Microbiological Water Quality Research Articles

Microbiological hazards associated with the use of water in the post-harvest handling and processing operations of fresh and frozen fruits, vegetables and herbs (ffFVH). Part 4 (fresh-cut FVH process water management plan).

Water used in post-harvest handling and processing operations is an important risk factor for microbiological cross-contamination of fruits, vegetables and herbs (FVH). Industrial data indicated that the fresh-cut FVH sector is characterised by process water at cooled temperature, operational cycles between 1 and 15 h, and product volumes between 700 and 3000 kg. Intervention strategies were based on water disinfection treatments mostly using chlorine-based disinfectants. Water replenishment was not observed within studied industries. The industrial data, which included 19 scenarios were used to develop a guidance for a water management plan (WMP) for the fresh-cut FVH sector. A WMP aims to maintain the fit-for-purpose microbiological quality of the process water and consists of: (a) identification of microbial hazards and hazardous events linked to process water; (b) establishment of the relationship between microbiological and physico-chemical parameters; (c) description of preventive measures; (d) description of intervention measures, including their validation, operational monitoring and verification; and (e) record keeping and trend analysis. A predictive model was used to simulate water management outcomes, highlighting the need for water disinfection treatments to maintain the microbiological quality of the process water and the added value of water replenishment. Relying solely on water replenishment (at realistic feasible rates) does not avoid microbial accumulation in the water. Operational monitoring of the physico-chemical parameters ensures that the disinfection systems are operating effectively. Verification includes microbiological analysis of the process water linked to the operational monitoring outcomes of physico-chemical parameters. Although Escherichia coli and Listeria spp. could be indicators for assessing water quality, food business operators should set up and validate a tailored WMP to identify physico-chemical parameters, as well as microbial indicators and their threshold levels, as performance standards for maintaining the fit-for-purpose microbiological quality of the process water during post-harvest handling and processing operations.

Microbiological hazards associated with the use of water in the post-harvest handling and processing operations of fresh and frozen fruits, vegetables and herbs (ffFVH). Part 3 (Fresh-whole FVH process water management plan).

Water used in post-harvest handling and processing operations is an important risk factor for microbiological cross-contamination of fruits, vegetables and herbs (FVH). Industrial data indicated that the fresh-whole FVH sector is characterised by very variable operational cycle duration (between 8 and 900 h), large product volumes (e.g. more than 6000 tonnes) and process water at 2.8-25.0°C. Intervention strategies were based on water disinfection treatments, mostly using chlorine-based disinfectants. Water replenishment was not observed within studied industries. The industrial data, which included 29 scenarios were used to develop a guidance for a water management plan (WMP) for the fresh-whole FVH sector. A WMP aims to maintain the fit-for-purpose microbiological quality of the process water and consists of (a) identification of microbial hazards and hazardous events linked to process water; (b) establishment of the relationship between microbiological and physico-chemical parameters; (c) description of preventive measures; (d) description of intervention measures, including their validation, operational monitoring and verification; and (e) record keeping and trend analysis. A predictive model was used to simulate water management outcomes, highlighting the need for water disinfection treatments to maintain the microbiological quality of the process water and the added value of water replenishment. Relying solely on water replenishment (at realistic feasible rates) does not avoid microbial accumulation in the water. Operational monitoring of the physico-chemical parameters ensures that the disinfection systems are operating effectively. Verification includes microbiological analysis of the process water linked to the operational monitoring outcomes of physico-chemical parameters. Food business operators (FBOps) should set up and validate a tailored WMP to identify physico-chemical parameters, as well as microbial indicators and their threshold levels, as performance standards for maintaining the fit-for-purpose microbiological quality of the process water during post-harvest handling and processing operations.

Microbiological hazards associated with the use of water in the post-harvest handling and processing operations of fresh and frozen fruits, vegetables and herbs (ffFVH). Part 5 (Frozen FVH process water management plan).

