Pollutants

Acid mine drainage (AMD), which is primarily caused by the exposure of sulfidic minerals to oxygen and water during mining operations, remains a significant contributor to environmental pollution. Numerous technologies have been developed to prevent/control and treat AMD, including the isolation of waste from the atmosphere and treatment systems for AMD-impacted water. Many field studies on mine site reclamation have involved an individual AMD source and/or technology, with a limited number of studies looking at reclamation programs integrating multiple approaches to manage AMD stemming from both surface and underground sources. The former Franklin mine site in Nova Scotia, Canada, was impacted by the deposition of waste rock across the site and the discharge of mine water from underground workings, with the adjacent Sullivan’s Pond serving as the main environmental receptor. Site reclamation was completed in 2010 and involved the following: (1) excavation of the dispersed waste rock (117,000 m²) and backfilling with clean soil; (2) consolidation of the excavated waste rock into a covered, compact waste rock pile (WRP) (25,000 m²); and (3) construction of a passive treatment system for the discharging underground mine water. An extensive field sampling program was conducted between 2011 and 2018 to monitor a range of meteorological, cover material, waste rock, groundwater, and surface water quality parameters. The results confirm that the multi-layer, geomembrane-lined WRP cover system is an extremely effective barrier to air and water influx, thereby minimizing the rate of AMD generation and seepage into groundwater and eliminating all contaminated surface water runoff. A small AMD groundwater plume emanates from the base of the WRP, with 50% captured by the underground mine workings over the long term and 50% slowly migrating towards Sullivan’s Pond. Excavation of the former waste disposal area eliminated the AMD source from the previously dispersed waste, with only clean surface water runoff and a diminishing legacy groundwater plume remaining. Finally, the passive treatment system, which contains a series of treatment technologies such as a limestone leach bed and settling pond, successfully treats all mine water loading (~50 kg/day) discharging from the underground workings and surface runoff. Its additional treatment capacity (up to ~150 kg/day) ensures it will be able to manage any potential drop in treatment efficiency and/or increased AMD loading from long-term WRP seepage. This comprehensive study of mine site reclamation and AMD management at an abandoned mining site can be of great reference value for environmental management and policymakers in the mining sector. Full article

Cigarette butts (CBs) are emerging soil contaminants, releasing chemicals upon contact with moisture. This study examined heavy metal concentrations leached from smoked and unsmoked CBs (Pall Mall, Philip Morris, and Marlboro) into OECD artificial soil and Vertisol soil and their accumulation in white mustard (Sinapis alba L.). Key physiological parameters, including germination rate, plant height, fresh weight, and dry weight, were analyzed, along with the uptake of heavy metals (Al, Fe, Mn, Zn, Ba, Ti, and Cu) and essential elements (Ca, Mg, Na, and K). Results showed that Mn had the highest bioaccumulation index (BAI = 1.10) in OECD soil, while Zn uptake was consistently high across soil types. Soil type significantly influenced plant height (χ² = 41.269, p < 0.01) and elemental composition, with Vertisol soil facilitating greater overall growth and heavy metal uptake than OECD soil. MANOVA revealed no three-way interaction among soil type, CB use, and CB brand on elemental uptake. However, two-way interactions, particularly between soil type and CB use (F (4, 39) = 40.233, p < 0.001, Wilk’Λ = 0.195), showed significant effects on heavy metal uptake. These findings highlight the complex interactions influencing plant contamination, underlining the ecological risks of CB pollution in soils. Full article

