Are Geotextiles Silent Contributors of Ultrashort Chain PFASs to the Environment?

We investigated the presence of per- and poly fluoroalkyl substances (PFASs) in woven and nonwoven polypropylene geotextiles and four nonwoven polyester geotextiles commonly used in modern geosynthetic composite lining systems for waste containment facilities such as landfills. Targeted analysis for 23 environmentally significant PFAS molecules and methods for examining "PFAS total" concentrations were utilized to assess their occurrence in geotextiles. This analysis showed that most geotextile specimens evaluated in the current investigation contained the ultrashort chain PFAS compound pentafluoropropionic acid (PFPrA). While the concentrations ranged from nondetectable to 10.84 µg/g, the average measured concentrations of PFPrA were higher in polypropylene than in polyester geotextiles. "PFAS total" parameters comprising total fluorine (TF) and total oxidizable precursors (TOPs) indicate that no significant precursor mass nor untargeted intermediates were present in geotextiles. Therefore, this study identified geotextiles as a possible source of ultrashort PFASs in engineered lined waste containment facilities, which may contribute to the overall PFAS total concentrations in leachates or liquors they are in contact with. The findings reported for the first time herein may lead to further implications on the fate and migration of PFASs in geosynthetic composite liners, as previously unidentified concentrations, particularly of ultrashort-chain PFASs, may impact the extent of PFAS migration through and attenuation by constituents of geosynthetic composite liner systems. Given the widespread use of geotextiles in various engineering activities, these findings may have other unknown impacts. The significance of these findings needs to be further elucidated by more extensive studies with larger geotextile sample sizes to allow broader, generalized conclusions to be drawn.

Migration patterns of heavy metals from solid waste stockpile soils by native plants for ecological restoration in arid and semi-arid regions of Northwest China.

Ecological remediation with native plants is the main measure to control the pollution of solid waste in Northwest China. However, the heavy metal transport characteristics of these native plants are still unidentified. This study analyzed the distribution of 16 heavy metals in native plants in the desulfurization gypsum yard (DGY), the gangue yard (GY) and the fly ash yard (FAY). The results showed that the soil contained many heavy metals in high concentrations. For instance, As concentrations were comparable to the global soil background values, whereas Cr and Mn concentrations in the area were 2-3 times greater than the global soil background values. The content of heavy metals in the plant root system increased first, then decreased as the distance from the yard increased. Ni, Pb, and Cd migrated well in Artemisia frigida Willd and Artemisia sieversiana Ehrhart ex Willd, with A. sieversiana showing a particularly strong migration in GY. A. sieversiana, on the other hand, was more successful at migrating Cd at DGY and had a similar capability for Mg migration in all three locations. Festuca rubra L was potentially suitable for planting in GY for Ni removal. In conclusion, the migration patterns of different heavy metals were not alike for plants in the three landfills. The results provided a basis for plant selection for ecological restoration in arid and semi-arid regions.

Social cost--benefit analysis of solid waste management options with application to Mumbai, India.

Managing solid waste continues to be an environmental, technical and economic challenge, especially for developing countries. Though these countries' urban local bodies (ULBs) are moving up the waste management hierarchy, most waste is still openly dumped. One key reason for this choice is the non-accounting of (a) social costs associated with open dumping (OD) and (b) direct/indirect benefits of other options. The current study conducts a complete social cost-benefit analysis (SCBA) comparing OD to sanitary landfilling, composting, bio-methanation, incineration and gasification alternatives. The study finds that when only private costs/benefits are considered, a mix of OD and sanitary landfills is preferred; however, when external costs/benefits are factored in, the mix shifts towards alternatives like incineration and gasification. These learnings from the SCBA are then applied to Mumbai, which generates 9000 tonnes of waste daily. To determine the optimal mix for Mumbai ULB, a constrained optimization exercise is carried out considering the technical feasibility of the alternatives and the ULB's capital budget. The study finds that with the current practice of OD, the net present value (NPV) of the social costs over a 30-year horizon will be over US$ 6-9 billion. However, even if one-fifth of the ULB's capital budget is allocated towards other waste management alternatives, the mix would shift towards sophisticated technologies and the NPV of social costs would reduce to around half that amount.

