Sand dams are a form of rainwater harvesting, prolific in arid and semi-arid lands. Water is provided partly via handpumps, which, as the only improved method of abstraction from sand dams, are important for drinking water security. Accelerometers and cellular transmitters were fitted to 30 handpumps by the Africa Sand Dam Foundation (ASDF) in 2019 to monitor the use and reliability of the handpumps by recording hourly water volume abstracted. Data from April 2019 to October 2021 for 26 of these sites, alongside qualitative data, were analysed and each handpump’s contribution to year-round water security was explored, focusing on the long dry season when water supply from other sources is compromised. ion was over 20 times higher in the long dry season than in any other season, and at sites with higher salinity, higher livestock use, and larger dam wall area. At 21 wells, abstraction was still being recorded at the end of at least one long dry season; however, high spatial and temporal heterogeneity between pumps and seasons means that not all sand dams deliver reliable water supply year-round. Quantifying the contribution that sand dams make to water security is crucial for understanding their resilience against a changing climate and can aid decision makers when choosing the most appropriate water management technique. Knowledge of temporal and site heterogeneity in abstraction can inform when other water sources need increasing and can help with sand dam design optimisation. Overall, our results indicate the positive contribution that sand dams make to year-round water security through the water that is abstracted through handpumps.

In China, coal provides about 56.8% of the energy. Most of China's coal mines are shaft mines, which cause the surface to collapse and crack during the mining process. The soil near the cracks changes its physicochemical properties due to the altered stress conditions. This will affect the distribution of PTEs in the soil. We collected 18 samples from a selected crack in the abandoned land. The pH, Eh, and PTE and their fractions of the samples were determined. With the test results, we understand the distribution characteristics of pH, Eh, PTEs, and their fractions at the cracks. Meanwhile, we explored the key factors that contribute to this distribution. It was determined that crack decreases surface soil pH while increasing Eh. The total amount of 7 PTEs is higher in the bottom soil of the main crack and 2 m away from the main crack. The content of reducible fractions of PTEs increases with the increase of soil Eh. The oxidizable and residual fractions of PTEs adsorbed to the clay particles migrate to and enrich the deeper layers of the main crack. This study emphasizes the effect of crack generation on the distribution of PTEs in soil. It provides insights to describe the distribution of PTE throughout the full life cycle of crack.

During the green revolution in the mid-twentieth century, the consumption of inorganic phosphorous and phosphate-based fertilizers (P-fertilizers) in the developing world skyrocketed, resulting in a proliferation of P-fertilizer industries. Phosphate-based fertilizer industries are ranked among the most environment-polluting industries. The worldwide phosphorus market, which was 68.5 million metric tons in 2020, is expected to increase at a compound annual growth rate (CAGR) of 2.5% to 81 million metric tons by 2027. The release of untreated hazardous pollutants from these fertilizer industries into the soil, water, and atmosphere has resulted in severe environmental health issues. Excessive surface runoff of phosphorus from agricultural fields and its deposition in water promote the growth of algae and macrophytes and lower dissolved oxygen concentration through eutrophication, which is detrimental to aquatic life. Fluorides (F-) and sulfur dioxide (SO2) and/or heavy metals (potentially toxic elements, PTEs) are also detected in the emissions from these fertilizer industries. The main solid waste generated from the phospho-gypsum plant produced up to 5 tons of di-hydrogen phosphate (H2PO4), including PTEs and radioactive substances. Phosphates and fluorenes from these industries are usually disposed of as sludge in storage ponds or trash piles. Humans inhaling poisonous gases released from the P-fertilizer industries can develop hepatic failure, autoimmune diseases, pulmonary disorders, and other health problems. The objectives of this review are to provide guidelines for eliminating the bottleneck pollutions that occur from the phosphate-based fertilizer industries and explore the management practices for its green development.

