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The number of people served by networked systems that supply intermittent and contaminated drinking water is increasing. In these settings, centralized water treatment is ineffective, while household-level water treatment technologies have not been brought to scale. This study compares a novel low-cost technology designed to passively (automatically) dispense chlorine at shared handpumps with a household-level intervention providing water disinfection tablets (Aquatab), safe water storage containers, and behavior promotion. Twenty compounds were enrolled in Dhaka, Bangladesh, and randomly assigned to one of three groups: passive chlorinator, Aquatabs, or control. Over a 10-month intervention period, the mean percentage of households whose stored drinking water had detectable total chlorine was 75% in compounds with access to the passive chlorinator, 72% in compounds receiving Aquatabs, and 6% in control compounds. Both interventions also significantly improved microbial water quality. Aquatabs usage fell by 50% after behavioral promotion visits concluded, suggesting intensive promotion is necessary for sustained uptake. The study findings suggest high potential for an automated decentralized water treatment system to increase consistent access to clean water in low-income urban communities.

Plastic debris is thought to be widespread in freshwater ecosystems globally 1 . However, a lack of comprehensive and comparable data makes rigorous assessment of its distribution challenging 2 , 3 . Here we present a standardized cross-national survey that assesses the abundance and type of plastic debris (>250 μm) in freshwater ecosystems. We sample surface waters of 38 lakes and reservoirs, distributed across gradients of geographical position and limnological attributes, with the aim to identify factors associated with an increased observation of plastics. We find plastic debris in all studied lakes and reservoirs, suggesting that these ecosystems play a key role in the plastic-pollution cycle. Our results indicate that two types of lakes are particularly vulnerable to plastic contamination: lakes and reservoirs in densely populated and urbanized areas and large lakes and reservoirs with elevated deposition areas, long water-retention times and high levels of anthropogenic influence. Plastic concentrations vary widely among lakes; in the most polluted, concentrations reach or even exceed those reported in the subtropical oceanic gyres, marine areas collecting large amounts of debris 4 . Our findings highlight the importance of including lakes and reservoirs when addressing plastic pollution, in the context of pollution management and for the continued provision of lake ecosystem services. Analysis of plastic debris found in surface waters shows that lakes and reservoirs in densely populated and urbanized regions, as well as those with elevated deposition areas, are particularly vulnerable to plastic contamination.

Tannery effluents contain a diverse blend of chemical, physical, and biological pollutants that threaten environmental quality and public health. This study offers a comprehensive evaluation of pollution profile and associated health risks resulting from untreated tannery wastewater discharges in Naraguta area of Jos, Nigeria. A total of 84 surface water samples were collected over a course of one year. Samples were examined for major physicochemical parameters (like pH, electrical conductivity, total suspended solids, total dissolved solids, total solids, Biochemical Oxygen Demand BOD 5 , and Chemical Oxygen Demand COD) according to American Public Health Association (APHA) and World Health Organization (WHO) methods. Heavy metals (iron and chromium) were also measured using atomic absorption spectrophotometry (AAS), while levels of nutrients (nitrate, sulfate, chloride, and total nitrogen) were analyzed through spectrophotometric and titrimetric methods. Microbial pathogens such as Escherichia coli and helminth eggs ( Ascaris lumbricoides , Hookworm , Trichuris trichiura , and Strongyloides stercoralis ) were detected through multiple-tube fermentation and parasitological concentration methods. Pollution was quantified using established indices, including Geo-Accumulation Index (I_geo), Environmental Hazard Index (EHI), and Pollution Load Index (PLI), using National Environmental Standards and Regulations Enforcement Agency (NESREA) and World Health Organization (WHO) guideline values serving as reference standards. Pollution Index (PI) values were 3-6 times over permissible levels. Contamination Index (CI) rated samples taken from stations downstream were highly polluted based on the cumulative impacts of several contaminants. Geo-Accumulation Index (I_geo), for chromium was as high as 5.06, reflecting “very strong pollution,” while I_geo, for turbidity (3.3) and colour (3.6) reflected a significant anthropogenic contribution. Health hazards were measured by the Health Risk Index (HRI) model, which included Chronic Daily Intake (CDI) and Reference Dose (RfD) models to predict ingestion-based pathways of exposure. Principal Component Analysis (PCA) revealed three principal components that accounted for 85.9% of the total variance, indicating both industrial (anthropogenic) and microbial origins of contamination. These results emphasize the pressing ecological and public health risks posed by ineffective tannery waste management. The study calls for an immediate implementation of stricter effluent discharge controls, investment in modern wastewater treatment systems, and establishment of continuous environmental monitoring programs to prevent long-term exposure and degradation.

The use of water quality indices (WQIs) as a tool to evaluate the status of water quality in rivers has been introduced since the 1960s. The WQI transforms selected water quality parameters into a dimensionless number so that changes in river water quality at any particular location and time could be presented in a simple and easily understandable manner. Although many WQIs have been developed, there is no worldwide accepted method for implementing the steps used for developing a WQI. Thus, there is a continuing interest to develop accurate WQIs that suit a local or regional area. This paper aimed to provide significant contribution to the development of future river WQIs through a review of 30 existing WQIs based on the four steps needed to develop a WQI. These steps are the selection of parameters, the generation of sub-indices, the generation of parameter weights and the aggregation process to compute the final index value. From the 30 reviewed WQIs, 7 were identified as most important based on their wider use and they were discussed in detail. It was observed that a major factor that influences wider use of a WQI is the support provided by the government and authorities to implement a WQI as the main tool to evaluate the status of rivers. Since there is a lot of subjectivity and uncertainty involved in the steps for developing and applying a WQI, it is recommended that the opinion of local water quality experts is taken, especially in the first three steps (through techniques like Delphi method). It was also observed that uncertainty and sensitivity analysis was rarely undertaken to reduce uncertainty, and hence such an analysis is recommended for future studies.