Detection and extinguishment approaches for municipal solid waste landfill fires: A mini review.

Municipal solid waste (MSW) management is getting more attention in the present scenario. Even though various technologies like incineration, gasification, pyrolysis and waste-to-energy plants have been developed, landfills are still the major disposal option for MSW management. MSW at landfill creates issues that are highlighted at a global level like the fire at Deonar dumping site in Mumbai, India was visible and captured by the space satellites, leading to environmental pollution. Detection and extinguishment of landfill fires at surface and sub-surface in their early stages are the major concern. Thermal imaging camera can be used to know solar radiation effect by identifying the hotspots during the day and the night time for understanding aerobic degradation effect on the surface fire. Sub-surface gas concentrations and its combinations affecting the temperature gradient can be studied for a better understanding of sub-surface fires in their early stages. The use of class 'A' foams with water, which reduces the surface tension of water, can be carried out for landfill fire extinguishment. The application of water in the form of water fog will extract a large amount of heat and block the availability of oxygen for the fire. This mini review presents the sources of fuel, heat, oxidant for landfill fire and its development process, associated pollution on air, water, land and human health due to landfill fire and methods for its extinguishment possibilities.

Synergistic effects of vegetation and microorganisms on enhancing of biodegradation of landfill gas.

The uncontrolled release of landfill gas represents a significant hazard to both human health and ecological well-being. However, the synergistic interactions of vegetation and microorganisms can effectively mitigate this threat by removing pollutants. This study provides a comprehensive review of the current status of controlling landfill gas pollution through the process of revegetation in landfill cover. Our survey has identified several common indicator plants such as Setaria faberi, Sarcandra glabra, and Fraxinus chinensis that grow in covered landfill soil. Local herbaceous plants possess stronger tolerance, making them ideal for the establishment of closed landfills. Moreover, numerous studies have demonstrated that cover plants significantly promote methane oxidation, with an average oxidation capacity twice that of bare soil. Furthermore, we have conducted an analysis of the interrelationships among vegetation, landfill gas, landfill cover soil, and microorganisms, thereby providing a detailed understanding of the potential for vegetation restoration in landfill cover. Additionally, we have summarized studies on the rhizosphere effect and have deduced the mechanisms through which plants biodegrade methane and typical non-methane pollutants. Finally, we have suggested future research directions to better control landfill gas using vegetation and microorganisms.

Neighborhood infrastructure-related risk factors and non-communicable diseases: a systematic meta-review.

BACKGROUND: With rapid urbanization, the urban environment, especially the neighborhood environment, has received increasing global attention. However, a comprehensive overview of the association between neighborhood risk factors and human health remains unclear due to the large number of neighborhood risk factor-human health outcome pairs. METHOD: On the basis of a whole year of panel discussions, we first obtained a list of 5 neighborhood domains, containing 33 uniformly defined neighborhood risk factors. We only focused on neighborhood infrastructure-related risk factors with the potential for spatial interventions through urban design tools. Subsequently, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic meta-review of 17 infrastructure-related risk factors of the 33 neighborhood risk factors (e.g., green and blue spaces, proximity to major roads, and proximity to landfills) was conducted using four databases, Web of Science, PubMed, OVID, and Cochrane Library, from January 2000 to May 2021, and corresponding evidence for non-communicable diseases (NCDs) was synthesized. The review quality was assessed according to the A MeaSurement Tool to Assess Systematic Reviews (AMSTAR) standard. RESULTS: Thirty-three moderate-and high-quality reviews were included in the analysis. Thirteen major NCD outcomes were found to be associated with neighborhood infrastructure-related risk factors. Green and blue spaces or walkability had protective effects on human health. In contrast, proximity to major roads, industry, and landfills posed serious threats to human health. Inconsistent results were obtained for four neighborhood risk factors: facilities for physical and leisure activities, accessibility to infrastructure providing unhealthy food, proximity to industry, and proximity to major roads. CONCLUSIONS: This meta-review presents a comprehensive overview of the effects of neighborhood infrastructure-related risk factors on NCDs. Findings on the risk factors with strong evidence can help improve healthy city guidelines and promote urban sustainability. In addition, the unknown or uncertain association between many neighborhood risk factors and certain types of NCDs requires further research.

