Integrated Environmental Assessment and Management最新文献

The rising frequency and severity of landslides in the vulnerable Himalayan region of India threaten human settlements and critical infrastructure. This growing issue demands urgent action and innovative strategies to mitigate risks and bolster the resilience of affected communities and infrastructure in this fragile area. The research explores the use of Alnus nepalensis for slope stabilization, illustrated by a case study near Ukhimath, Uttarakhand, India, and elucidates the potential ecological niche of Alnus in the temperate region of Uttarakhand using well-dispersed species occurrence records along with environment. The study used Sentinel-2 (2021) data for land use and land cover (LULC) mapping and Landsat 4-5, Sentinel-2, and Google Earth imagery from 1998, 2004, 2015, 2019, and 2020 for landslide slope recovery assessment. The Ukhimath landslide, spanning 54.61 ha in August 1998, demonstrated a remarkable recovery, with 98.20% coverage of Alnus by 2020, showcasing the species efficacy in stabilizing slopes without human intervention. The research forecasts a total potential distribution area of Alnus in the temperate region (1,000-2,500 m·asl [above mean sea level]) of Uttarakhand as ∼7,833 km2, with 782.30  km2 highly suitable, 2,104.33  km2 moderately suitable, and the rest showing low suitability. These distribution insights provide a foundation for in situ planning to leverage Alnus-based bioengineering for early slope stabilization, which is especially relevant in landslide-prone areas like Uttarakhand. The study provides a comprehensive and scientifically rigorous strategy for achieving sustainable outcomes in landslide-prone areas, particularly in the lower temperate region of the Himalaya.

This study evaluated a novel ex situ passive sampling biomimetic extraction (BE) method to estimate toxic potency in sediments. Gas chromatography with flame ionization detection (GC-FID) analysis of polydimethylsiloxane fibers equilibrated with field sediments was used to quantify bioavailable polyaromatic hydrocarbons (PAHs) and other unresolved, site-specific contaminant mixtures. This method is biomimetic because contaminants partition to the fiber based on hydrophobicity and abundance, and GC-FID quantification accounts for all constituents absorbed to the fiber that may contribute to toxicity. This measurement was compared with conventional approaches that rely on bulk sediment or porewater measurements of a targeted suite of PAHs. The specific objectives of the study were to (1) describe the BE method and explain measurement translation into toxic units (TUs); (2) report sediment BE data collected across 17 diverse field sites; (3) compare TUs predicted from (i) equilibrium partitioning (EqP) calculations based on sediment total organic carbon and bulk PAH chemistry, (ii) PAH porewater concentrations derived using ex situ passive sampling, and (iii) BE concentrations; and (4) discuss implications of this analysis for benthic toxicity assessment. Results showed that TUs obtained from EqP calculations were typically 10× higher than TUs derived from measured porewater PAH concentrations, indicating reduced PAH bioavailability in field sediments. Toxic units derived using the new BE method were more conservative than EqP in one-third of the sediments investigated, which was attributed to unquantified sediment contaminants, possible fiber fouling in the more contaminated sediments, and potential background interferences in less contaminated sediments. Preliminary data are also presented, showing that fluorometric analysis provides a simpler, promising alternative for estimating sediment BE concentrations. Based on this analysis, a decision-support framework is proposed using EqP and BE based TU metrics. Future research priorities are described for supporting framework implementation and extending use of BE analyses to remedial design and monitoring.

The U.S. Environmental Protection Agency is committed to the implementation of new approach methodologies (NAMs) to enhance the scientific basis for chemical hazard assessments. Chemical evaluations under the Toxic Substance Control Act (TSCA) are often conducted with limited test data and are well suited for NAMs applications. Interspecies correlation estimation (ICE) models are log-linear least squares regressions of the sensitivity between two species that estimate the acute toxicity of an untested species from the sensitivity of a surrogate. Interspecies correlation estimation models have been developed from and validated for diverse chemical modes of action, but their application in TSCA chemical assessments has not been previously evaluated. We use ICE models and a dataset of measured acute values for five chemicals, increasing the taxonomic diversity from which concentrations of concern (CoCs) are derived. Concentrations of concern were developed using approaches typically applied in TSCA risk evaluations, including application of assessment factors to the most sensitive species and the development of species sensitivity distributions where a minimum of eight species are represented by measured data. These CoCs were compared with those derived from datasets supplemented with ICE-predicted values, as well as comparing ICE predicted species mean acute values (SMAVs) to their respective measured values. Interspecies correlation estimation models predicted SMAVs within a factor of 5 and 10 for 87% and 92% of measured values, respectively. The CoCs developed from measured data only and data supplemented with ICE predicted toxicity were generally within five-fold, showing comparable protection. The taxonomic diversity in the ICE supplemented dataset was substantially higher than the measured data for species sensitivity distributions, providing a data-driven way of reducing uncertainty and potentially reducing the need for assessment factors. Interspecies correlation estimation models show promise as a NAM to improve the taxonomic representation included in chemical evaluations under TSCA.