Analyzing the fluctuations of particulate matter (PM) concentrations and their scaling correlation structures are useful for air quality management. Multifractal characterization of PM2.5 and PM10 of three cities in India wase considered using the detrended fluctuation procedure from 2018 to 2021. The cross-correlation of PM concentration in a multifractal viewpoint using the multifractal cross-correlation analysis (MFCCA) framework is proposed in this study. It was observed that PM2.5 was more multifractal and complex than PM10 at all the locations. The PM–gaseous pollutant (GP) and PM–meteorological variable (MV) correlations across the scales were found to be weak to moderate in different cities. There was no definite pattern in the correlation of PM with different meteorological and gaseous pollutants variables. The nature of correlation in the pairwise associations was found to be of diverse and mixed nature across the time scales and locations. All the time series exhibited multifractality when analyzed pairwise using multifractal cross-correlation analysis. However, there was a reduction in multifractality in individual cases during PM–GP and PM–MV paired analyses. The insights gained into the scaling behavior and cross-correlation structure from this study are valuable for developing prediction models for PMs by integrating them with machine learning techniques. Full article

Microplastics, defined as plastic particles less than 5 mm in size, have become a pervasive environmental contaminant detected across a wide range of ecosystems. While the presence of microplastics in marine life and humans has been extensively documented, there remains a significant gap in understanding their full health impacts. Moreover, the effects of microplastics on animals, particularly those in close proximity to human activities, remain underexplored, representing a key area for future research. In this study, we found high levels of microplastic accumulation in animal tissues, particularly in the lungs, intestines, and reproductive organs. Our results also indicate that ingestion of microplastics occurs through multiple environmental sources, including contaminated food, water, and air, reflecting their widespread distribution. Evidence of microplastics crossing biological barriers and accumulating in critical organ systems suggests potential long-term health risks for animals that may also have implications for humans through environmental and food-chain exposure. Given the interconnectedness of ecosystems and the potential for these contaminants to enter the food chain, the presence of microplastics in animals raises serious concerns for broader ecological and human health. The findings underscore the urgent need for further research to clarify the long-term effects and to develop effective strategies for mitigating this emerging global threat. Full article

Atmospheric pollution of metals negatively impacts the health of terrestrial and aquatic plants and animals. Despite implementation of policies that have substantially decreased emissions of metal pollutants, their legacy continues in temperate forest ecosystems across the globe. Here, we evaluated throughfall and litterfall concentrations and fluxes of Cu, Zn, Cd, and Pb via in rural temperate forests along the Appalachian Mountain range in eastern United States. Our five years of data show that throughfall fluxes of Cu, Cd, and Pb have decreased >89% since the 1980s. However, throughfall Zn and litterfall Cu, Zn, and Cd fluxes remain comparable or greater than the 1980s. These results suggest that Cd, Cu, and Pb emissions have decreased, but trees retain and recycle Cd, Cu, and Zn pollution, extending their legacy for decades following the emission. Full article

The Tula industrial area in Central Mexico comprises, among other industries, a refinery and a thermoelectric power plant. It is well known for its constant emissions of gases into the atmosphere and considered an important area where pollutants released into the atmosphere have an influence on local and regional air quality. During March and April 2017, a field campaign was conducted with the objective of quantifying formaldehyde (HCHO), sulfur dioxide (SO₂), and nitrogen dioxide (NO₂) emissions from this industrial area using mobile differential optical absorption spectroscopy (DOAS) instruments. Calculated average emissions of the Francisco Perez Rios Power Plant and the Miguel Hidalgo Refinery were 3.14 ± 2.13 tons per day of HCHO, 362.08 ± 300.14 tons per day of SO₂, and 24.76 ± 12.82 tons per day of NO₂. From the measurements conducted, the spatial distribution patterns of SO₂, NO₂, and HCHO were reconstructed, showing a dispersion pattern of SO₂ and NO₂ towards the southwest of the industrial complex, impacting agricultural and urban areas. Occasionally, and usually during the morning hours, SO₂ and NO₂ were dispersed towards the north or northeast of the industrial complex. In the case of HCHO, dispersion was observed towards the south and southeast of the industrial complex. The far-reaching implications of this study are that for the first time, formaldehyde emissions were quantified. In addition, a follow-up study was conducted regarding nitrogen dioxide and sulfur dioxide emissions from the Tula Industrial area. Full article

