Factors affecting the quality of bottled water

Fluence-based QMRA model for bacterial photorepair and regrowth in drinking water after decentralized UV disinfection

Ultraviolet disinfection is a promising solution for decentralized drinking water systems such as communal water taps. A potential health risk is enzymatic photorepair of pathogens after UV disinfection, which can result in regrowth of pathogens. Even though photorepair is a known issue, no formal risk assessments have been conducted for photorepair after UV disinfection in drinking water. The main objective was to construct a quantitative microbial risk assessment (QMRA) of photorepair after UV disinfection of drinking water in a decentralized system. UV disinfection and photorepair kinetics for E. coli were modelled using reproducible fluence-based determinations. Impacts of water collection patterns, and wavelength-dependent water container material transmittance, sunlight intensity, and photorepair enzyme absorbance were quantified. After UV disinfection by 16 or 40 mJ/cm² of < 5-log microorganisms per L, risk of infection did not exceed 1-in-10,000 under conditions permitting E. coli photorepair. Risk from photorepair was less than 1-in-10,000 for photorepair light exposure < 0.75 h throughout the day for UV fluence 16 mJ/cm² or greater. UV disinfection followed by solar disinfection surpassing photoreactivation during storage reduced risk below 1-in-10,000 for photorepair light exposure > 2.5 h between modelled times of 9 AM - 3 PM. The model can be expanded to other pathogens as UV fluence and photorepair fluence response kinetics become available, and this QMRA can be used to inform the placement of community water access points to reduce risk of photorepair and ensure adequate shelf life of UV disinfected water under safe storage conditions.

Detection of bisphenols in Indian surface water, tap water, and packaged drinking water using dispersive liquid-liquid microextraction: exposure assessment for health risk

The prevalence of bisphenols (BPs) has been well documented in the aquatic environment of many countries, but such studies from India are quite limited. The present work aimed to determine the occurrence of BPs in surface water (n = 96), tap water (n = 172), and packaged drinking water (n = 42) and estimate their exposure to humans. For this, a simple, sensitive, cost-effective, and green analytical chemistry method based on dispersive liquid-liquid microextraction (DLLME) was employed. Bisphenol A (BPA) was found as the most prevalent bisphenol (mean concentration range = 980-6470 ng/L) in all the water samples, with a % detection frequency of 17-39%. Bisphenol S (BPS) and bisphenol Z (BPZ) were also detected in all types of water samples. The mean estimated daily intake (EDI) for total BPs (tap water and packaged drinking water) was found to be 474.37 ng/kg b.w./day in adults and 665.65 ng/kg b.w./day in children, respectively. This indicated that the total exposure to all the detected BPs obtained for adults and children was lower than the temporary tolerable daily intake (t-TDI) recommended by the European Food Safety Authority (EFSA) (4 μg/kg b.w./day), thereby posing no substantial risks to humans from consuming water from the tap and/or packaged drinking water.

Theorizing on neo public assistance: How do race and class impact resource uptake and behavior following disaster?

The consequences of environmental disasters and other ecologic and communal crises are frequently worst in racially/ethnically minoritized and low-income populations relative to other groups. This disproportionality may create or deepen patterns of governmental distrust and stoke health promotion disengagement in these groups. To date, there has been limited contextualization of how historically disenfranchised populations utilize government-administered or facilitated resources following such disasters. Focusing on the water crisis in Flint, Michigan, we examine and theorize on the usage of neo public assistance, free risk reduction resources that are provided to disaster survivors as a liminal means of redressing ills created and/or insufficiently mitigated by the state. We surveyed 331 Flint residents, evaluating their usage of four neo public assistance resources following the FWC, finding low to moderate uptake: 131 residents (39.6%) indicated that they obtained blood lead level (BLL) screenings, 216 (65.3%) had their tap water tested for lead (Pb) and other contaminants, 137 (41.4%) had their home water infrastructure replaced, and 293 (88.5%) had acquired bottled water at community distribution sites. Unemployment, receiving public benefits, and lacking reliable transportation and stable housing were associated with lower uptake of some resources. Compared to White and "Other" race individuals, Black residents were generally more likely to acquire/utilize these resources, suggesting heightened concerns and health promotion proclivities even in the face of observed macro and individual-level challenges. Potential reasons and implications are discussed.