Sewage sludge usage as agricultural soil amendment is a well-known practice employed worldwide. However, certain components may pose risks to the soil ecosystem. For a better verification of the potential adverse effects on the soil biota, biological assays have become an indispensable tool for an accurate understanding of the residue's behavior on soil, as well as its potential toxicity. Accordingly, to properly assess the effects of natural tropical soil (Oxisoil) amended with sewage sludge, we conducted toxicological tests with edaphic organisms (Enchytraeus crypticus and Folsomia candida) and microbial biomass (through respirometric assessment). Results indicate that E. crypticus and F. candida present similar reproduction sensitivity behavior to sewage sludge. For the microbiological analysis, the results suggest that microbial activity was stimulated by sludge application. For further evaluation of respiration of the microbial community and CO2 stabilization values behavior, Ford-Walford modeling was applied and presented limit values for sludge application in soil for 1.5gkg-1 and 15.0gkg-1 of, approximately, 55mg and 88mg, respectively. CO2 releases were faster and reached stability within 18weeks for the soil with higher sludge content (15.0gkg-1 of dry soil). In contrast, CO2 releases were slower for the soil with lower sludge content (1.5gkg-1 of dry soil), and until the experiment's final period (21weeks) respiration behavior did not reach stability. This study indicates that the stabilized sewage sludge, at the considered recommended application rate, presents a low toxicity risk for the studied bioindicators, being suitable for agricultural use.

The emission of bioaerosols in the ambient atmosphere from different sources is a cause of concern for human health and the environment. Bioaerosols are a combination of biotic matter like microbes and pollens. The present review emphasizes the understanding of various sources of bioaerosols (industries, municipal solid waste, and medical facilities), their components, and their impact on human health. The study of bioaerosols is of great importance as large numbers of people are estimated to be exposed on the global scale. Bioaerosols exposure in different work environments results in health issues such as infectious diseases, allergies, toxic effects, and respiratory problems. Hence, extensive research is urged to establish an effective assessment of bioaerosols exposure in the workplace, risks involved, distribution, and validation. The present review is intended to explore the relationship between bioaerosols exposure to the atmosphere and its impacts on human health. Some of the preliminary findings, based on our analysis of bioaerosols arising from municipal solid waste at a landfill site and a waste transfer station in Hyderabad, India, are also discussed herein.

Terrestrial ecosystems are under the enormous pressure of land use management regimes through human disturbances, resulting in the disruption of biogeochemical cycles and associated ecosystem services. Nitrogen (N) in soil ecosystems is of vital importance for primary productivity, hence estimating the extent of these human interventions on N-cycling processes becomes imperative from economic and environmental perspectives. This work investigated the impacts of variable anthropogenic activities on N cycling in three different terrestrial ecosystems (arable, grassland, and forest) in three regions of lower Himalaya, Pakistan. Potential nitrification (PNA) and denitrification (DEA) enzyme activities, relative distribution of inorganic N species (NH4, NO3), and the role of inherent edaphic factors were assessed. Results revealed high nitrification potentials and increased nitrous oxide (N2O) emissions in the incubated soil microcosms, in the order as arable > grassland > forest ecosystems. Notably, higher rates of both studied processes (~ 30-50%) and elevated soil mineral nitrogen pool were observed in arable ecosystems. Forest soils, assumed as pristine ecosystems relying mainly on natural N fixation, produced (de)nitrification rates relatively lower than grasslands, followed by arable soils which were moderately disturbed through long-term fertilization and intensive land-use regimes. Linear regression modeling revealed that the inorganic N species (particularly NO3), and inherent edaphic factors were the key determinants of high (de)nitrification rates, hence warn of accelerated N losses in these ecosystems. The study highlights that elevated PNA and DEA being proxies for the altered N cycling in the studied terrestrial ecosystems are of great ecological relevance in view of predicted N2O budget in the lower Himalaya.

During the operation of the landfills, leachate should be managed with caution to avoid possible negative environmental impacts. Considering this, the present study aims to evaluate the relationship between different variables in the leachate composition and elucidate the transformation processes through which this effluent passes during the landfill's period of operation. The study was conducted with eight sanitary landfills from the state of Minas Gerais, in southeastern Brazil, and used descriptive statistical analysis, principal component analysis (PCA), correlation analysis, and calculation of the leachate pollution index (LPI). The biochemical oxygen demand (BOD5)/chemical oxygen demand (COD) ratio was between 0.20 and 0.60. We also observed a significant correlation of 0.45 between Cl- and N-NH4+, which reflects the biological degradation processes that contribute to the presence of both variables. The PCA showed that inorganic variables and organic matter dominated the first component, with coefficients above 0.65, indicating the importance of those variables in determining the general data variability. The LPI values were between 15.26 and 25.97, with BOD5, COD, and N-NH4+ having sub-indexes above 35, being the main variables that increase the pollution potential of the leachate. On the other hand, trace metals present sub-indexes below 7 due to precipitation caused by increased pH and the characteristics of the waste discarded in landfills. The study provides essential information regarding the landfill leachate characteristics and its variation over time, which can contribute to the definition of treatment technologies for this affluent in different scenarios.

