Abstract The amount of medical waste generated has increased enormously since the COVID-19 outbreak. An incineration process is the main method that is usually used to treat this waste causing an increase in both medical waste bottom ash (MWBA) and medical waste fly ash (MWFA). In this work, the physical and chemical characteristics of MWFA and MWBA were reviewed. This ash contains high levels of polychlorinated dibenzo-p-dioxin (PCDD), dibenzofurans (PCDFs), and heavy metals. Furthermore, medical waste ash appears to have high leachability in the toxicity characteristics leaching procedure (TCLP) test and the European standard test (EN 12457). Owing to its toxicity, medical ash can be treated using various methods prior to disposal based on the covered review. These techniques include chemical, supercritical fluid, cement-based, melting, microwave, and mechanochemical techniques. The shortcomings of some of these treatment methods have been identified, such as the emission of high levels of chlorine from the melting technique, limited applications of the flotation method on the industrial scale, long-term stability of leachate treated by cement-based methods that have not been confirmed yet, and high energy consumption in the supercritical technique. This review also covers possible applications of medical waste ash in cement production, agriculture, and road construction.

Abstract The improved water, sanitation and hygiene (WASH) facilities in water-scarce areas is one of the most important barriers to improving the standards of people's life, which is even worse in a locality with forcibly displaced people (e.g., nearly 1 million Rohingya refugee in Bangladesh). In attempting to understand the extent of vulnerability and risks of WASH facilities, their impacts, and adaptive practices in the communities, an exploratory study has been carried out in five selected camps (13, 15, 16, 24 and 27) in Cox's Bazar, Bangladesh. Examination of water facilities shows that households in camps 13, 15 and 16 suffered from an adequate supply of water during summer as there is no direct access to surface water from adjacent water reservoirs, while camps 24 and 27 have such facilities. The frequency of water shortage for drinking purposes in camps 13, 15 and 16 was not so severe like camps 24 and 27. Drinking water collectors had to spend 3–5 h in waiting queues. All latrines were communal/shared latrines, which made users feel uncomfortable and vulnerable. This study implies that WASH facilities need to be reinforced, and community sensitization on WASH behavior needs to be strengthened to reduce WASH-related health hazards.

Abstract The specific contributions of the different bacterial flora during the biological treatment of slaughterhouse effluents remain unclear. The objective of this study is to identify the different microbial flora which mainly contribute to the efficiency of the biodegradation of the organic, nitrogenous and phosphate loads contained in the slaughterhouse effluent during its biological treatment. To achieve this, the effluent to be treated was sampled from three slaughterhouses in the city of Ngaoundéré (Cameroon). The various effluents underwent a physicochemical and microbiological characterization. The effluent was subjected to biological treatment. The biodegradation process (biological treatment) took place in two reactors, each operating in batch. One of the two reactors was supplied with oxygen (aeration). The effluent being treated underwent a physicochemical and microbiological characterization for 30 days. The results obtained show organic matter and ammonium contents >1,000 mgO2/L in each of the three effluents. Bacillus cereus (69 × 108 CFU/mL), Pseudomonas aeruginosa (201 × 107 CFU/mL) and Yeasts (101 × 106 CFU/mL) globally constitute the majority of microbial groups among the seven microorganisms identified in the effluents of the three slaughterhouses. There is no real oxygenation effect of the medium on the growth of the three microbial flora during the treatment.

Abstract Swimming in pools is a popular and healthy recreational activity. However, potential adverse health effects from disinfection byproduct (DBP) exposure in pool water are concerning. This study evaluated how such DBP exposure affects the respiratory system. DBP exposure was simulated with an animal-specific pool environment model. Experimental animals were exposed to DBPs for a specified duration and frequency over 4 weeks. The wet and dry weights of murine lungs were measured, with no significant differences observed. There were no significant differences in IL-2, IL-4, IL-10, and interferon-γ levels. However, IL-6 expression decreased in the experimental group. To investigate the effects of DBP exposure on immune cell response, various samples, such as bronchoalveolar lavage fluid, lymph nodes, spleen, and thymus, were collected for T-cell isolation and fluorescence-activated cell sorting. Asthma-related blood cell distribution was analyzed using a complete blood count test; no significant differences were found. Thus, DBP exposure through this model did not induce substantial lung tissue damage, major alterations in cytokine expression (besides IL-6), significant immune cell responses, or changes in asthma-associated blood cell distribution. However, considering earlier results, future studies should focus on specific types, intensity, and duration of exercise that could affect DBP exposure-related immune-inflammatory responses.

Abstract A risk-based approach is recognised worldwide as the most reliable means for the provision of safe drinking water. Efficient implementation of the water safety plan (WSP) approach, recommended by the World Health Organization (WHO), is facilitated by an auditing framework. In Hungary, development of WSPs is a legal obligation for water suppliers. WSPs are subject to a two-stage regulatory audit, a consultative central technical audit and a formal local audit. In 2019, a survey was conducted in cooperation with WHO to evaluate audit experiences of over 1,200 WSPs. Recommendations from the central audit significantly improved coherence and compliance of WSPs, confirming the efficiency of the dual approach. The use of a WSP template provided by the national authority further increased consistency and reduced time and work demand of the audit. Both water suppliers and public health authorities indicated a need for further capacity building on WSP development and auditing. The main challenge for water suppliers is the identification and risk assessment of hazards associated with the water source and distribution within premises. The recast European Union drinking water regulation is expected to accelerate the uptake of WSP and strengthen linkages to water catchment management and water safety in buildings.