Selenium (Se) contamination of aquatic ecosystems has led to the local extirpation of some Se-sensitive fish species. Although Se exposure occurs primarily via diet, considerable uncertainty lies in modeling Se transfer and bioaccumulation from sediment, detritus, and/or periphyton through benthic macroinvertebrates (BMI) to fish. Here we estimated Se concentrations in four coldwater fish species (northern pike, white sucker, lake whitefish, and ninespine stickleback) inhabiting boreal lakes downstream from a uranium mill in northern Canada. In addition, we evaluated the potential effects of BMI and periphyton sampling methods (artificial substrates vs. grab samples), seasons (summer vs. winter), and models (USEPA vs. Assessment of the Dispersion and Effects of Parameter Transport) on the estimated Se concentrations in fish tissue. Results were compared with site-specific benchmarks and observed Se concentrations in resident fish. In summer 2019, periphyton and BMI were sampled at 10 sampling stations (two in Vulture Lake and eight in McClean Lake) using artificial substrates (n = 4) and sediment grab samples (n = 3). In winter 2021, samples were collected in McClean Lake (n = 3) through ice holes using a sediment grab sampler. Estimated Se concentrations in fish tissue depended on the surface sediment or periphyton Se concentrations used in the models. At Vulture Lake, Se concentrations in northern pike muscle estimated using the grab sample data (17.3 ± 11.5 µg/g DW), but not the artificial substrates (34.5 ± 1.2 µg/g DW), were comparable with the observed mean concentration (19.0 ± 1.4 µg/g DW) in this species. At McClean Lake, Se body burdens in forage fish estimated using data from both sampling methods were comparable with measured data. Significantly lower mean whole-body Se concentrations were estimated for all fish species in winter (1.0 ± 0.3 µg/g DW) relative to summer (4.8 ± 1.6 µg/g DW). Further investigation is necessary to understand how potential seasonal shifts in dietary Se exposure relate to fish reproduction and early life stages.

Selenium (Se) is a naturally occurring metalloid in soils and rocks that is released by weathering processes; it is also enriched by some anthropogenic activities, including mining and agriculture. The mechanism of Se aquatic toxicity has been understood for several decades; at elevated concentrations, dietary Se can accumulate in maternal tissues of fish and birds, become deposited into their eggs, and can potentially result in impaired embryological development. North American environmental regulations have acknowledged differences in species sensitivity and variation among aquatic environments (i.e., lentic and lotic) that influence Se toxicity. The above subjects were thoroughly reviewed in a state-of-science SETAC Pellston workshop and book, entitled Ecological assessment of selenium in the aquatic environment, published in 2010. Since the publication of that book, regulatory guidance in North America has evolved further to enhance the protection of aquatic life exposed to Se. This IEAM special series entitled "Regulatory issues surrounding the management of selenium" is a compilation of recent research and reviews from North American experts addressing critical environmental, physiological, and operational factors warranting consideration in support of Se regulatory frameworks.