Water used in post-harvest handling and processing operations is an important risk factor for microbiological cross-contamination of fruits, vegetables and herbs (FVH). Industrial data indicated that the frozen FVH sector is characterised by operational cycles between 8 and 120 h, variable product volumes and no control of the temperature of process water. Intervention strategies were limited to the use of water disinfection treatments such as peroxyacetic acid and hydrogen peroxide. Chlorine-based disinfectants were not used, and water replenishment was not observed within studied industries. The industrial data, which included 13 scenarios, were used to develop a guidance for a water management plan (WMP) for the frozen FVH sector. A WMP aims to maintain the fit-for-purpose microbiological quality of the process water and consists of: (a) identification of microbial hazards and hazardous events linked to process water; (b) establishment of the relationship between microbiological and physico-chemical parameters; (c) description of preventive measures; (d) description of intervention measures, including their validation, operational monitoring and verification; and (e) record keeping and trend analysis. A predictive model was used to simulate water management outcomes, highlighting the need for water disinfection treatments to maintain the microbiological quality of the process water and the added value of water replenishment. Relying solely on water replenishment (at realistic feasible rates) does not avoid microbial accumulation in the water. Operational monitoring of the physico-chemical parameters ensures that the disinfection systems are operating effectively. Verification includes microbiological analysis of the process water linked to the operational monitoring outcomes of physico-chemical parameters. Food business operators should set up and validate a tailored WMP to identify physico-chemical parameters, as well as microbial indicators and their threshold levels as performance standards for maintaining the fit-for-purpose microbiological quality of the process water during post-harvest handling and processing operations.

Microbiological hazards associated with the use of water in the post-harvest handling and processing operations of fresh and frozen fruits, vegetables and herbs (ffFVH). Part 2 - A dynamic mass balance model for handling and processing operations in ffFVH using water.

A dynamic mass balance model was developed to simulate contamination dynamics in the process water of fresh and frozen fruits, vegetables and herbs (ffFVH) during processing and handling operations. The mass balance relates to the flux of water and product in a wash tank and the number of microbial cells released in the water, inactivated by the water disinfectant or transferred from the water back to the product. Critical variables describing microbial dynamics in water are: (i) the chemical oxygen demand (COD), as an indicator of the concentration of organic matter; (ii) free chlorine (FC) and particularly its antimicrobial fraction, hypochlorous acid (HOCl); and (iii) the microbial population levels. Model parameters include: (i) the dilution rate of the process water, representing the speed of system saturation, equal to the water flux divided by the tank volume; (ii) the transfer rates of total bacterial counts (TBC) and COD from product to water; and (iii) the specific inactivation rate of microorganisms due to HOCl. The protective effect of COD on microbial cells against FC is encompassed in the inactivation rate. HOCl is expressed as a function of temperature, pH and total chlorine. The model can simulate 'what if scenarios', based on user-defined process-specific and product/microorganism-specific parameters through a web R-based application. This model can help food business operators when selecting intervention strategies and conditions to maintain the microbiological quality of the process water or identify conditions that represent poor or proper water management practices. Testing alternative model structures and collecting data about operational conditions of handling and/or processing operations, microbial dynamics and the magnitude of the product-specific protective effect on microorganisms are recommended to improve the application of the model.

The microbiological quality of bathing waters in the city of Tangier

The microbiological quality of bathing waters in the city of Tangier

Microbiological and physicochemical water quality assessments of the Upper Basin Litany River, Lebanon.