Effects of perfluoroalkyl substances (PFAS) on antioxidant depletion from a high-density polyethylene geomembrane.

To safely contain Per-and Polyfluoroalkyl substances (PFAS) in municipal solid waste landfills and contaminated soil monofills, it is necessary to understand how these substances interact with components of engineered systems designed to contain them. This paper examines the interaction between one of the most critical components of the system: a high-density polyethylene (HDPE) geomembrane. The same geomembrane is immersed in PFAS solution and synthetic municipal solid waste leachate containing PFAS for 2.5 years, and the effects of PFAS on antioxidant depletion time is examined. The geomembrane is incubated in ovens at 85-40 °C to obtain data for Arrhenius predictions at typical landfill temperatures. When exposed to PFAS solution alone, the antioxidant depletion times are smaller than when the same geomembrane is immersed in synthetic municipal solid waste leachate alone. The combination of the two has a synergistic effect which leads to an even greater reduction in antioxidant depletion time for this geomembrane, with results showing a 68% decrease in predicted antioxidant depletion time at a typical landfill temperature of 35 °C when PFAS is present in leachate. This study highlights the need to consider the potential impact of PFAS on the service life of geomembranes used to contain them.

Insights into sustainable resource and energy recovery from leachate towards emission mitigation for environmental management: A critical approach.

The exponential generation of municipal solid waste (MSW) and landfill disposal without any treatment has increased the continuous generation of landfill leachate. Improper MSW and leachate management are contributing to environmental degradation and water and soil pollution, which must be treated. Numerous works have been conducted on leachate treatments for energy and resource recovery. This review presents a comprehensive study of leachate management in which different treatment methods are discussed to analyze the suitability of processes that can be employed to treat leachate efficiently. Further, the characteristics of leachate are examined as properties of leachate may be varied depending upon the region. Still, several challenges related to leachate management and its treatments are discussed in this study. An integrated system could be a better option for treating leachate because it contains large amounts of organic and inorganic compounds. Proper leachate management would help to recover energy and value-added products (metals).

Classification of pores, water diffusivity and penetration characteristics of waste materials, and role of water as electron carrier in landfills: A review.

Coupling of biogeochemical processes occurs between different waste components and waste layers during decomposition of wastes materials deposited in landfills by mechanisms similar to those occurring in marine sediments (i.e., sediment batteries). In landfills, moisture serves as a medium for transfer of electrons and protons under anaerobic conditions for decomposition reactions to proceed spontaneously, although some reactions occur very slowly. However, the role of moisture in landfills in view of pore sizes and pore size distributions, time dependent changes in pore volumes, heterogeneity of waste layers, and associated impacts on moisture retention and transport characteristics in landfills are not well understood. The moisture transport models developed for granular materials (e.g., soils) are not appropriate to describe the conditions at landfills due compressible and dynamic conditions in landfills. During waste decomposition processes, absorbed water and water of hydration can be transformed to free water and/or become mobilized as liquid or vapor, creating a medium for transfer of electrons and protons between waste components and waste layers. The characteristics of different municipal waste components were compiled and analyzed for pore size, surface energy, and moisture retention and penetration for electron-proton transfer for continuance of decomposition reactions in landfills over time. Categorization of pore sizes appropriate for waste components and a representative water retention curve for conditions in landfills were developed to clarify the terminology and highlight the differences between the landfill conditions and granular materials (e.g., soils) for use of appropriate terminologies. Water saturation profile and water mobility were analyzed by considering water as a transfer medium for carrying electrons and protons for sustaining long-term decomposition reactions.

