drinking water

Despite technological advancements, heavy metal concentrations in water sources remain above the safe limits set by regulatory standards worldwide. Contaminated drinking water containing heavy metals poses significant public health concerns globally.

This study aims to examine the non-carcinogenic and carcinogenic risks for adults and children exposed to chromium (Cr) in drinking water through ingestion and dermal pathways.

Health risk assessments were conducted on 60 samples collected from ten active wells and ten stations within the drinking water distribution network sections in Fariman, Iran. The Superfund risk assessment model from the US Environmental Protection Agency (EPA) was employed to evaluate health risks. Crystal Ball software was used to perform Monte Carlo simulations and sensitivity analyses to reduce uncertainties and assess the impact of each variable on the risk assessment results.

The hazard quotient (HQ) values for Cr from ingestion pathways exceeded the safety level threshold (HQ > 1) for both adults and children in all sampling sites, while for dermal exposure, the HQ was lower than the safe limit for both populations. The mean cancer risk (CR) values for children and adults via ingestion were 4.58 × 10 -4 and 7.9 × 10 -5 , respectively. However, the CR associated with dermal exposure for both groups was deemed negligible.

The health risk of Cr exposure from drinking water exceeds the acceptable safety level for children and adults. This indicates that drinking water is the primary source of Cr exposure for residents in Fariman. It is essential to implement more control measures and suitable purification systems to reduce Cr levels in the water supply in Fariman.

Microplastics (MPs) exposure can affect humans in various ways, with tap water being one of the potential sources. Microplastics can absorb other pollutants and pose risks to both humans and the environment.

The aim of this study was to investigate the presence of MPs in tap water from the drinking water distribution system of Isfahan, Iran, and to determine the exposure to MPs from drinking tap water.

Samples were collected from different points in the drinking water distribution system of Isfahan, Iran. Samples were prepared for analysis through filtration and chemical digestion. The MPs were counted using a scanning electron microscope (SEM), and the composition of MPs was analyzed using a micro-Raman spectrometer.

The concentration of MPs in tap water was found to be 287.0 ± 65.9 MPs/l. MPs ≤ 10 µm were the predominant sizes, and fibers were the predominant shape. Polyethylene terephthalate, polyethylene, and polypropylene were the most frequently identified MPs, respectively.

Considering that the Iranian population consumes 7 - 15 liters of water daily for drinking and cooking, it is estimated that the average intake of MPs through cooking and drinking water is 2009 - 43,051 particles per day.

Arsenic (As) is a highly toxic and carcinogenic element. Drinking water and some foods (for example, rice, cereals, or fruit juices) are major sources of arsenic. Chronic arsenic poisoning, or arsenicosis, causes internal disorders, such as liver damage, as well as cancers. The purpose of this review study was to examine the epidemiological literature on the side effects of arsenic on liver cancer. Initially, 112 articles from January 1, 2000, to March 1, 2023, were found in the mentioned databases. Then, by removing duplicate items, 85 articles entered the stage of examining the title of the articles and removing irrelevant items based on the title of the article. After reviewing the full text of 38 articles, 14 articles were included in the study and used to investigate the effect of arsenic in drinking water on liver cancer. Many environmental pollutants, including arsenic, can cause many diseases in the human body. This metal can generally enter all body organs through the blood circulation system and affect them. The results of previous studies have shown that long-term exposure to arsenic causes disruption in normal liver function (hepatomegaly, sclerosis, fibrosis, and cirrhosis). Various mechanisms have been introduced for arsenic carcinogenesis. Among the important mechanisms that cause liver carcinogenesis by arsenic, the following can be mentioned: disturbance of the balance of liver enzymes, damage to the DNA wall, its destruction, inability to repair DNA, inappropriate function of estrogens, and liver apoptosis.

High concentrations of nitrate, nitrite, and fluoride in drinking water can cause adverse health effects. This study aims to investigate concentration and health risks assessment of nitrate, nitrite, and fluoride ions in water reservoirs of Mehriz city and Bahadoran district.