The Litany River has encountered severe environmental pollution. This study focused on assessing the pollution level in the upper basin of the Litany River by monitoring seasonal variation of water quality and testing physicochemical parameters and microbial qualities. A total of 72 freshwater samples were taken from six sites for 1 year during the four seasons. The microbiological parameters included total coliform, fecal coliform, and Escherichia coli counts. The physicochemical parameters comprised pH, total dissolved solids, nitrate, sodium, potassium, biochemical oxygen demand, chemical oxygen demand, total nitrogen, and total phosphorus. The microbiological quality of samples was evaluated by comparing the fecal pollution indicators loads to the SEQ-EAUX2003 standard for irrigation, and the physicochemical analyses were assessed according to Lebanese Standards Institution (LIBNOR) NL161: 2016 and the World Health Organization (WHO) Guidelines for Water Quality. The results revealed that most physicochemical parameters are not within the permitted limit of LIBNOR and WHO, especially in sites S2, S3, and S6 during the dry seasons. The pH ranged between 6 and 8.16. The total dissolved solids reached 1948 mg/L. The nitrate, sodium, and potassium ranged between 0 and 253 mg/L. The total nitrogen and total phosphorous reached 103 and 5.16 mg/L, respectively. The chemical oxygen demand reached 2210 mg/L, and the biochemical oxygen demand reached 732 mg/L. Concerning the microbiological analysis, fecal pollution was detected in all sites during all seasons, with detectable higher values during the dry seasons, and all samples were considered to be non-conforming, with significant spatiotemporal variation of most parameters. Our results highlight the need to take measures to prevent the high level of pollution. This could be achieved by monthly water quality monitoring of the upper basin and introducing appropriate guidelines to detect pathogens and toxic chemicals that affect the entire ecosystem and lead to severe public health issues.

Physico-Chemical and Microbiological Quality of the Surface Water of the Nostoc Commune of the Andean Communities of Huancavelica, Peru

Objective: The purpose was to evaluate the physicochemical and microbiological quality of surface water from the Nostoc commune of Andean communities in Huancavelica-Peru, and to compare its variation in relation to its distribution and environmental conditions. Theoretical Framework: Surface water quality depends on anthropogenic factors. The physico-chemical and microbiological surface water quality indicators of the Nostoc commune are important for environmental monitoring, biomass production and social economic livelihoods. Method: Samples of surface water from streams and ponds were considered as biological material. The physicochemical and microbiological analyses were determined according to the protocol and recommendations established in the Standard Methods for the Examination of Wastewater of APHA (2012) and ECA (2017). Results and Discussion: The results revealed that the physicochemical and microbiological parameters of surface waters of streams and ponds inhabited by Nostoc commune meet the guidelines established by ECA and APHA, with variations to their geographical distribution and environmental conditions. Meteorologically, Nostoc commune is common at altitudes between 4240 and 5877 masl, with temperatures of 4-14°C and relative humidity of 20-60% varying between January and April. Research Implications: The study shows the surface waters of the Nostoc commune to be unsuitable for agricultural and human use. It is crucial for public and environmental health as a balancer of surface water quality. Originality: It offers unprecedented contributions to the literature on the quality of the surface water of the Nostoc commune habitat. The relevance and value of this algae as a viable source of water utilization for agricultural and public health purposes is evident.

Microbiological water quality assessment of swimming pools and jacuzzis in Northern Greece: a retrospective study.

Swimming pools and jacuzzis can pose significant public health risks as potential sources of infections. The present study aimed to evaluate the prevalence and concentration of microbiological indicators in recreational water facilities in Thessaloniki, Northern Greece, focusing on their hygiene status before and after the COVID-19 pandemic. Between January 2018 and December 2022, 1114 water samples were analyzed by the regional Water Hygiene Laboratory at Aristotle University of Thessaloniki, using standardized ISO methods. Jacuzzis exhibited the highest microbial contamination, particularly for Pseudomonas aeruginosa (19.7%), while indoor adult pools showed the lowest. Overall, P. aeruginosa was found in 12.4% of samples, with the highest concentrations in jacuzzis (median: 30 CFU/100 ml). Significant seasonal variations were identified in the prevalence of total microbial flora (p < 0.001) and total coliforms (p = 0.03), as well as in the concentration of residual chlorine (p = 0.023). During the COVID-19 pandemic, microbial prevalence decreased across facilities. We concluded a strong compliance with Greek and international microbiological standards. The decline in microbial prevalence overtime likely reflects the impact of the strict hygiene measures implemented during the pandemic. These findings highlight the importance of maintaining rigorous hygiene practices to protect public health.

Assessment of surface and groundwater quality in the Ctalamochita River basin, Argentina: hydrogeochemical characteristics and exploratory data analysis.