Effect of storage on the levels of phthalates in high-density polyethylene (HDPE) film-packaged drinking water

High-Density Polyethylene (HDPE)-packaged water is a popular choice for urban potable water across Africa. However, the sources and fate of priority chemical contaminants have not been adequately reported. The present study seeks to determine the effect of storage and labelling on the levels of phthalates - dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP) and di(2-hexylethyl) phthalate (DEHP) - in HDPE packaged water. Printed and unprinted 500 mL packet samples, treated water and raw water samples were collected from two major companies in Accra and stored at three temperature levels for 28 days. Phthalates were extracted and pre-concentrated for analysis by GC-MS weekly. The results indicated that phthalates loading became detectable within the first 7 days of incubation, with printed samples showing higher concentrations than unprinted samples at every incubation temperature. The highest concentration was recorded for BBP (1.03 μg/L between a lower and upper confidence limits of 0.62 μg/L and 1.42 μg/L). Temperature significantly affected the concentration of DMP for printed packets (p-value = 0.05) and unprinted samples (p-value = 0.06), BBP across all samples, and DEHP in printed samples (p-value = 0.06). On the other hand, storage duration significantly affected the concentration of BBP across all samples. There was a very strong correlation between printing and the concentration of phthalates in the water samples (p-values <0.001) across the storage temperatures. Effect size analysis established significant differences between site-specific printed and unprinted samples. The present study revealed weak interactions between the selected phthalates and the HDPE matrix, and recommends alternative packaging that can restrict the presence of phthalates and other priority chemicals in plastic packaged drinking water.

Are bottled mineral waters and groundwater for human supply different?

Increasingly, bottled natural mineral water (NMW) is proposed as a healthy and safe alternative to supply water. However, tap supply water often comes from aquifers (TGW), even from the same aquifers as NMW, sharing the exact formation mechanisms and mineralization processes. Therefore, it is hypothesized that NMW and TGW cannot be distinguished. The chemical composition of TGW and NMW samples in Spain has been compared using five criteria: expert judgment, hydrochemistry, legal regulations, statistical analysis, and machine learning (ML). Hydrochemical criteria included all the NMW samples in the TGW group, as did the legal criterion, whereas classical statistical analysis could not find significant differences between the two groups. Although experts could correctly differentiate a small subsample of both types of water with an accuracy of 0.67, ML-based classification with Extreme Gradient Boosting yielded a balanced accuracy of 0.92 on an extremely imbalanced data set. Shapley Additive Explanations (SHAP) analysis identified pH, SiO₂, E, K⁺, Ca²⁺, K⁺/Na⁺ and NO₃^- as the most relevant variables for water type discrimination. The overall consistency and generalization ability of the ML classifier has been proven by the spatial distribution of hits and misses, where the few cases of indistinguishable waters seem to be related to proximity to nature reserves (i.e., land use) more than to geological characteristics. Therefore, it can be concluded that NMW and TGW are indeed different and that only ML could find the hidden structure in the chemical data that determines the differences. This structure originates in how the market and consumers decide which water is ultimately bottled. The results can help on future choices of TGW and NMW in a context of water scarcity.

Water consumption practices in university campuses. The experience of the National Autonomous University of Mexico

The Water Network of the National Autonomous University of Mexico (Red del Agua UNAM) and the Program for the Management, Use, and Reuse of Water in UNAM (PUMAGUA) carried out a survey with the aim of knowing the water consumption practices of the university community in its campuses located in the Metropolitan Area of the Valley of Mexico. A sample of 2,095 students, academics, administrative and support staff participated in this survey. The results show that 74% of the sample consume bottled water and that their average spending is between 0.50 and 1 dollar per day (11 to 20 Mexican pesos). The rates of bottled water consumption contrasts with the perception about water quality, since only 13% consider water quality distributed in the water fountains located within university campuses as 'poor' or 'very poor'. The rates of bottled water consumption among university community are similar to the ones reported by studies in Mexico City and in Mexico as a whole, even though UNAM has a Water Observatory that allows people to know in real time water quantity and quality in university campuses.