Monthly sampling was done from water reservoirs of Mehriz city and Bahadoran district for 6 months. Nitrate, nitrite, and fluoride concentrations were measured in the samples using a spectrophotometer. Then, health risk assessment and sensitivity analysis were performed on the obtained data using Crystal Ball software and Monte Carlo simulation method.

Nitrate, nitrite, and fluoride concentrations were lower than the standard limitation in all of the studied areas. Risk assessment findings indicated that hazard quotient (HQ) values of nitrite in Miankoh-Movahedin, Bidok and Bahadoran water reservoirs were less than 1 for all age groups. HQ values of nitrate were also below 1 for all age groups except children. HQ values of fluoride in Bahadoran water reservoir were below 1 for all age groups except children.

Health risk of consuming water containing nitrates and fluorides is high for children. Based on sensitivity analysis, the concentration of nitrate and fluoride in drinking water is the key factor in raising health risks. Reducing nitrate and fluoride concentrations in drinking water can reduce health risks in the population.

One of the sustainable development goals (SDGs) is universal access to clean water and basic sanitation by 2030. Water, sanitation, and hygiene (WASH) support SDG targets such as eliminating poverty and improving health and education.

The sample of this study amounted to 30 schools consisting of 10 elementary schools, 10 junior high schools, and 10 senior high schools. Sampling was based on stakeholder decisions on several issues related to washing.

This study was conducted by directly observing schools regarding the amount of drinking water, number of toilets, bathrooms, handwashing facilities alone, and handwashing facilities with water and soap. The results showed that elementary and junior high schools have insufficient toilet facilities and low handwashing facilities with water and soap. The average number of handwashing facilities with water and soap in schools in Bekasi City, Indonesia, was 1 for elementary schools, followed by junior high schools and high schools for 4-5 points.

As soap is still unavailable in many Bekasi City schools, and there are inadequate handwashing facilities, it is recommended that handwashing facilities must be available with soap and water.

Water quality and safety are fundamental to human development and well-being. Therefore, the purpose of this study was to determine the bacteriological and mineral content of water in Ho, the capital city of the Volta Region of Ghana.

Sachet, bottled, and tap water were sampled from January to February in 2019 due to the high rate of consumption and their presumed quality which were taken at random from five different locations throughout the municipality. Water quality assessment protocols were utilized to ascertain the bacteriological as well as mineral contents of the samples, whilst ANOVA was used to determine statistical difference and significance at p<0.05.

The maximum Heterotrophic Plate Count for tap water was 9.95±0.64×105 Colony Forming Unit (CFU)/ml, for sachet water was 7.46±0.09×106 CFU/ml, and for bottled water was 1.10±0.56×105 CFU/ml, all obtained on nutrient agar. For MacConkey agar, maximum growth was 2.94±0.03×106, 9.42±1.67×106, and 2.31±0.77×105 CFU/ml for tap, sachet, and bottled water, respectively. The Xylose Lysine Deoxycholate Agar indicated maximum growth of 1.84±0.34×103, 5.72±0.06×106, and 5.50±2.12×104 CFU/ml for tap, sachet, and bottled water, respectively.
The physical parameters such as pH, turbidity, color, and conductivity were within the recommended limits set by the Ghana Standards Authority. However, tap water recorded the highest turbidity, bottled water recorded the highest and least pH and turbidity, respectively. Moreover, the mineral analysis revealed high levels of phosphate (PO₄³⁻), chloride (Cl-), and sodium (Na) in bottled water, and total iron (Fe) was relatively high in several tap and sachet water samples, the latter item also recorded the highest for ammonia (NH3).

Overall, the tap, sachet, and bottled water samples exhibited varied levels of microbial, and mineral contents whilst the physical parameters were relatively within the recommended levels. The sachet and tap water were the least wholesome in comparison with the bottled water samples.

The quality of drinking water includes the microbial, chemical and physical parameters of water, and non-standard values of these parameters cause water pollution. Water improvement has a direct relationship with the reduction of infectious diseases. The aim of this study was to Investigating and determining the critical points Ahvaz drinking water.