Freshwater and groundwater are important resources for the drinking water supporting agricultural and livestock activities in the Córdoba province, Argentina. The aim of this study was to assess the physicochemical and microbiological quality of surface water (n = 14) and groundwater (n = 17) sites in the middle-lower basin of the Ctalamochita River (Córdoba, Argentina) for human and animal consumption. A total of 18 physicochemical and five microbiological parameters were evaluated to determine the hydrogeological characteristics of both water resources and their suitability for human and animal consumption using the Water Quality Index (WQI). The results indicated that Na+ and HCO3- were the dominant cation and anion, respectively, in both water resources. Physicochemical and microbiological parameters values were compared with national and international guidelines. The WQI showed that groundwater samples exhibited poorer quality when compared to surface waters for human consumption, primarily due to elevated concentrations of major ions and the presence of total coliforms and Pseudomonas aeruginosa. Meanwhile, the WQI for animal consumption indicated that both surface and groundwater samples were suitable for this purpose. The Piper diagram showed that most of the surface water samples were classified as Na+-Cl--HCO3-, while groundwater samples were classified as Na+-HCO3-. This classification highlights the hydrogeochemical differences between the two water resources. TheGibbs diagram indicates that the chemical composition of both surface and groundwater sources is primarily controlled by processes of rock-water interaction and evaporation. The findings of this study will facilitate the development of a proactive plan to safeguard and sustain water resources in the middle-lower basin of the Ctalamochita River. This can be achieved through the implementation of preventive strategies and the introduction of innovative policies.

Addressing underestimation of waterborne disease risks due to fecal indicator bacteria bound in aggregates.

This study aims to identify and address significant limitations in current culture-based regulatory methods used for monitoring microbiological water quality. Specifically, these methods' inability to distinguish between planktonic forms and aggregates containing higher bacterial loads and associated pathogens may lead to a severe underestimation of exposure risks, with critical public health implications. We employed a novel methodology combining size fractionation with ALERT (Automatic Lab-in-a-vial E.coli Remote Tracking), an automated rapid method for comprehensive quantification of culturable fecal indicator bacteria (FIB). Our findings reveal a substantial and widespread presence of aggregate-bound indicator bacteria across various water matrices and geographical locations. Comprehensive bacterial counts consistently exceeded those obtained by traditional methods by significant multiples, such as an average of 3.4×at the Seine River 2024 Olympic venue, and occasionally up to 100×in irrigation canals and wastewater plant effluent. These results, supported by microscopic and molecular analyses, underscore a systematic bias in global water safety regulatory frameworks. Our research demonstrates the inadequacy of traditional culture-based techniques in assessing microbiological risks posed by aggregate-bound FIB and associated pathogens, particularly in water matrices affected by FIB-rich fecal particles from recent sewer overflows or sediment, which can carry higher infectious risks. Incorporating comprehensive FIB analysis techniques, including molecular methods and rapid culture-based approaches as shown in this study, offers a promising and effective solution to these risk assessment limitations.

In-vitro and in-vivo assessment of the bactericidal potential of peracetic acid and hydrogen peroxide disinfectants against A. hydrophila infection in Nile tilapia and their effect on water quality indices and fish stress biomarkers