Detection of ultrashort-chain and other per- and polyfluoroalkyl substances (PFAS) in U.S. bottled water

Per- and polyfluoroalkyl substances (PFAS) are compounds of emerging concern due to their persistence in the global water cycle and detection in drinking water sources. However, PFAS have been poorly studied in bottled water, especially in the United States. This study investigated the occurrence of PFAS and related factors in 101 uniquely labelled bottled water products for sale in the U.S. Products were screened for 32 target PFAS by solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS). Fifteen of 32 measured analytes were detected, consisting primarily of C3-C10 perfluorocarboxylic acids (PFCA) and C3-C6 and C8 perfluorosulfonic acids (PFSA). PFAS were detected above method detection limits in 39/101 tested products. The Σ₃₂PFAS concentrations detected were 0.17-18.87 ng/L with a median of 0.98 ng/L; 97% of samples were below 5 ng/L. PFCA (83%) and short-chain perfluoroalkyl acids (PFAA) containing 5 or less CF₂ groups (67%) were more prevalent on a mass basis than PFSA and longer-chain PFAA, respectively. Ultrashort-chain PFPrA, measured for the first time in bottled water, accounted for the greatest individual fraction of detected PFAS mass (42%) and was found almost exclusively in products labeled as Spring water. Purified water products contained significantly less PFAS than Spring water products, which was attributed to the use of reverse osmosis (RO) treatment in the majority of Purified waters (25/35) compared to Spring waters (1/45). RO-treated products contained significantly lower Σ₃₂PFAS, long-chain, short-chain, and PFPrA concentrations than products without RO. Although no enforceable PFAS regulations exist for bottled water in the U.S., the finding that some products approach levels of concern justify a framework for monitoring PFAS in bottled water production.

Exploratory analysis of the presence of 14 carbonyl compounds in bottled mineral water in polyethylene terephthalate (PET) containers

Carbonyl compounds (CCs) can migrate from bottles to mineral water because of plastic degradation. An exploratory analysis of the presence a significant number of CCs (14) in bottled mineral water with and without gas in polyethylene terephthalate (PET) containers was performed using ultra-fast liquid chromatography coupled to mass spectrometry (UFLC-MS). The data from the analysis was submitted to chemometric treatment (principal component analysis, PCA). Formaldehyde, acetaldehyde, and benzaldehyde were found in all samples (0.07-125 ng mL^-1). Acrolein and acetone were present in 81% and 75% of the samples, respectively. The concentration of acrolein in carbonated water was up to 3.8 times greater than that measured in non-carbonated water (0.07-0.44 ± 0.01 ng mL^-1). PCA analysis showed that gasification can influence the composition of CCs present in mineral water and that the plastic material of the bottles is a likely source of CCs. In addition, benzaldehyde levels may be associated with the use of recycled materials.

Occurrence, migration and health risk of phthalates in tap water, barreled water and bottled water in Tianjin, China

This study was to investigate the occurrence, migration and health risk of phthalic acid esters (PAEs) in tap water, barreled water and bottled water in Tianjin, China. Six priority controlled PAEs were measured, among which the detection frequency of butyl benzyl phthalate (BBP), dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) was 100%, while the others were not detected. The concentration of DEHP was higher than BBP and DBP in all the samples. The initial ∑₃PAEs concentrations in tap water, barreled water and bottled water were 2.409 ± 0.391 μg/L, 1.495 ± 0.213 μg/L and 1.963 ± 0.160 μg/L, respectively. Boiling tap water could reduce the PAEs content to an extent, but they increased significantly in hot tap water contacting with disposable plastic cups. The migration of PAEs in barreled water and bottled water were positively correlated with storage time and temperature, which could be described by exponential models. The hazard indexes of PAEs in different types of drinking water were very low. However, the human carcinogenic risks of DEHP will reach the maximum acceptable risk level of 10^-6 when bottled water is stored for 8.8 days at 40 °C, 7.7 days at 50 °C, or 6.1 days at 60 °C.