The proliferation of cyanobacteria has become a significant water management challenge due to the increasing eutrophication of water supply reservoirs. Cyanobacterial blooms thrive on elevated nutrient concentrations and form extensive green mats, disrupting the local ecosystem. Furthermore, many cyanobacterial species can produce toxins that are lethal to vertebrates called cyanotoxins. Traditional monitoring methods are inefficient for assessing water quality in reservoirs as a whole, given that sampling is only carried out in the catchment area for the public water supply, which exposes the population to the risk of contamination due to the multiple uses of these reservoirs. Therefore, novel monitoring methods supported by recent technological advances, such as the use of unmanned aerial vehicles (UAVs), are being tested for their effectiveness in monitoring cyanobacterial densities in aquatic ecosystems. This study analyzed UAV images of two water supply reservoirs to assess the effectiveness in monitoring cyanobacterial density. The UAVs were equipped with RGB sensors and flew over the study areas on the same day and at the same locations as water sampling performed for the determination of phytoplankton density, biovolume and chlorophyll-a. The phytoplankton community was dominated by cyanobacteria in both reservoirs. High coefficients of determination were obtained in the predictive models for chlorophyll-a concentration (r2 = 0.92), total phytoplankton and cyanobacterial densities (r2 = 0.89 and r2 = 0.97, respectively), and total phytoplankton and cyanobacterial biovolumes (r2 = 0.96 for both). Applying the predictive models to the orthomosaics generated from the UAV RGB images enabled the visualization of the spatial distribution of the phytoplankton and cyanobacterial biomass through distribution maps. This method has potential application in the management of water bodies that are crucial to the public water supply.

Current publications that are shaping public perception repeatedly claim that residues of plant protection products (PPP) in the environment demonstrate gaps in assessing the exposure and effects of PPP, allegedly revealing the inability of the European regulatory system to prevent environmental contamination and damage such as biodiversity decline. The hypothesis is that environmental risk assessments rely on inappropriate predictive models that underestimate exposure and do not explicitly account for the impact of combinations of environmental stressors and physiological differences in stress responses. This article puts this criticism into context to allow for a more balanced evaluation of the European regulatory system for PPP. There is broad consensus that the decline in biodiversity is real. This article analyzed current literature for causes of this decline and of chemical contamination. The main drivers identified were land use changes and structural uniformity of agricultural landscapes or multiple contaminants emitted by various sources such as wastewater discharge systems. Comparing measured environmental concentrations from published monitoring studies with exposure predictions from the regulatory risk assessment reveals only slight occasional exceedances for a few environmental scenarios and compounds. Therefore, the call for greater conservatism in the European authorization process for PPPs will not lead to an improvement in the environmental situation. We suggest enhancing landscape diversity through the European Union Common Agricultural Policy and reducing contamination from wastewater and farmyard effluents. The current regulatory risk management toolbox should be expanded to include flexible localized mitigation measures and treatment options to reduce applied amounts and off-target exposure.

Despite decades of fate and effects studies, environmental selenium (Se) contamination and management remain an issue for many freshwater systems in North America. Several regulatory bodies have promulgated updated targets or management levels for Se; however, additional guidance on best practices for monitoring Se to protect freshwater aquatic life is warranted. In this article, we describe current approaches to assessing the ecological risks of Se in impaired freshwater systems and outline recommended methods for collecting and analyzing biological and abiotic samples and interpreting data. Because reproductive impairment of fish populations is most commonly used to determine the potential impacts of Se, several biological factors that could affect Se toxicity are explored, including diet, trophic positions, reproductive biology, body size and maturity, migratory movements, and use of seasonal habitats. Measuring Se concentrations in mature eggs is the most reliable metric for estimating potential reproductive impairment in fish populations because the range of toxicity thresholds is relatively narrow for all but a few tolerant fish species. In situations where collecting mature eggs is not feasible, we review the use of alternative fish tissue for estimating potential effects. Factors affecting Se uptake from freshwater are also considered with guidance on collecting abiotic (e.g., water and sediment) and biotic components of aquatic food webs (e.g., macroinvertebrates, biofilm).

Waste has emerged as a pressing concern for the environment, primarily stemming from the processes of urbanization and industrialization. The substantial volumes of waste generated pose a serious threat to the environment, as they spread out harmful substances in the soil and release methane emissions into the atmosphere. To effectively address this issue, this study explores the impact of municipal and industrial waste, as well as waste-related innovation on the load capacity factor (LCF) from 2005 to 2020. For this purpose, the augmented mean group method and the half panel jackknife causality approach were conducted by using panel data from 17 European countries. The empirical findings show that (1) the load capacity curve (LCC) hypothesis is confirmed; (2) municipal and industrial waste have a detrimental effect on the LCF; and (3) innovation in waste management practices have no discernible impact on the LCF. In light of these findings, this study emphasizes the importance of efficient waste management for European countries to exploit the potential of waste as a valuable resource rather than a cause of pollution.