This study aimed to assess the in vitro and in vivo disinfectant potential of peracetic acid (PAA) (1 mg/L) and hydrogen peroxide (H2O2) (20 mg/L) on the physicochemical and microbiological water quality parameters of fish aquaria, the microbial density of Nile tilapia muscular tissue, fish hepatic cortisol levels, and antioxidant biomarkers. In vitro, PAA and H2O2 reduced A. hydrophila colony viability by 5 log units after 30 and 5 min of contact time, respectively. PAA and H2O2 were added to aquaria water twice a week for the three-week experiment. Increased fish escape reflexes were observed only in the PAA group, which returned to normal within 10 min. No mortalities were reported in either the PAA or H2O2 groups. An in vivo experimental challenge with a pathogenic strain of A. hydrophila revealed a 20% reduction in mortality in the PAA group, with no mortalities in the H2O2 group. Cortisol levels and antioxidant markers were measured to assess the impact of PAA and H2O2 on fish health. Cortisol levels in the PAA and H2O2 groups were significantly higher than in the control group after disinfectant exposure, but they progressively returned to normal. A significant reduction in superoxide dismutase (SOD) and catalase (CAT) activity, along with considerably higher glutathione peroxidase (GPx) and malondialdehyde (MDA) enzymatic activity, was observed in the PAA and H2O2 groups compared to the control group. A substantial increase in total antioxidant capacity (TAC) was recorded in the PAA group. Physicochemical analyses revealed reduced pH and increased dissolved oxygen levels in the PAA and H2O2 groups. Microbiological analyses showed a significant reduction in bacterial density in water by 64% and 76% after 30 min of exposure to PAA and H2O2, respectively, with a non-significant increase in microbial count after bacterial challenge. Additionally, aerobic bacterial count, Aeromonas spp., and psychotropic bacterial count in fish muscle showed a significant reduction in the H2O2 group compared to the PAA and control groups before and after infection. The study concludes that regular application of PAA and H2O2 can temporarily reduce bacterial load in aquaria and fish muscle, regulate stress responses, and improve fish health by reducing A. hydrophila-induced infections and improving survival.

Multivariate statistical analysis as a tool for monitoring drinking water sources in an Atlantic Rainforest Conservation Unit.

Water quality monitoring is paramount in identifying and mitigating pollution sources, protecting aquatic ecosystems, and ensuring safe water for human and wildlife consumption. This study is aimed at evaluating the quality of drinking water sources in three communities located in a Sustainable Use Conservation Unit in the municipality of Mangaratiba, Rio de Janeiro, Brazil, employing a multivariate statistical analysis. A total of 161 water samples were collected from January to December 2022, encompassing 32 surface water and 129 tap water samples. Physicochemical parameters were determined in situ employing a Horiba U50 multiparameter probe. The samples were stored and transported at 4°C to the laboratory for microbiological analyses concerning total coliforms and Escherichia coli using a commercial enzymatic test. All samples contained coliforms, while E. coli were detected in 87% of the samples. The multivariate analysis indicated that the microbiological water quality in sampling region R2 was influenced by rainy periods and that, in general, the water quality within R3 was the most affected by the transport of solids to the water sources. The statistical methods applied herein aided in characterizing the study areas and detecting points of attention regarding physicochemical and microbiological parameters that significantly influence the water quality of each sampling point. Representative points for each study region were identified and may be employed for future monitoring and prevention actions.

Characterization and evaluation of physiochemical and microbiological water quality parameters in Palestinian schools: a case study from Central Hebron Directorate

Characterization and evaluation of physiochemical and microbiological water quality parameters in Palestinian schools: a case study from Central Hebron Directorate

The microbiological quality of bottled and tap water: Risks and regulations

The microbiological quality of bottled and tap water: Risks and regulations

Enhancing infection control in dialysis at a resource limited public healthcare institute: A cross-sectional study on microbiological quality assessment of dialysis water and dialysate

PurposeTo evaluate the microbiological quality of dialysis water and dialysate samples from hemodialysis units at a tertiary care government hospital and to assess the use of culture, endotoxin and periodicity of testing these assays to guide the actions of monitoring the quality of hemodialysis fluids, implement preventive and corrective actions, and improve the safety and outcomes of the dialysis process. MethodsA cross-sectional study was conducted at a 250-bedded super-specialty government hospital with a 24/7 hemodialysis unit equipped with 40 dialysis machines. Dialysis water and dialysate samples were collected monthly and analysed for microbial contamination and endotoxin levels as per AAMI guidelines. Bacterial cultures were done using Reasoner's Agar plates, and endotoxin analysis was performed using gel clot assay. Interpretation of results was based on predefined thresholds. ResultsAmong the 740 samples processed for microbial culture 19.6 % and 80.4% were unacceptable and acceptable respectively.Among the acceptable samples 10.5 % were at action level. At the end of 2 days of incubation, 15.2%dialysis water samples and 5.1%dialysate samples had unacceptable levels of bacterial colonies and at 5days additional 10.6 % dialysis water samples and 7.7%dialysate samples were unacceptable. 21.5 % of the samples tested for endotoxin had unacceptable levels. ConclusionsRegular monitoring of water quality in government healthcare hemodialysis units is crucial for quality of care, timely preventive and corrective actions for mitigating adverse outcomes. Processing cultures for 5–7 days is essential for detecting all contaminated specimens. While there might be a link between endotoxin levels and bacterial contamination, both endotoxin testing and bacterial culture independently are vital for evaluating water quality in dialysis settings. A comprehensive approach integrating various testing methods is necessary to uphold patient safety and enable necessary improvements.