Migration of phthalates from PET water bottle in events of repeated uses and associated risk assessment

Phthalates are widely used as a plasticizer in manufacturing polyethylene terephthalate (PET) bottles to improve softness, flexibility, durability, longevity, and workability. Phthalates are known in instigating profound human health hazards. In many developing countries, lack of proper disposal facilities established for empty PET bottles and the absence of legislation on reuse invariably persuade people to reuse them for storing potable water. An experiment was conducted with two commercial brands of PET bottles to explore the potential of phthalate migration when domestically refilled and reused in multiple times at two temperature conditions. Temperatures of ambient (27 ± 2 °C) and warm (60 ± 2 °C) were selected as the refilling temperatures because of the common practice by people. For both brands, only bis(2-ethylhexyl) phthalate (DEHP) levels were detected in refilled water in every event of reuse. For both brands, mean DEHP levels migrated to water at 60 ± 2 °C were significantly higher (p < 0.05) compared to those at 27 ± 2 °C. Risk analyses carried out on human health suggested that there exist no definite acute or chronic health risks when the refilled water is consumed continuously for 30 years for both temperatures. Still, such risks were higher for the consumption of refilled water of warm temperatures than those of ambient temperature. However, this study elucidates that DEHP migration would be at an alarming rate when the events of reuse of a single bottle increase so that regulations banning the reuse of empty PET bottles are paramount, especially for developing countries.

Degradation of Bacterial Water Quality in Drinking Water after Bottling

Background:

The consumption of bottled water globally, including Iran, has increased tremendously in recent years. This study was designed to assess the bacteriological quality of bottled water and its compliance with the drinking water regulations. In addition, we evaluated bottled waters for the presence of a variety of genera of bacteria and the effect of storage duration on the extent of bacterial contamination.

Methods:

Four hundred samples of bottled water belonging to ten different Iranian brands with various production dates were purchased from supermarkets in Gorgan, Iran, from 2017 to 2018. Bacterial quality of bottled water was assessed using heterotrophic plate count (HPC) followed by usual biochemical tests for identification of bacterial genera, and by the API system.

Results:

The average HPC of bottled water was 9974 colony-forming units per milliliter (CFU/ml). Twelve genera were isolated, among which Bacillus spp. and Escherichia coli were the most and least abundant, respectively. Statistical analysis showed that there was a positive association between water quality and storage duration so that the highest microbial load occurred within the first to third months after bottling. Furthermore, the highest rate of contamination was observed in May when ambient air temperatures commonly reached 40 °C.

Conclusion:

The bacterial quality of bottled water was not according to the standard of drinking water quality. This study demonstrated the variation in bacterial levels after bottling, which indicates the presence of waterborne heterotrophic bacteria, some of which can pose severe health risks to consumers.

A regression-based model to predict chemical migration from packaging to food

Packaging materials can be a source of chemical contaminants in food. Process-based migration models (PMM) predict the chemical fraction transferred from packaging materials to food (F_C) for application in prioritisation tools for human exposure. These models, however, have a relatively limited applicability domain and their predictive performance is typically low. To overcome these limitations, we developed a linear mixed-effects model (LMM) to statistically relate measured F_C to properties of chemicals, food, packaging, and experimental conditions. We found a negative relationship between the molecular weight (MW) and F_C, and a positive relationship with the fat content of the food depending on the octanol-water partitioning coefficient of the migrant. We also showed that large chemicals (MW > 400 g/mol) have a higher migration potential in packaging with low crystallinity compared with high crystallinity. The predictive performance of the LMM for chemicals not included in the database in contact with untested food items but known packaging material was higher (Coefficient of Efficiency (CoE) = 0.21) compared with a recently developed PMM (CoE = -5.24). We conclude that our empirical model is useful to predict chemical migration from packaging to food and prioritise chemicals in the absence of measurements.