This descriptive sectional study was done during 2019 to 2022 (3 years). Tests and monthly reports are based on the methods listed in the method standard were collected directly from distribution network drinking water in Ahvaz drinking water. Statistical analysis, including the one-sample t-test was used to compare the average with the standard level. The significance level was 0.05 used by SPSS version 22 software in all analyses.

result of this study, out of 172 cases, the cause of the crisis is due to broken water pipes, 62 cases are in the west region and 110 cases are in the east region. Based on result, out of 22 cases, the cause of the crisis is due to the lack of sewage overflow in 1 case in the western region and 21 cases in the eastern region. In total, there is a significant difference in the occurrence of crisis causes in the water network between the east and west regions of Ahvaz, and the east region (86.4% of crisis cases) has a higher percentage of crisis causes than the west region of Ahvaz (13.6%). from crisis cases) is included.

In general, the best way to guarantee the quality of drinking water, reduce incidents and record critical cases in the drinking water distribution network is to implement a comprehensive management system with the cooperation of all relevant organizations. The new approach of the World Health Organization (WHO) to achieve this goal is to implement the water safety program.

Heavy metals are one of the most harmful groundwater contaminants due to their toxicity and persistence in the environment. This study aimed to assess the impacts of heavy metals on the quality of groundwater within the M’Zab Valley used for human consumption and irrigation and its potential impact on public health.

In this study, the samples taken from eight phreatic aquifer wells situated along the M’Zab Valley, from upstream to downstream, were analyzed, and chronic daily intake (CDI) of cadmium, hazard quotient (HQ), and target organ risk (TOR) for the kidney were computed for child, infant, and adult age groups.

It was revealed that the superficial aquifer water is of poor quality and frequently exceeds the drinking water standards, particularly for Cd, Cr, and Zn, which poses a health risk for inhabitants. The study found that the CDI values for Cd for each age group (infants, children, and adults) were below the safe limit established by the World Health Organization (WHO), but the data reveals that the concentration of the HQ is considerably greater in infants than in children and adult groups, considering that infants have the highest estimated daily intake of Cd and TOR for the kidney. Thus, infants may be exposed to a greater health risk associated with cadmium exposure.

According to the results of the present study, continuous monitoring of water quality and treatment measures to reduce elevated pollutant levels that harm human health are strongly advised to preserve and safeguard groundwater quality from various forms of pollution.

Toxic Heavy Metals (THMs) threaten food safety and result in human poisonings. It seems to be few studies on THMs contamination in food chain in developing countries. Current investigation determine the concentration and health risk of arsenic (As), cadmium (Cd), lead (Pb), as well as mercury (Hg) in fish and water at Nsukka, Metropolis, Enugu state, Nigeria.

Forty eight samples; 24 (catfish and tilapia) fish and 24 (borehole, sachet, and bottled) water were randomly collected from two major markets and districts in Nsukka Metropolis and were evaluated for THMs using Atomic Absorption Spectrophotometer. The Estimated Daily Intake, Target Hazard Quotient, Hazard Index, and Cancer Risk (CR) were assessed as well.

THMs analaysis showed that As, Cd, and Hg were at 100% and Pb being at 16% in all the fish samples while 12.5% of fish of exceeded the Hg Maximum Permissible Limit (MPL) of 0.050 mg/kg, that not statistically significant (p>0.05).On the other hand, based on the analysis of all water samples, Hg and As were detected at 100% rate, Cd at 58.3% while Pb was not identified. The values above the MPL appeared to be 9 (37.5%), 2 (8.3%), and 3(12.5%) for Hg, As, and Cd, respectively in water while not statistically significant (p>0.05). The mean value of Hg (0.06425 mg/kg) in roasted fish as well as Cd (0.0065 and 0.0105) mg/ml in tap and bottled water respectively surpassed the MPL although not statistically significant (p>0.05). The Estimated Daily Intake of THMs except Cd in fish were proved to be within the Provisional Tolerable Daily Intake in contrast with As and Cd in water. CR is present both in children and adults with CR value >1.

The finding of THMs in fish and water above the MPL is regarded as potential health risk for the consumers of such contaminated water and fish in the investigation scope.