In this study, the extreme shrinkage of Urmia Lake is investigated, aiming to assess the impact of anthropogenic factors, particularly the over-construction of dams and natural anomalies associated with climate change. Historically available multispectral spatial data obtained from Landsat missions 4-5 TM and Landsat 8 OLI were utilized which totally covers a period of 36 years (1967-2020). Additionally, this data was employed to identify the locations of constructed water reservoirs and determine their construction timelines by analyzing the normalized difference vegetation index (NDVI). To examine the temporal patterns of annual precipitation in the lake basin, we obtained time series data from historical precipitation records, which were then converted into rasterized format. Our findings indicate that approximately 22% of the lake basin has been designated for feeding dam reservoirs. The impact of precipitation anomalies on the lake's water level was found to be relatively less significant when compared to the increased storage capacity of the dams. Furthermore, the construction of dams prior to 2000 contributed to enhancing the lake's stability during periods of drought. However, the substantial increase in the total storage capacity of dams after 2000 has significantly accelerated the shrinkage process. As a result, it was concluded that any effective rescue plan should prioritize ignoring a considerable portion of the reservoirs' storage capacity by releasing stored water, thereby allowing the lake to attain a stable condition.

Estuaries are the main entry areas of mercury to the marine environment and are important to understand the effect of this contaminant on marine organisms, since it accumulates in the sediments becoming available to enter the food trophic chain. This study aims to determine the environmental variables that mainly influence the spatiotemporal dynamics of total mercury accumulation in sediments of tropical estuaries. Sediment samples were collected from interior and exterior areas of the estuary during the dry and rainy seasons, representing the spatiotemporal gradients of the estuary. The grain size, organic matter content (OM), and total mercury concentration (THg) of the sediment samples were determined. In addition, salinity, temperature, dissolved oxygen, and pH of the water column associated with each sediment sample were assessed. The variations in environmental conditions, OM and THg in sediment were in accordance with a gradient which goes from conditions influenced by fresh water in the inner estuary to conditions influenced by sea water in the outer part of the estuary. The OM and THg in sediments presented similar variation patterns; they were higher in the rainy season than in the dry season and in the interior area of the estuary than in the exterior area. Despite the complex dynamic observed in the distribution and accumulation processes of mercury in sediments, these processes could be modeled from OM and salinity parameters. Due to the correlations found, in the process of accumulation of mercury in sediments the OM could represents the pathway of transport and accumulation of THg, and salinity could represent the influence of the hydroclimatic variations and environmental gradients of the estuary.

This study aims to investigate the presence of SARS-CoV-2 in public spaces and assess the utility of inexpensive air purifiers equipped with high-efficiency particulate air (HEPA) filters for viral detection. Samples were collected from six community-based organizations in underserved minority neighborhoods in Northwest Miami, Florida, from February to May 2022. Reverse transcription–quantitative polymerase chain reaction (RT-qPCR) was used to detect SARS-CoV-2 in air purifier filters and surface swabs. Among 32 filters tested, three yielded positive results, while no positive surface swabs were found. Notably, positive samples were obtained exclusively from child daycare centers. These findings highlight the potential for airborne transmission of SARS-CoV-2 in indoor air, particularly in child daycare centers. Moreover, the study demonstrates the effectiveness of readily available HEPA filters in detecting the virus. Improving indoor ventilation and implementing air filtration systems are crucial in reducing COVID-19 transmission where people gather. Air filtration systems incorporating HEPA filters offer a valuable approach to virus detection and reducing transmission risks. Future research should explore the applicability of this technology for early identification and mitigation of viral outbreaks.