Nitrite is a common pollutant in marine environments and can cause mortality in crustaceans and bivalves. The purpose of the current study is to understand nitrate’s toxicity to juvenile clams due to its potential impact on aquaculture and marine ecosystems. Juvenile sunray surf clams (Mactra chinensis Philippi) (1.00 ± 0.10 cm shell length, 0.75 ± 0.04 cm shell height) were exposed to varying concentrations of nitrite for 96 h and 20 days, respectively. The LC₅₀ for survival at 96 h was 37 mg/L NO₂-N. Histological evaluations were made on juvenile clams exposed at 30 mg/L after 20 d of exposure. Epithelial cells and digestive diverticulum are the best sub-lethal effect indicators. Shell length and antioxidant enzyme activities were measured at the beginning of the experiment and then observed 10 and 20 days after exposure. A logarithmic relationship was obtained between the relative growth rate (based on the shell length) of juvenile M. chinensis and the nitrite concentration. Compared to the control, activity suppression of superoxide dismutase and catalase activity was detected from the concentration of 1 mg/L NO₂-N. It is recommended that nitrite concentrations remain below 1 mg/L to prevent stress during the early developmental stages of clams. Full article

This work aims to assess the bioavailability and bioaccumulation of Cr, Cu, Pb, and Zn in the soil–plant system (Erigeron canadensis L.) in the zone of anthropogenic impact in Dnipro city, a significant industrial and economic centre of Ukraine. Sampling was carried out at three locations at distances of 1.0 km, 5.5 km, and 12.02 km from the main emission sources associated with battery production and processing plants in Dnipro. The concentrations of heavy metals such as Cr, Cu, Pb, and Zn were analysed using atomic emission spectrometry from soil and parts of Erigeron canadensis L. The highest concentrations of elements in the soil, both for the mobile form and the total form, were determined to be 48.96 mg kg⁻¹ and 7830.0 mg kg⁻¹, respectively, for Pb in experimental plot 1. The general ranking of accumulation of elements in all experimental plots, both for the plant as a whole and for its parts, was as follows: Zn > Cu > Cr > Pb. Zn for plants was the most available heavy metal among all studied sites and had the highest metal content in the plant (339.58 mg kg⁻¹), plant uptake index (PUI-506.84), bioabsorption coefficient (BAC-314.9), and bioconcentration coefficient (BCF-191.94). According to the results of the study, it is possible to evaluate Erigeron canadensis L. as a hyperaccumulator of Zn, Cu, and Cr and recommend it for phytoextraction of soils contaminated with Zn, Cu, and Cr and phytostabilization of soils contaminated with Pb. Full article

The emergence of infectious disease outbreaks and ‘superbugs’ related to pollution combined with climate change is a current problem, not just a future threat. In May 2024, an extreme flood hit the Rio Grando Sul State, southern Brazil, triggering an important leptospirosis outbreak in urban settings with deficient sanitation systems. This and other cases discussed in this article exemplify how extreme weather events exacerbate the consequences of environmental pollution by multiple classes of pathogens in the global scenario of increasing anthropogenic pressures on the environment. A combination of actions to combat climate change and improvements in sanitation systems is essential to mitigate this problem. Full article