Contamination of water sources with toxins is an environmental problem and a serious threat to the health of societies. This study aimed to ascertain the remaining levels of toxins in urban drinking water networks and compute the water quality index.

To examine the residual concentration of diazinon, chlorpyrifos, and dichlorvos in urban drinking water distribution networks, 35 underground and surface water sources were sampled in Tiran-o-Karvan in Isfahan province, Iran. GC-ECD device was used to analyze the samples.

Diazinon was not observed in any of the sampling seasons. The maximum concentration of chlorpyrifos and dichlorvos was 61 and 100 ppb, respectively. Although chlorpyrifos was seen more in the hot season and dichlorvos in the cold season, the mean concentration of these toxins in different seasons was lower than the guidelines of Iran and the World Health Organization (WHO). The mean concentration of nitrate, and hardness, in wet and dry seasons was 46.23 and 46.42, and 343.7 and 338.8 mg/l, respectively.

The mean and standard deviation of quality index of Iran's water resources (IRWQI) in wet and dry seasons were 52.16 ± 45.3 and 50.69 ± 15.8, respectively. The residual concentration of toxins in some water sources of this city exceeded the guidelines of Iran and the WHO in summer and spring.

The present study was conducted to assess the gastrointestinal health effects and other health effects due to consumption of drinking water, to analyze the water quality parameters (bacteriological and free residual chlorine), and to find out the methods of purification of water at household level and hand washing technique among people in urban Vadodara.

A cross‑sectional study was carried out at urban Vadodara city. 2609 participants were included in the study from among 720 households. 60 households from each selected water tank area were included. Interviews were conducted to know the health effects of water as well as method of purification, hand‑washing technique, and the history of gastrointestinal problems. Thirty‑eight water samples were tested hydrogen sulfide (H2S) strip test and multiple tube method.

4.21% had history of diarrhea in the last 2 weeks. 0.99% had typhoid and 0.65% had history of Jaundice in the past year. H2S Strip test was Negative and no single coliform was found in all 38 water samples. The free chlorine levels in all the tanks were found to be higher than the normal levels. 43.05% participants were using simple cloth or sieve for purification of water followed by 35.97% participants were using reverse osmosis. 14.25% participants were not washing hands before cooking while 5.13% participants were not washing hands after going toilet.

Supplied drinking water was bacteriologically safe. Despite that history of diarrhea, typhoid and jaundice was found in the study area.

Heavy metals (HMs) are one of the most important and dangerous pollutants in water resources. This study aimed to determine the HMs concentrations in city water purifier devices or stations in Rafsanjan, Iran in 2022.

This study was conducted descriptively and on a laboratory scale on the input and output of 16 city water purifier devices stations in Rafsanjan in the summer of 2022. Heavy metals and other metals including arsenic (As), lead (Pb), chromium (Cr), copper (Cu), zinc (Zn), iron (Fe), magnesium (Mg), calcium (Ca), sodium (Na), and potassium (K) were tested by inductively coupled plasma mass spectrophotometry (ICP-MS). Also, t-test statistical analysis was used by SPSS software.

The mean concentrations of HMs in the output of city water purifier devices for As, Pb, Cr, Cu, and Zn were ≤ 1, 2.84 ± 0.71, 8.48 ± 1.51, 2.51 ± 1.55, and 18.58 ± 9.24 µg/L, respectively. The difference between the output of water purifier devices and standard values ​​for As, Cr, and Cu was significant (p ≤ 0.001). Other metals concentrations in the output of water purifier devices for Fe, Mg, Ca, Na, and K were 0.03 ± 0.008, 6.72 ± 0.92, 8.38 ± 1.71, 64.11 ± 2.56, and 2.34 ± 0.08 µg/L, respectively. The HMs removal efficiency of city water purifier devices for As, Cu, and Pb were ≥ 99%, 83.33%, and 56.33%, respectively.

The HMs removal efficiency of city water purifier devices stations in Rafsanjan City was appropriate due to the use of filters containing alumina and iron hydroxide media.