Microplastic particles were quantified in beach transects of the East Frisian islands Spiekeroog and Kachelotplate and in two samples from a tidal flat. Both granules and fibres were present while fragments and polystyrene pellets were completely absent. On the Kachelotplate the highest number of granules (496/10 g sediment) was observed at the high water line while on Spiekeroog a sample from the dune area had the highest value (38/10 g sediment). The tidal flat samples hat 36 and 136 granules/10 g sediment with the higher number being associated with a blue mussel bank. Fibres were more homogeneously distributed and did not show any particular enrichment. In comparison with data from the Belgian coast the total numbers are higher which might be related to the exposure situation of the island beaches.

Open up, share and network information so that marine stewardship can mitigate climate change, overfishing and pollution. Open up, share and network information so that marine stewardship can mitigate climate change, overfishing and pollution.

Protected areas due to their long-term protection are expected to be characterized by good water quality. However, in catchments where arable fields dominate, the impact of agriculture on water pollution is still problematic. In Poland, recently, the fertilization level has decreased, mostly for economic reasons. However, this applies primarily to phosphorus and potassium. In order to evaluate the impact of agriculture on water quality in a protected area with a high proportion of arable fields in the aspect of level and type of fertilization, complex monitoring has been applied. The present study was carried out in Wielkopolska National Park and its buffer zone, which are protected under Natura 2000 as Special Areas of Conservation and Special Protection Areas. The aim of the study were (1) to assess the impact of agriculture, with special attention on fertilization, on groundwater, and running water quality and (2) to designate priority areas for implementing nitrogen reduction measures in special attention on protected areas. In our study, high nitrogen concentrations in groundwater and surface waters were detected in the agricultural catchments. The results demonstrate that in the watersheds dominated by arable fields, high nitrogen concentrations in groundwater were measured in comparison to forestry catchments, where high ammonium concentrations were observed. The highest nitrogen concentrations were noted in spring after winter freezing, with a small cover of vegetation, and in the areas with a high level of nitrogen application. In the studied areas, both in the park and its buffer zone, unfavorable N:P and N:K ratios in supplied nutrients were detected. Severe shortage of phosphorus and potassium in applied fertilizers is one of the major factors causing leaching of nitrogen due to limited possibilities of its consumption by plants.

Microplastics (MPs) have contaminated all compartments of the marine environment including biota such as seafood; ingestion from such sources is one of the two major uptake routes identified for human exposure. The objectives were to conduct a systematic review and meta-analysis of the levels of MP contamination in seafood and to subsequently estimate the annual human uptake. MEDLINE, EMBASE, and Web of Science were searched from launch (1947, 1974, and 1900, respectively) up to October 2020 for all studies reporting MP content in seafood species. Mean, standard deviations, and ranges of MPs found were collated. Studies were appraised systematically using a bespoke risk of bias (RoB) assessment tool. Fifty studies were included in the systematic review and 19 in the meta-analysis. Evidence was available on four phyla: mollusks, crustaceans, fish, and echinodermata. The majority of studies identified MP contamination in seafood and reported MP content , with 26% of studies rated as having a high RoB, mainly due to analysis or reporting weaknesses. Mollusks collected off the coasts of Asia were the most heavily contaminated, coinciding with reported trends of MP contamination in the sea. According to the statistical summary, MP content was in mollusks, in crustaceans, in fish, and in echinodermata. Maximum annual human MP uptake was estimated to be close to 55,000 MP particles. Statistical, sample, and methodological heterogeneity was high. This is the first systematic review, to our knowledge, to assess and quantify MP contamination of seafood and human uptake from its consumption, suggesting that action must be considered in order to reduce human exposure via such consumption. Further high-quality research using standardized methods is needed to cement the scientific evidence on MP contamination and human exposures. https://doi.org/10.1289/EHP7171.

Groundwater arsenic contamination has been a health hazard for West Bengal, India. Oxidative stress to DNA is recognized as an underlying mechanism of arsenic carcinogenicity. A phytochemical, curcumin, from turmeric appears to be potent antioxidant and antimutagenic agent. DNA damage prevention with curcumin could be an effective strategy to combat arsenic toxicity. This field trial in Chakdah block of West Bengal evaluated the role of curcumin against the genotoxic effects of arsenic. DNA damage in human lymphocytes was assessed by comet assay and fluorescence-activated DNA unwinding assay. Curcumin was analyzed in blood by high performance liquid chromatography (HPLC). Arsenic induced oxidative stress and elucidation of the antagonistic role of curcumin was done by observation on reactive oxygen species (ROS) generation, lipid peroxidation and protein carbonyl. Antioxidant enzymes like catalase, superoxide dismutase, glutathione reductase, glutathioneS-transferase, glutathione peroxidase and non-enzymatic glutathione were also analyzed. The blood samples of the endemic regions showed severe DNA damage with increased levels of ROS and lipid peroxidation. The antioxidants were found with depleted activity. Three months curcumin intervention reduced the DNA damage, retarded ROS generation and lipid peroxidation and raised the level of antioxidant activity. Thus curcumin may have some protective role against the DNA damage caused by arsenic.