Aquaculture and waste valorization have the potential to show solid achievements toward food security and improvements in the circularity of resources, which are crucial aspects of achieving a sustainable lifestyle in agreeance with Agenda 2030 goals. This study aims to optimize and simplify the decision-making processes for the valorization of marine wastes (natural and from aquaculture) as secondary raw materials to produce high-value-added market goods. However, significant concentrations of pollutants may be present within wastes, compromising overall quality, and social dynamics can hinder their usage further. Goro’s lagoon was chosen as a case study, where the relations between the ecosystem services, a thriving bivalve economy, and social dynamics are deeply rooted and intertwined. Therefore, in the manuscript cost–benefit and foresight analyses are conducted to determine the best usage for algal biomass considering pollution, social acceptance, and profitability. These analyses are virtually conducted on bio-refineries that could be operating in the case study’s area: briefly, for a thirty-year running bio-plant, the CBA indicates the two best alternatives with an income of 5 billion euros (NPV, with a 5% discount rate) for a biofuel-only production facility, and a half for a multiproduct one, leading to the conclusion that the first is the best alternative. The foresight, instead, suggests a more cautious approach by considering external factors such as the environment and local inhabitants. Hence, the main innovation of this work consists of the decision-maker’s holistic enlightenment toward the complexities and the hidden threats bound to this kind of closed-loop efficiency-boosting process, which eventually leads to optimized decision-making processes. Full article

Application of hydraulic fracturing to produce “unconventional” oil and gas from shale formations and other low-permeability geological units has raised concerns about the potential environmental impacts, including potential adverse effects of fracturing fluids (FF) on groundwater. In this study, laboratory batch test experiments and new analytical methods were developed to analyze FF chemicals as potential indicators (tracers) to detect impacts of fracturing fluids on groundwater. The tests, conducted over 101–196 days, included FF with synthetic chemicals (~40,000–4,000,000 µg/L), placed in batches with groundwater and sediment at 5° and 25 °C, along with sterile controls. Using the new methods, measurable concentrations of the FF chemicals were many orders in magnitude lower (~3000 to 3,000,000 X) compared to their concentrations in synthetic fracturing fluids, indicating that these chemicals are excellent candidates as indicators of FF contamination in groundwater, if they are relatively persistent, and not prone to extensive loss by sorption during migration in the subsurface. Variable sorption and degradation of the chemicals was observed in both batch and column tests. Sorption was negligible (sorption coefficient, K_d~0.0) for some synthetic chemicals (polyethylene glycol, ethanolamines, isopropanol, and ethyl hexanol) in some tests. At the other extreme, strong sorption was observed for some of the higher molecular weight cocamido propyl betaine (max K_d = 1.17) and polyethylene glycol (max K_d = 1.12) components, and triethanolamine (max K_d = 0.47) in other tests. Apparent loss by degradation was observed for each chemical in some tests, but negligible in others. The shortest apparent half-lives were for isopropanol and ethyl hexanol at 25 °C (t^½ < 11 days), and the most persistent synthetic chemicals were polyethylene glycols (t^½ ≥ 182 d) and the ethanolamines (t^½ ≥ 212 d). Of the potentially diagnostic FF chemicals investigated, the relatively hydrophilic and persistent lower molecular weight polyethylene glycols are some of the most promising as potential indicators of contamination of groundwater by FF. Full article

In the present study, the toxicity of nicosulfuron to Danio rerio embryos was evaluated in three experiments through standardized toxicity tests according to OECD TG236 guidelines. In the first experiment, six concentrations of nicosulfuron (0, 0.1, 1, 10, 100, 1000 mg/L) were tested under optimal conditions (26 °C, pH 7.0) to assess the general sensitivity of zebrafish embryos to nicosulfuron. The second and third experiment examined the effects of different pH levels (5.0 and 9.0) and temperatures (21 °C and 31 °C) on the toxicity at four nicosulfuron concentrations (0, 10, 100, 1000 mg/L). Additionally, the sub-organismic effects of nicosulfuron on stress protein levels (Hsp70) of fish embryos were analyzed. Throughout the embryo experiments, no malformations were observed in all experiments. The survival rate exceeded 80% in all groups except for the 21 °C (pH 7.0) treatment groups. No significant effect of nicosulfuron on the survival rate was found at the same temperature or pH (p > 0.05). No significant difference in the heart rate was found among all nicosulfuron groups (p > 0.05) at 21 °C. The heart rate of fish embryos at 31 °C, pH 5.0 and pH 9.0 increased with nicosulfuron concentrations. Except for the pH 5.0 (26 °C) and 21 °C (pH 7.0) treatment groups, nicosulfuron was found to increase the hatching rate of embryos in other treatments; however, the corresponding times of action were different. At 21 °C (pH 7.0), the embryos did not hatch until 144 h post-fertilization. In terms of proteotoxicity, nicosulfuron was found to be more toxic to zebrafish embryos in the 21 °C, pH 5.0 and pH 9.0 treatment groups. However, at 31 °C, no significant difference in Hsp70 levels was found among all the different nicosulfuron concentrations (p > 0.05). Our results show that nicosulfuron exerts a weak toxicity to zebrafish embryos; however, this toxicity is amplified by inappropriate pH or temperature conditions. Full article