Bisphenol analogues in Chinese bottled water: Quantification and potential risk analysis

Polycarbonate (PC) and polyethylene terephthalate (PET) as the package materials have been widely used for Chinese bottled water, from which estrogenic bisphenol analogues might migrate into bottled water. Therefore, there is a strong need to investigate the occurrence and potential risk of such estrogenic bisphenol analogues in Chinese bottled waters. In this study, a GC-MS method was first established and validated for determination of trace-level ten kinds of bisphenol analogues, including bisphenol A (BPA), bisphenol B (BPB), bisphenol C (BPC), bisphenol E (BPE), bisphenol F (BPF), bisphenol P (BPP), bisphenol S (BPS), bisphenol Z (BPZ), bisphenol AP (BPAP), and bisphenol AF (BPAF). BPA was detected in all eleven brands of PET bottled waters with concentrations of 12.4-44.9 ng/L. Some bisphenol analogues were detected in PET bottled waters, and the average concentrations of BPA, BPE, and BPAF in PET bottled waters were found to be 20.8, 1.8, and 2.2 ng/L, respectively. The other eight bisphenol analogues were not detected in PET bottled waters. On the other hand, BPA was detected with high concentrations of 111.8 to 6452.8 ng/L in ten brands of PC bottled water. The average concentrations of BPA, BPS, BPAP, and BPAF were determined to be 1394.3, 1.9, 1.4 and 1.0 ng/L, respectively, while the other seven bisphenol analogues were not detected. High BPA concentration detected in PC bottled waters would remarkably increase human BPA daily intake through daily consumption of such bottled waters. Meanwhile, high estrogen equivalence (EEQ) in PC bottled waters of China is mainly due to the presence of BPA, which may imply adverse effect on human. Therefore, further investigation should be dedicated to assess PC bottled water-associated BPA risks in a more holistic manner.

A comparative study of microbial contamination between public institutional and private residential bottled water dispensers

Bottled water as well as bottled water dispensers is widely used in the United Arab Emirates as a source of drinking water in residential, commercial, and institutional settings. The quality of such waters is of utmost concern as it has the potential to cause waterborne outbreaks, if (re)contaminated. Besides, bottled water dispensers could act as a source of contamination over time, if not cleaned properly on a regular basis. A cross-sectional study was conducted on 40 water samples collected from public and private bottled water dispensers in the emirates of Dubai and Sharjah. Samples were analyzed for heterotrophic plate count bacteria, fecal and total coliforms, and fungal growth. No total and fecal coliforms were detected in any of the samples. Heterotrophic plate counts (HPC) ranged between 0 and 100 CFU/100 ml, with an overall average of 31 CFU/100 ml. There was no significant difference between the HPC bacterial levels of public and private bottled water dispensers. However, a significant association (p < 0.05) was found between fungal growth and the location of the bottled water dispenser within the investigated sites. Survey outcomes also highlighted the need to spread awareness and knowledge amongst general public on basic cleanliness and hygiene practices contributing to safe drinking water and the need for stricter monitoring of public bottled water dispensers cleaning schedules.

Migration and potential risk of trace phthalates in bottled water: A global situation