Impact of temperature on the performance of compost-based landfill biocovers.

Methane (CH4) emissions from landfills are a major contributor to global greenhouse gas emissions. Compost-based biocovers offer a viable approach to reduce CH4 emissions from landfills; however, the effectiveness in climates with varying temperatures is not well understood. The methane removal performances of two compost-based biocover materials (food and yard waste compost) were examined under different temperature conditions using laboratory column experiments. A reactive transport model was used to simulate the experimental results to develop a better quantitative understanding of the effect of temperature on overall methane removal efficiency. As expected, experimental results indicated that the oxidation rate was influenced by temperature, as it was reduced when the temperature decreased from 22 °C to 8 °C. However, some oxidation was observed at a lower temperature, which was confirmed by CO2 concentrations above the initial level and the observed temperatures above the exposure temperature along the height of biocover column. Furthermore, results showed that when the compost-based materials were subjected to 8 °C and then increased to 22 °C, methane oxidation within the material recovered quickly and returned to similar oxidation rates as observed before the temperature was reduced, suggesting that compost-based biocovers may not be affected by cyclic temperature variations when used in colder climates. Methane oxidation capacity was limited by the maximum oxidation rate, the biocover porosity, and the gas saturation profile that affects residence time and overall methane oxidation in the columns. The model results show that the CH4 oxidation rate was reduced by one order of magnitude when the temperature decreased from 22 °C to 8 °C. Therefore, the calculated Q10 values were 4.19 and 5.18 for the food and yard waste compost, respectively. Overall, compost-based landfill biocovers, such as food and yard waste compost, are capable of mitigate CH4 emissions from old and small landfills under different temperature conditions.

Thermal properties of municipal solid waste components and their relative significance for heat retention, conduction, and thermal diffusion in landfills.

Significant amounts of heat can be generated during the initial stages after wastes are deposited in landfills, primarily due to decomposition of food waste. Objectives of this study are to compile, examine and compare thermal properties of municipal solid waste (MSW) components, and liquid and gas phases in MSW landfills and their thermal responses that effect temperature increases in gas and leachate. Specific thermal properties examined include thermal conductivity, thermal diffusivity, and specific heat of waste materials deposited in landfills, liquids (water), and gases present. Compilation of these properties will allow in depth thermal analyses to evaluate heat transfer dynamics in landfills with different waste compositions. Examination of thermal characteristics of MSW components indicate that heat generated during decomposition of waste components would primarily be transferred to liquid (leachate) due to formation of water and gaseous components and their high specific heats. As a result, both the leachate and gases released from a landfill during the initial stages after wastes are deposited and when some oxygen is present as an electron acceptor will be warmer. Except for the metals and construction waste, it is likely that most waste components will have a significant temperature gradient during warming up and cooling off stages due to their low thermal conductivities and low thermal diffusivities. Even when the gas phase is at higher temperatures, it will take long time for waste materials (other than food waste and metals) to come to a uniform temperature during the heat generation (primarily due to decomposition of food waste) in a landfill.

Assessment of potentially toxic metal(loid)s contamination in soil near the industrial landfill and impact on human health: an evaluation of risk.