While many sources of contamination in chemical and biological laboratories are well understood and known, some are less so. To quantify the magnitude of the potential contamination of solutions by zinc in common laboratory syringes, a study was conducted on solutions stored in rubber-containing syringes in which the rubber was catalyzed by zinc. This study identified specific factors contributing to contamination from laboratory syringes, including the syringe brand, time, solution type, and pH. Two common syringe brands, Covidien and BD, were tested, and three time durations, 0 days, 1 day, and 14 days, were examined. The solutions tested included sucrose and tartaric acid, representing both covalent and ionic species. Additionally, this study employed a pH range of 2 to 13 to further explore zinc contamination across a wide range of conditions and factors. The zinc concentration from the syringes was measured using inductively coupled plasma mass spectrometry (ICP-MS). The results, which ranged from less than 20 to over 600 μg L⁻¹, revealed increased zinc concentration at both extreme pH values, while remaining lower but measurable at neutral pH levels. Zinc contamination is important to study because its contamination in laboratory syringes could interfere with the detection of other elements, further skew laboratory data, unexpectedly catalyze reactions, and lead to inconsistencies in experimental conditions. This study further emphasizes the broader significance of understanding pollutants within laboratory settings. The findings highlight the intricate dynamics of zinc contamination, stressing the need for the control of environmental factors and the broad dissemination of lesser-known sources. Recognizing the potential impact of contaminants like zinc is crucial, as it not only influences analytical accuracy, but also mirrors the wider concern of pollutants compromising scientific integrity in diverse experimental conditions. Full article

Cadmium accumulation in wheat as a daily food, even in low concentrations, is a serious threat to human health. Previous studies have reported conflicting results on the impact of calcium treatments on cadmium uptake and translocation in plants due to the complex soil conditions. Our hydroponic study offers clearer insights into how specific calcium treatment parameters influence cadmium uptake and translocation in wheat. The hydroponic medium was contaminated by cadmium (CdCl₂) and the following treatments were applied: CaCO₃, CaSO₄, CaCl₂, CaCO₃ + CaSO₄, CaCO₃ + CaCl₂, and CaSO₄ + CaCl₂. After harvesting, the wheat was analyzed for Cd²⁺ uptake characteristics including translocation factor, bioconcentration factor, and uptake. Furthermore, physiological growth parameters and plant nutrients were also determined. Applying CaCO₃ significantly decreased wheat Cd²⁺ concentration by about three times in CaCO₃ and two times in CaCO₃ + CaSO₄ and CaCO₃ + CaCl₂ treatments than in Cd-control. This study clearly elucidates that pH and CO₃²⁻ were crucial in reducing Cd²⁺ concentration in wheat. SO₄²⁻, Cl⁻, and Ca²⁺ showed no effect on Cd²⁺ concentration. Ca²⁺ only reduced the translocation factor (TF) of Cd²⁺ in plants. CaCO₃ also declined cadmium interference in the Mg²⁺, Mn²⁺, and Cu²⁺ uptake. Therefore, this study provides novel insight into the pure effects of calcium treatments on controlling cadmium contamination in plants, independent of soil effect. Full article