Abstract The free-living amoeba Naegleria fowleri (Nf) inhabits soil and natural waters worldwide: it is thermophilic and thrives at temperatures up to 45 °C and in a multitude of environments. Three deaths in Louisiana were attributed to primary amoebic meningoencephalitis (PAM) caused by Nf infection in 2011 and 2013. Following these incidents, public water systems are now monitored for the presence of Nf in Louisiana. From 2014 to 2018, 29% (27/93) of samples collected showed positive for Nf and 68% (63/93) showed all thermophilic amoeba culture. Ten raw water sources and 17 distribution system water tested positive. The year 2017 showed the highest number of samples with Nf (n = 10) followed by nine samples in 2015. As climate change increases surface water temperatures, continued testing for Nf prevalence will be an important facet of water monitoring and will need to extend into locations farther north than the current most common range.

Abstract The extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is becoming a global public health concern. More comprehensive surveillance of β-lactam resistance in E. coli would improve monitoring strategies and control resistance transmission in contaminated environments. This study investigated the prevalence of β-lactamase genes in E. coli isolated from the Seven Crater Lakes in San Pablo, Laguna, Philippines. Water samples from lakes were collected for the isolation of E. coli (n = 846) and molecular characterization by detecting the presence of the uidA gene. The isolates were then tested for the presence of β-lactamase genes using PCR. Among the screened genes, blaAmpC was the most dominant (91%). Other β-lactamase genes such as blaTEM, blaSHV, and blaCTXM were also detected with percentage occurrence of 34, 5, and 1%, respectively. Multiple genes within individual isolates were also observed, wherein blaTEM/AmpC was the most prevalent gene combination. Moreover, a significant negative correlation between blaAmpC with blaSHV and blaCTXM was depicted in this study. Overall, these findings demonstrate the presence of β-lactamase genes in E. coli in the Seven Crater Lakes of San Pablo and can be used in developing effective strategies to control antibiotic resistance in environmental waters.

Abstract Cryptosporidium spp. are protozoan parasites of significant health importance found in environmental waters globally. Four commercially available Cryptosporidium-specific immunomagnetic separation (IMS) kits used in various water sample matrices were analysed and compared. Beads were characterised by flow cytometry and tested for the recovery efficiencies for oocysts spiked into different matrices: river water sediment, clay sample, and filter backwash sample. Results showed that Dynabeads™ Cryptosporidium and Waterborne Crypto-Grab™ kits contained immunoglobulin IgM antibody-coated beads. In contrast, the BioPoint CryptoBead and the TCS Isolate kits contained immunoglobulin IgG antibody-coated beads. BioPoint CryptoBead was significantly coated with more antibodies and were able to capture oocysts more rapidly compared to the other beads. Recovery efficiencies of Dynabeads™, TCS Isolate® beads, and BioPoint CryptoBead ranged from 55 to 93% when tested against different sample matrices, with BioPoint CryptoBead resulting in the highest at 93% in reagent-grade water and Dynabeads™ at 55%, the lowest against clay samples. The Waterborne beads did not perform well on any samples, with recovery efficiencies ranging from 0 to 8%. Fluorescence microscopy analyses showed that both the IMS method and the sample matrix processed affect the quality of the membranes, with the cleanest samples for microscopy examination observed from BioPoint CryptoBead.

Abstract Different species of free-living amoeba (FLA) have been abundantly isolated in harsh environmental conditions such as hot springs and brackish water. The present study aimed to isolate, genotype, and evaluate the pathogenicity of FLAs in Qom Roud, a large river, in the centre of Iran. About 500 mL of water samples (n = 30) were collected from each sampling site and were investigated for the presence of FLAs using morphological and molecular characters. Genotype identification was performed using DNA sequencing and a phylogenetic tree was constructed with the MEGA X software. The pathogenic potential of all positive isolates was evaluated using the tolerance ability test. Morphological and molecular analysis indicated that 14 (46.66%) and two (6.66%) water samples were positive for Acanthamoeba species and Vahlkampfiidae, respectively. According to sequence analysis, Acanthamoeba isolates related to the T4 genotype and Vahlkampfiidae sequences were similar to Naegleria philippinensis. In the next step, thermo- and osmotolerance tests indicated four Acanthamoeba strains are extremely pathogenic. Our data showed the presence of potentially pathogenic Acanthamoeba T4 genotype and N. philippinensis in the super harsh Qom Roud. Contamination of water with virulent T4 genotype of Acanthamoeba may pose risk factors for contact lens users, children, and immunocompromised people.

Abstract The study aims to understand the relationship of childhood diarrhoea (under-five children) with water, sanitation and hygiene factors in the light of other contextual factors in an urban setting in the district of Hooghly in West Bengal, India. This primary study was carried out by SIGMA Foundation, Kolkata from 4 to 24 January 2023 across 404 households having at least one under-five child. The findings suggested that the water score was ‘good’ in 85.1% of the households whereas the hand hygiene score was ‘good’ in 14.6% of households. More than 90% of the households had piped water supply. Less than half of them treated water before consumption among which 45.3% used cloths for straining water. 59.2% of the caregivers followed safe disposal of child's faeces. 66.8% of households had no handwashing arrangement, and 30.5% had taps and wash basins for handwashing. 20.3% of the under-five children had suffered from diarrhoea in the last month before the survey and its prevalence was higher in children aged 12–23 months. Multivariate results suggested diarrhoea prevalence was lower in households that were pucca and had good water and hand hygiene scores, lower in children that had received iron fortification and whose caregivers followed safe child's stool disposal.