The generation of solid waste is increasing with each passing day due to rapid urbanization and industrialization and has become a matter of concern for the international community. Leachate leakages from landfills pollute the soil and can potentially harm the human health. In this paper, inductively coupled plasma-optical emission spectrometric studies were employed to assess and analyze the composition of metals (Ba, Cd, Pb, Hg, Cu, Cr and Mn) and metalloid (As) in soil samples. Results of Cr, Mn, Cu, As, Ba, Cd, Pb and Hg from CRM (certified reference material, SRM 2709a) of San Joaquin soil were evaluated and reported in terms of percent recoveries which were in the range of 97.6-102.9% and show outstanding extraction efficiency. Other than copper, where the permitted limit set by the EU is specified as 50-140 mg/kg in soil, the average amount of all the metals in soil was found within the permissible limits provided by WHO, the European Community (EU) and US EPA. Soil contaminated with Hg (PERI = 100) and Cd (PERI = 145.50) posed an ecological risk significantly. Pollution load index (PLI) value is greater than 1, while degree of contamination (Cdeg) value is less than 32 which indicated that the soil is polluted and considerably contaminated with metals and metalloid, respectively. In terms of the average daily dosage (ADD) of soil, children received the highest doses of all metals (ADDing = 1.315 × 10-7 - 2.470 × 10-3 and ADDderm = 9.939 × 10-7 - 5.292 × 10-11), whereas ADDing (1.409 × 10-8 - 2.646 × 10-4) was found greater in adults. For all metals except for Ba, the hazard quotient (HQ) trend in both children and adults was observed to be HQing > HQderm > HQinh of soil. Children who are at the lower edge of cancer risk had a lifetime cancer risk (LCR) of 2.039 × 10-4 for Cr from various paths of soil exposure.

Atmospheric parameters play an important role in driving hydrogen sulphide concentrations in ambient air near waste management centres.

Emissions of odorous compounds are major contributors to public opposition when siting waste management facilities. Thus, it is essential to understand how to minimise the concentration of odour-causing chemicals in ambient air surrounding such facilities. Although the concentration of pollutants in the atmosphere is a function of meteorology, there is limited data on the atmospheric parameters that drive ambient air concentrations of odour-causing substances in settlements near waste management facilities. Here, we analysed how temperature, wind direction, wind speed, atmospheric pressure and humidity impact the concentrations of hydrogen sulphide (H2S) in the ambient air, a potentially toxic chemical and a chief contributor to noxious odours. The relative contribution of each variable was assessed using multivariate statistical analysis applied to an extensive data set of over 7,000 data points collected during 2021. Our results show that all tested atmospheric parameters significantly affected H2S concentrations in ambient air. Wind direction had the greatest impact on H2S concentrations, followed by temperature, humidity, atmospheric pressure and wind speed. Specifically, the concentration of H2S was positively correlated with humidity and atmospheric pressure and had a U-shaped correlation with temperature. Atmospheric variables were able to explain 15% of variation in H2S concentrations (R2 = 15%), indicating the presence of other factors affecting H2S ambient air concentrations. Our study shows that proper consideration of atmospheric parameters, especially wind direction and temperatures, is of uttermost importance when siting waste management facilities. The conclusions are broadly applicable to odorous compounds near waste management facilities, so adverse effects to human health and the environment can be minimised.

Prediction of oxygen distribution in the waste mass from an aeration well in bioreactor landfills.

The key to upgrade the efficiency of aerobic remediation of landfills is to determine the distribution characteristics of oxygen concentration during aerobic ventilation. This study discusses the distribution law of oxygen concentration with time and radial distance based on a single-well aeration test at an old landfill site. The transient analytical solution of the radial oxygen concentration distribution was deduced using the gas continuity equation and approximation of calculus and logarithmic functions. Oxygen concentration data from the field monitoring were compared with the results predicted by the analytical solution. The results indicated that the oxygen concentration initially increased and then decreased with prolonged aeration time. With an increase in radial distance, the oxygen concentration rapidly declined, followed by a gradual decrease. The influence radius of the aeration well increased slightly when the aeration pressure increased from 2 to 20 kPa. The field test data agreed with the analytical solution prediction results, preliminarily verifying the reliability of the oxygen concentration prediction model. Results from this study provide a basis of guidelines for the design, operation and maintenance management of a landfill aerobic restoration project.

Life-cycle assessment approach for municipal solid waste management system of Delhi city.

