and simultaneously. To our knowledge, this is the first study involving multiple exposure media and laboratory adsorption/desorption batch tests as a way of assessing the decrease in the bioavailability of PFAAs from soil. Exposure concentrations for each of the 9 utilized PFAAs were 0, 1, 10 and 80 µg/L in irrigation water and 0, 100 and 200 ng/gdw in soil, combined into 12 treatments. The highest bioaccumulation was measured for PFBA in roots (maximum of 43 µg/gdw), followed by leaves and heads of the chicory plants in all treatments, with the concentrations exponentially decreasing with an increasing PFAA chain length in all plant compartments. The use of irrigation water as the delivery medium increased the transport of PFAAs to the aerial chicory parts, long-chain substances in particular. Additionally, the distribution of PFAAs in the soil was assessed by depth and compared with laboratory measured soil-water equilibrium partition coefficients, revealing only partial dependency of PFAAs bioavailability on the adsorption in soil.
Short-chain perfluoroalkyl acids (PFAAs) have shown a high potential for plant (crop) uptake, making them possibly significant contributors to the total dietary exposure to PFAAs. The plant uptake of ...PFAAs is a complex process that needs better characterization, as it does not only depend on perfluoroalkyl chain length, but also on their polar terminal group, on the plant species and the exposure media. Here, a plant uptake study with nine perfluoroalkyl acids (PFAAs) was carried out under the hydroponic (soilless) exposure conditions. Red chicory was grown in a nutrient solution, spiked with PFAAs mixture at three different concentrations (i.e. 62.5, 125 and 250 μg/L), in order to extend the range of levels tested and reported in the literature so far. Bioaccumulation metrics and transpiration stream concentration factors (TSCFs) were employed for the plant uptake characterization and consequent comparison with the results of soil uptake experiment we previously performed with the same crop. The results showed that calculated root concentration factors (RCFs) increase with PFAA chain length, while the opposite chain length dependence was present for shoots. Plants from two treatments with the highest PFAAs concentrations manifested physiological changes (discoloration, inhibited roots and leaves growth), despite of the used exposure concentrations being much lower than previously published phytotoxicity thresholds. A comparison among RCFs and TSCFs derived from hydroponic and from the soil experiment has emphasized their different magnitudes and PFAAs chain length dependence patterns. They could not be ascribed only to soil sorption as a process decreasing PFAAs bioavailability for plants, but also to developmental differences between the root systems formed in soil and in nutrient solution and to the potential competitive PFAAs sorption to roots in hydroponics. The interchangeable use of bioaccumulation and translocation parameters derived in hydroponic and soil systems would lead to erroneous conclusions and plant uptake predictions.
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•Bioaccumulation of PFAAs in crops depends on many factors (e.g. growth media).•The root uptake of nine PFAAs into red chicory in soilless, hydroponic experiment.•Bioaccumulation chain-length patterns and comparison with the growth in soil.•Manifested visible phytotoxic effects in concentrations ≥125 μg/L of each PFAA.•Bioavailability does not depend only on in-soil sorption, but also on roots development.
The risk of air quality degradation is of considerable concern particularly for those airports that are located near urban areas. The ability to quantitatively predict the effects of air pollutants ...originated by airport operations is important for assessing air quality and the related impacts on human health. Current emission regulations have focused on local air quality in the proximity of airports. However, an integrated study should consider the effects of meteorological events, at both regional and local level, that can affect the dispersion and the deposition of exhausts. Rigorous scientific studies and extensive experimental data could contribute to the analysis of the impacts of airports expansion plans.
This paper is focused on the analysis of the effects of meteorology on aircraft emission for the Marco Polo Airport in Venice. This is the most important international airport in the eastern part of the Po’ Valley, one of the most polluted area in Europe. Air pollution is exacerbated by meteorology that is a combination of large and local scale effects that do not allow significant dispersion. Moreover, the airport is located near Venice, a city of noteworthy cultural and architectural relevance, and nearby the lagoon that hosts several areas of outstanding ecological importance at European level (Natura 2000 sites).
Dispersion and deposit of the main aircraft exhausts (NOx, HC and CO) have been evaluated by using a Lagrangian particle model. Spatial and temporal aircraft exhaust dispersion has been analyzed for LTO cycle. Aircraft taxiing resulted to be the most impacting aircraft operation especially for the airport working area and its surroundings, however occasionally peaks may be observed even at high altitudes when cruise mode starts. Mixing height can affect concentrations more significantly than the concentrations in the exhausts themselves. An increase of HC and CO concentrations (15–50%) has been observed during specific meteorological events.
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•A Lagrangian particle model was used to study the Venice Airport air quality impact.•Meteorology impact on aircraft emission dispersion and deposition was evaluated.•Emission sources geometry and their representation have been discussed.•The dispersion maps and concentrations of the main aircraft exhausts were discussed.•Exhausts impact in relation to the most risky target was discussed.
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