End-of-life vehicle (ELV) forecasting constitutes a crucial aspect of sustainable waste management and resource allocation strategies. While the existing literature predominantly employs time-series forecasting and machine learning methodologies, a dearth of studies leveraging deep learning techniques, particularly Long Short-Term Memory (LSTM) networks, is evident. Moreover, the focus on localized contexts within national or municipal boundaries overlooks the imperative of addressing ELV generation dynamics at an international scale, particularly within entities such as the EU-27. Furthermore, the absence of methodologies to reconcile missing historical data presents a significant limitation in forecasting accuracy. In response to these critical gaps, this study proposes a pioneering framework that integrates grey systems theory (GST)-based backcasting with LSTM-based deep learning methodologies for forecasting ELV generation within the EU until 2040. By introducing this innovative approach, this study not only extends the methodological repertoire within the field but also enhances the applicability of findings to supranational regulatory frameworks. Moreover, the incorporation of backcasting techniques addresses data limitations, ensuring more robust and accurate forecasting outcomes. The results indicate an anticipated decline in the recovery and recycling of ELVs, underscoring the urgent need for intervention by policymakers and stakeholders in the waste management sector. Through these contributions, this study enriches our understanding of ELV generation dynamics and facilitates informed decision-making processes in environmental sustainability and resource management domains. Full article

The use of stable isotopes, specifically δ¹⁸O_PO4 ratios, in differentiating potential sources of inorganic phosphorus (e.g., wastewater, septic, wild animals, domesticated animals, livestock, substrates, or commercial fertilizers) to watersheds is a growing field. This method produces data that, used in conjunction with statistical mixing models, enables a better understanding of contributing sources of runoff. However, given the recent development of this research area there are obvious limitations that have arisen, due in large part to the limited available reference data to compare water samples. Here, we attempt to expand the availability of reference samples by applying stable isotope methods to three types of common agricultural manures: poultry, dairy, and swine. We also aim to concatenate the organic waste literature on this topic, creating a more robust comparison database for future study and application in phosphorus source partitioning research. Among our samples, δ¹⁸O_PO4 ratios for poultry were considerably elevated compared to dairy and swine manures (values of 18.5‰, 16.5‰, and 17.9‰, respectively). Extending this to other published ratios of δ¹⁸O_PO4 from various types of waste products (e.g., septic, wastewater, livestock, other animals), a total range from 8.7‰ to 23.1‰ emerged (with existing poultry manure samples also ranking among the highest overall). Variation among samples in the larger dataset demonstrates the need for a further compilation of δ¹⁸O_PO4 ratios for various types of waste, especially specific to geographic regions and watershed scales. With an increased sample size, the statistical strength associated with these methods would greatly improve. Full article

A 2018 report from the Water Quality for Human Consumption Vigilance Information System (SISÁGUA, Brazil) showed the presence of 27 pesticides in Brazilian drinking water, of which 11 have carcinogenic potential. We assessed the data for 27 municipalities in Paraná state southwest, a rural landscape with high cancer rates. We selected data from the carcinogenic potential of 11 pesticides provided by international agencies (alachlor, aldrin-diheldrin, atrazine, chlordane, DDT, diuron, glyphosate, lindane, mancozeb, molinate, and trifluralin) and estimated the number of cancer cases attributable to drinking water contamination by pesticides. Also, we correlated such findings with incidence and mortality cancer rates for ten topographies obtained from the Brazilian National Cancer Institute (INCA) database. A total of 9 cities were selected, corresponding to about 81,000 people. All towns had all pesticides quantified in the drinking water. About ten cancer cases were attributed to drinking water contamination by pesticides in 2014–2017, mainly linked to diuron and mancozeb. Concerning the consolidated incidence of cancer cases reported by the INCA, significant correlations were found regarding aldrin-diheldrin, alachlor, and atrazine for breast cancer, atrazine for prostate cancer, and mancozeb and diuron for colon cancer, among others. Regarding the consolidated mortality rates, some correlations were found between DDT and trifluralin for the breast, DDT and lindane for the prostate, and glyphosate for lung cancer. Moderate correlations were found between the estimated and consolidated cancer cases for several topographies. Our findings highlight the correlation between drinking water contamination in Paraná state southwest and its increased incidence of cancers with poor prognosis. Full article