Estimation of soil loss using RUSLE model and GIS tools: Case study in the Jucusbamba Micro-Watershed (Amazonas, NW Peru)

Human activities have intensified soil erosion globally, negatively impacting the physical, chemical, and microbiological quality of water and soil. This study estimated soil loss in the Jucusbamba Micro-Watershed (Amazonas, northwestern Peru) using the Revised Universal Soil Loss Equation (RUSLE) integrated with Geographic Information Systems (GIS) and remote sensing (RS) data. Meteorological data, soil maps, digital elevation models, and land cover and use maps were integrated into a GIS environment to predict the spatial distribution of erosion. The results showed five classes of soil loss severity: slight (93.34%), moderate (3.94%), high (1.82%), very high (0.61%), and severe (0.29%). Areas with high, very high, and severe erosion levels were mainly located in the middle and lower parts of the micro-watershed. The average annual soil loss was estimated at 23.24 t/ha/year. The information obtained is crucial for the formulation of soil management plans and programs to address erosion problems in the Jucusbamba River Micro-Watershed. Future research should focus on validating these models through field studies and implementing soil conservation practices based on these findings. Keywords: Amazonas, hydrology, RUSLE model, water erosion map, watershed.

Microbiological Quality of Coconut Water Sold in the Grande Vitória Region, Brazil, and Phenogenotypic Antimicrobial Resistance of Associated Enterobacteria.

This study aimed to evaluate the microbiological quality of coconut water sold from street carts equipped with cooling coils or refrigerated at bakeries in the Grande Vitória Region, Brazil. Additionally, it assessed the phenotypic and genotypic antimicrobial resistance profiles of isolated enterobacteria. The results indicated that coconut water sold at street carts had lower microbiological quality compared to refrigerated samples, as evidenced by significantly higher counts of mesophilic microorganisms. Using MALDI-TOF, the following opportunistic pathogens were identified: Citrobacter freundii, Enterobacter bugandensis, E. kobei, E. roggenkampii, Klebsiella pneumoniae, and Kluyvera ascorbata. Three isolates-E. bugandensis, K. pneumoniae, and K. ascorbata-were classified as multidrug-resistant (MDR). Widespread resistance to β-lactams and cephalosporins was detected, and some isolates were resistant to quinolones, nitrofurans, and phosphonic acids. The gene blaCTX-M-2 was detected in C. freundii, E. bugandensis, E. kobei, and K. ascorbata. However, genes blaNDM, blaKPC, blaCMY-1, and blaCMY-2 were not detected in any isolate. The findings underscore the need to enhance good manufacturing practices in this sector to control the spread of antimicrobial resistance (AMR). To our knowledge, this is the first study documenting the presence of potentially pathogenic enterobacteria in coconut water samples and their associated phenotypic and genotypic AMR profiles.

Efficiency of EMB Medium Combined with MALDI-TOF in Isolating and Identifying Coliform Lactose Fermenters and Non-Lactose Fermenters from Wastewater