The life-cycle assessment (LCA) approach with route optimization technique was adopted in the present study to evaluate environmental and economic aspects associated with the prevalent waste management system in Delhi city. With an objective of cost minimization and abating environmental hazards from waste transportation systems, ArcGIS was used to identify the most appropriate route for waste transportation. The study was conducted considering four landfills located at Bawana, Bhalswa, Ghazipur and Okhla present in Delhi city. Landfilling, composting, anaerobic digestion, and recycling methods were analyzed for global warming potential (GWP), eutrophication potential (EP), acidification potential, abiotic resource depletion potential and photochemical oxidation potential parameters using LCA software GaBiPro. The results from the LCA studies for the municipal solid waste management system of Delhi city revealed that transportation emissions and landfilling negatively impact the environment. The effect of recycling rate on the landfilling, composting, anaerobic digestion was also studied using sensitivity analysis. Results of sensitivity analysis depicted that recycling of waste is inversely related to the impact categories. Overall, the results exhibited a detrimental effect of landfilling on the environment in terms of GWP and EP. Further, considering the geospatial analysis, two waste recycling stations are proposed in the vicinity of existing waste management plants to reduce the time and cost of waste transport from the landfills to the waste management plants.

Assessment of in situ properties of municipal solid waste with a large-diameter borehole method.

A Municipal Solid Waste Borehole Assessment (MBA) was developed to assess in situ geotechnical properties of municipal solid waste (MSW) during the boring of gas extraction well construction. A Large-Diameter Borehole Caliper (LDBC) was lowered into the borehole to measure the diameter and record the condition of the wall by time-lapse video photography. The results indicated that the borehole experienced significant radial compression with depth following completion. Radial compressions amounted to approximately 7.5% at 9.14 m, 10% at 21.3 m and 11% at 27.4 m below ground surface. The bulk modulus was estimated by using the captured volumetric strains and reported lateral earth coefficients, and the results showed that it increases with increasing depth. For MSW, the bulk modulus increased up to 13.4 MPa in a linear trend with depth. The unit weights of MSW were obtained using three diameter readings from LDBC, auger barrel outside diameter and outer cutting bit outside diameter. The results showed that the diameter based on outer cutting bit yielded realistic unit weights (5.08-9.68 kN m-3) due to unrealistic calculated saturations by other two assumed diameters. The borehole assessment with LDBC was shown to be an efficient and valuable means for characterising MSW and effectively designing gas extraction wells. The research provided a means to assess the waste mass with accuracy at great depths by directly observing and measuring borehole condition.

Mitigating long-term emissions of landfill aftercare: Preliminary results from experiments combining microbial electrochemical technologies and in situ aeration.

Landfills still represent the main option for waste disposal in many parts of the world. Anyway, they often pose a significant pollution risk and contribute to potential environmental and human health impacts via gaseous and liquid (leachate) emission pathways if not properly managed. Some innovative technologies can help to reduce these emissions, such as in situ aeration and the application of microbial electrochemical technologies (METs). METs are an emerging field that open the possibility to control microbial reactions, enhancing electron flows from electron donors towards electron acceptors. To this end, several materials with different electrochemically-active properties are used, such as electrical conductivity, capacitance, surface electroactivity and charge. The present project named LA-LA-LAND (Landfill electron-Lapping for a LANDscape requalification) was aimed to apply METs to treat leachate-saturated zones in old landfills. A MET prototype was constructed using a granular anode (graphite) and a cylindrical air-cathode (electroactive biochar). The METs were integrated to three identical laboratory-scale landfill bioreactors coupled with the in situ aeration technique, while three control reactors run without MET. The maximum values of current and power density obtained were 0.015 A·m-2 and 0.00035 W·m-2. The influence of the MET system on the organic matter removal was evident in two reactors, where this technology was applied, with respect to the control ones: total organic carbon decreased on average 13%, while it reduced less than 5% in the control reactors. This preliminary experiment pointed out some critical aspects of MET configuration, such as the weakness of the cathode architecture, which was prone to be flooded by leachate, blocking the aeration flux.

Legacy and Emerging Per- and Polyfluoroalkyl Substances: Analytical Techniques, Environmental Fate, and Health Effects.