Soil contamination by metallic components is an obscure, detrimental, protracted, and irreparable predicament. Dumping of waste containing heavy metals into landfills, fertilizer and pesticide application, and coal combustion results in high toxicity of metallic elements, and their continuous accumulation in soil pollutes the environment, which, in turn, poses a threat to human health. The specimens were subsequently dehydrated, processed for mineralization, and carefully examined microscopically by scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDX), which examined their mineral substance, crystalline configuration, and chemical composition. Thirteen (13) elements were detected, and only eight (8) metals were discovered (K, Mg, Na, Ca, Al, Fe, Au, Ba), including non-metals (C, O, Cl, P) and a metalloid (Si). The concentrations of possibly toxic elements obtained showed no consistent succession, as they fluctuated across the examined sites. The Al concentration ranged from 3.78 ± 0.23 wt% to 10.23 ± 0.31 wt%, while the Fe concentration fluctuated from 4.14 ± 0.40 wt% to 13.13 ± 1.07 wt%. Na and Mg levels were present in all samples, but their availability was minimal, at less than 2.0 wt%, ranging between 1.44 ± 0.20 wt% and 0.31 ± 0.08 wt%. The concentrations of Ca and K were low in all soil samples, ranging from 0.91 ± 0.14 wt% to 5.56 ± 0.47 wt% for Ca and from 1.32 ± 0.25 wt% to 4.87 ± 0.18 wt% for K. During the investigation at the designated and control areas, it was discovered that the concentrations of potentially hazardous metals exceeded the accepted limits established by the World Health Organization (WHO) > 100 ppm. The findings provide proof of metallic contaminants in the study region, which calls for proper monitoring, management, and remedial measures of metal-tainted sites, since the residents of this locality are at a significantly elevated risk of experiencing adverse effects due to their heightened exposure to these elements. As a result of that, there is an imperative need to monitor and regulate this area regularly and appropriately. The study recommends sustainable farming practices, where farmers could use natural fertilizers and compost, as well as, the implementation of proper waste management, effective recycling techniques, and proper disposal of substances containing heavy metals as byproducts. Further implement remediation techniques that effectively and safely restore soils contaminated by metals in an environmentally sustainable and economically efficient manner. Full article

Artisanal small-scale gold mining (ASGM) using mercury affects community agreements for the conservation of forests (CoS) and lakes (CoH), which have a high level of biodiversity in the Peasant Reserve Zone of the Cimitarra River Valley (ZRC-VRC) in Colombia. In this research, a multi-criteria approach (MCA) was applied to analyze the impact of ASGM. This analysis is based on the community environmental agreements to preserve CoS and CoH areas, the ecological importance of these areas, as well as the results of mercury dispersion in the Cimitarra river basin, with concentrations found 40 km downstream of the mining area of 0.09 µgTHg L⁻¹ in the Cimitarra river, 0.07 µgTHg L⁻¹ in the CoH, and 0.01 mgTHg kg⁻¹ in the tissues of macrophytes, as well as the increase in deforestation since 2020 in the CoS, due to a 1.8% (990 ha) loss of forest cover, with 693 ha of the forest cover loss coinciding with areas related to the opening of new mines. The MCA showed that the main impact is found within the criterion Social and armed conflict, followed by Deforestation. This research offers recommendations to reduce impact scores, such as the implementation of a sustainable development plan (PDS) of the ZRC-VRC, and it highlights the urgent need to safeguard the community conservation areas. Full article