In Côte d'Ivoire, the sewer network is largely underdeveloped, resulting in the absence or incompleteness of sanitation infrastructure in many urban and rural areas. This lack of infrastructure leads to untreated wastewater being frequently discharged into rivers and other sources of drinking water. The contamination of water sources by untreated wastewater spreads waterborne diseases, which particularly affect children and vulnerable populations. Coliforms, as key indicators of the microbiological quality of water, play a crucial role in assessing health risks. The presence and diversity of these coliforms can provide insights into the extent of water contamination and the potential health risks to the population. This study focuses on the diversity of lactose-fermenting and non-lactose-fermenting coliforms in the wastewater of Abidjan. The objective is to use MALDI-TOF mass spectrometry for the rapid and accurate identification of these coliforms, thereby providing a detailed understanding of the microbiological quality of wastewater. The study aims to identify the predominant coliform species present in the wastewater and assess their potential impact on public health. Out of 80 wastewater samples collected from various locations in Abidjan, a preponderance of lactose-fermenting coliforms was found. The most frequently identified species were Klebsiella pneumoniae and Escherichia coli. The results showed that these species were present in significantly higher numbers compared to non-lactose-fermenting coliforms. The use of MALDI-TOF mass spectrometry allowed for rapid and precise identification of the coliforms, facilitating a comprehensive analysis of the microbiological quality of the wastewater. These findings underscore the urgent need for improved wastewater management strategies in Abidjan and similar urban settings in Côte d'Ivoire. The high prevalence of lactose-fermenting coliforms, particularly Klebsiella pneumoniae and Escherichia coli, in untreated wastewater poses significant public health risks. Effective wastewater treatment and management are essential to protect public health, reduce the spread of waterborne diseases, and limit the development of antimicrobial resistance. Implementing such measures will require coordinated efforts from local authorities, public health officials, and the community to ensure safe and sustainable water practices.

Exploring the nexus between water quality and land use/land cover change in an urban watershed in Uruguay: a machine learning approach.

The expansion of urban areas contributes to the growth of impervious surfaces, leading to increased pollution and altering the configuration, composition, and context of land covers. This study employed machine learning methods (partial least square regressor and the Shapley Additive exPlanations) to explore the intricate relationships between urban expansion, land cover changes, and water quality in a watershed with a park and lake. To address this, we first evaluated the spatio-temporal variation of some physicochemical and microbiological water quality variables, generated yearly land cover maps of the basin adopting several machine learning classifiers, and computed the most suitable landscape metrics that better represent the land cover. The main results highlighted the importance of spatial arrangement and the size of the contributing watershed on water quality. Compact urban forms appeared to mitigate the impact on pollutants. This research provides valuable insights into the intricate relationship between landscape characteristics and water quality dynamics, informing targeted watershed management strategies aimed at mitigating pollution and ensuring the health and resilience of aquatic ecosystems.

Microbial Health Risks of Cryptosporidium parvum and Giardia lamblia in Tropical Coastal Water in Araromi, Nigeria.

Giardia and Cryptosporidium are enteric protozoa that can cause a variety of gastrointestinal diseases, especially in vulnerable people like children, the elderly, and those with impaired immune systems. In order to ascertain the microbiological quality of the recreational water from Araromi Beach in Ilaje Local Government Area, Ondo State, Nigeria. This risk assessment is of great significance to human health protection against waterborne diseases. The aim of this study was to determine the microbial quality of recreational water from Araromi Beach in Ilaje Local Government Area, Ondo State, Nigeria. Microscopic examination of Cryptosporidium and Giardia oocysts were done. Results revealed maximum occurrence of Cryptosporidium parvum (20 oocysts/100 mL) of water sample in the month of April and maximum occurrence of Giardia lamblia (300 cysts/100 mL) of water sample in the month of June. Additionally, according to Kolmogorov-Smirnov tests for normalcy Ho =0.05, Giardia lamblia and Cryptosporidium parvum were not regularly distributed in the water samples collected from the beach throughout the study period. The average likelihood of contracting Giardia lamblia and Cryptosporidium parvum infections after consuming 100 mL of beach water was 0.96 and 0.35, respectively. The risks of infection associated with Cryptosporidium parvum was lower than those associated with Giardia lamblia in water from the beach, but were both above the acceptable risk limit of 10-4. The results of this study indicate that Giardia and Cryptosporidium may represent serious health hazards to people who engage in aquatic activities. Adopting a comprehensive strategy that includes regular inspections, enhanced detection techniques, and the prevention of aquatic environment pollution may provide clean and safe recreational water for all, thereby safeguarding the public's health.