Due to their unique chemical properties, per- and polyfluoroalkyl substances (PFAS) have been used extensively as industrial surfactants and processing aids. While several types of PFAS have been voluntarily phased out by their manufacturers, these chemicals continue to be of ecological and public health concern due to their persistence in the environment and their presence in living organisms. Moreover, while the compounds referred to as "legacy" PFAS remain in the environment, alternative compounds have emerged as replacements for their legacy predecessors and are now detected in numerous matrices. In this review, we discuss the historical uses of PFAS, recent advances in analytical techniques for analysis of these compounds, and the fate of PFAS in the environment. In addition, we evaluate current biomonitoring studies of human exposure to legacy and emerging PFAS and examine the associations of PFAS exposure with human health impacts, including cancer- and non-cancer-related outcomes. Special focus is given to short-chain perfluoroalkyl acids (PFAAs) and ether-substituted, polyfluoroalkyl alternatives including hexafluoropropylene oxide dimer acid (HFPO-DA; tradename GenX), 4,8-dioxa-3H-perfluorononanoic acid (DONA), and 6:2 chlorinated polyfluoroethersulfonic acid (6:2 Cl-PFESA; tradename F-53B).

Flight altitudes of a soaring bird suggest landfill sites as power line collision hotspots.

Anthropogenic structures are increasingly encroaching wildlife habitats, creating conflicts between humans and animals. Scaling up renewable energy requires new infrastructures such as power lines, that cause high mortality among birds since they act as obstacles to flight and are used for perching and nesting, which can result in collisions or electrocutions. These interactions often endanger wildlife populations and may also result in high financial costs for companies. Flight behaviour plays a crucial role in collision risk, and the study of flight altitudes enables us to understand what drives birds to fly at collision risk altitudes. This allows the identification of high-risk areas, conditions and bird behaviours, and the implementation of mitigation measures by power line companies. In this study, we use boosted random tree modelling to identify drivers of white stork (Ciconia ciconia) flight altitudes and to investigate the factors that lead them to fly at collision risk altitudes. We found that the main drivers of flight altitude for this soaring bird species were time of day, distance to the nearest landfill site and cloud cover density. Bird age, habitat type and season were comparatively less important. Collision risk increases during crepuscular hours near landfill sites, also in days with high cloud cover density and during the breeding season. In recent years, hundreds to thousands of storks congregate daily at landfill sites to take advantage of the predictability and superabundance of anthropogenic food waste. Some of these sites have high density of power lines, becoming collision risk hotspots for storks and other landfill users. Despite being susceptible to collision, our results suggest that white storks can avoid power lines to a certain extent, by changing their flight altitude at ca. 80 m from these structures. This study shows that the implementation of mitigation measures for existing power lines should be prioritized in areas in the vicinity of landfill sites within white stork distribution ranges, and the projection of new lines should avoid those areas. These measures would benefit species vulnerable to mortality due to power line collision, and it would also reduce associated power outages and economic costs.

Assessing the Quality of Amazon Aquatic Ecosystems with Multiple Lines of Evidence: The Case of the Northeast Andean Foothills of Ecuador.

We assessed the quality of Andes-Amazonia streams in Ecuador impacted by gold mining (GM), discharges from inefficient sewage network in urban areas (UA), wastes from fish farming (FF) and from non-functional landfill (LF) and other few threats (FT). We selected three lines of evidence (LOE) that were used separately and integrated into a index: water quality (WQI) and macroinvertebrate community (AAMBI) indices and phytotoxicity tests. Streams affected by UA and LF had the lowest scores to WQI and phytotoxicity, and by GM had the lowest scores to AAMBI. Macroinvertebrate absence in GM should be considered as a warning signal of long-term mining impacts in the area. The integrated LOE index showed that sites with identified threats had 30%-53% stream quality decline compared to FT sites. The use of the selected LOE seems to be a useful tools for long-term monitoring and evaluation of this sensitive aquatic ecosystem.