Increasing attention has been dedicated to trace phthalates in bottled water due to the serious concerns on public health, while there is still a lack of systematic analysis and assessment of current global situation. Through analyzing five representative phthalates in bottled water over 20 countries, this work clearly revealed the phthalates-associated potential risks in both human daily intake and estrogenic effect. In the risk assessment, the kinetic models were also developed to describe and predict phthalates migration. In more than three hundred brands of bottled waters from twenty one countries, the detection frequency of the five targeted phthalates was found to be in the order of dibutyl phthalate (DBP, 67.6%), di-2-(ethyl hexyl) phthalate (DEHP, 61.7%), diethyl phthalate (DEP, 47.1%), benzyl butyl phthalate (BBP, 36.9%), and dimethyl phthalate (DMP, 30.1%). Among the countries studied relating concentrations of DEHP in bottled waters, the top five countries ranked in the order of high to low were Thailand, Croatia, Czech Republic, Saudi Arabia and China with an average level of 61.1, 8.8, 6.3, 6.2 and 6.1 μg/L, respectively. The average levels of BBP, DBP, DMP and DEP in bottled water from Pakistan were high, in which DEP and DMP were ranked 1st among all countries with the average levels of 22.4 and 50.2 μg/L, while BBP and DBP were ranked 2nd and 3rd with the average levels of 7.5 and 17.8 μg/L, respectively. The human daily intake-based risk assessment revealed that phthalates in bottled waters studied would not pose a serious concern on public health. However, the adverse estrogenic effects of phthalates in bottled water from some countries appeared to be significant. This study just shed light on global situation of phthalates in bottled water, and more efforts should be needed to systematically examine the phthalates-related safety of bottled water.

Concentrations of several phthalates contaminants in Egyptian bottled water: Effects of storage conditions and estimate of human exposure

The occurrence and concentrations of six common phthalates were investigated for the first time in bottled water locally produced in the Egyptian market. The compounds investigated were dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), n-butyl benzyl phthalate (BBP), diethyl hexyl phthalate (DEHP), and Di-n-octyl phthalate (D-n-OP). A set of 108 bottled water samples from six different commercial brands of water bottled in transparent polyethylene terephthalate (PET) plastic bottles with high density polyethylene (HDPE) plastic caps were investigated. Water samples were analyzed immediately after purchasing (~2weeks after production), after being stored at room temperature (25±5°C), in a refrigerator (4±1°C) and outdoor under sun exposure (daylight temperature of 40±5°C). Samples were stored up to six months depending on the tested condition. Among the target compounds, only DEHP and DBP were detected in the samples analyzed immediately after purchasing with a detection frequency of 50 and 58% and mean concentrations of 0.104 and 0.082μgl^-1 respectively. Significant positive correlation was obtained between the storage time, temperature and the concentration of phthalate compounds detected in the bottled water, indicating possible migration from the PET plastic material as the source. The estimated contribution of bottled water consumption to the tolerable daily intake (TDI) levels of the two most abundant phthalates observed here for adults and toddlers did not exceed 0.16 and 0.72% for DBP while these values were 0.04 and 0.16% for DEHP respectively. These estimated daily intake values from PET bottled water consumption were far below their respective TDI values and therefore should constitute no adverse health effects.

Limited representation of drinking-water contaminants in pregnancy-birth cohorts

Water contamination and noise have been consistently the least assessed environmental/lifestyle exposures in pregnancy-birth cohorts (PBC). Water quality surveillance data collected during the past decade within urban drinking-water distribution systems call for re-evaluation of water and health issues in the developed world. The objectives of this scientific commentary were to (i) highlight the extent of appraisal of water contamination in exposure assessment studies of PBC, worldwide, and (ii) propose recommendations to increase awareness of emerging water-related risks through their improved representation into PBC study designs in urban centers. Three scientific literature databases (Scopus, PubMed, and Web of Science) were used for a systematic search on worldwide PBC and their publications that considered water contamination and health outcomes. Publicly-available e-databases (ENRIECO, BIRTHCOHORTS, and CHICOS) were also employed for detailed exploration of existing European Union (EU)-based PBC. Out of the 76 PBC identified in the EU territory, only 12 of them incorporated water contamination into their study designs. Among which only 6 PBC published scientific articles that either included data on water contamination and/or water intake estimates. Trihalomethanes but not other disinfection by-products were mostly studied in the PBC around the globe, while fluoride, atrazine, perfluorinated compounds, tetrachloroethylene, and lead were studied to a lesser extent as water contaminants. It appears that chemical-based water contamination and corresponding human exposures represent a largely underappreciated niche of exposure science pertaining to pregnant mother and children's health in PBC. Future PBC studies should grasp this opportunity to substantially reform elements of water contamination in their exposure assessment protocols and effectively combine them with their epidemiological study designs.