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1.
J Hazard Mater ; 421: 126714, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34325293

RESUMEN

Cryptosporidium is a critical waterborne protozoan pathogen found in water resources that have been a major cause of death and serious illnesses worldwide, costing millions of dollars annually for its detection and treatment. Over the past several decades, substantial efforts have been made towards developing techniques for the detection of Cryptosporidium. Early diagnostic techniques were established based on the existing tools in laboratories, such as microscopes. Advancements in fluorescence microscopy, immunological, and molecular techniques have led to the development of several kits for the detection of Cryptosporidium spp. However, these methods have several limitations, such as long processing times, large sample volumes, the requirement for bulky and expensive laboratory tools, and the high cost of reagents. There is an urgent need to improve these existing techniques and develop low-cost, portable and rapid detection tools for applications in the water quality industry. In this review, we compare recent advances in nanotechnology, biosensing and microfluidics that have facilitated the development of sophisticated tools for the detection of Cryptosporidium spp.Finally, we highlight the advantages and disadvantages, of these state-of-the-art detection methods compared to current analytical methodologies and discuss the need for future developments to improve such methods for detecting Cryptosporidium in the water supply chain to enable real-time and on-site monitoring in water resources and remote areas.


Asunto(s)
Criptosporidiosis , Cryptosporidium , Criptosporidiosis/diagnóstico , Cryptosporidium/genética , Humanos , Calidad del Agua , Abastecimiento de Agua
2.
BMJ Glob Health ; 6(10)2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34615660

RESUMEN

OBJECTIVE: The lack of a validated and cross-culturally equivalent scale for measuring individual-level water insecurity has prevented identification of those most vulnerable to it. Therefore, we developed the 12-item Individual Water InSecurity Experiences (IWISE) Scale to comparably measure individual experiences with access, use, and stability (reliability) of water. Here, we examine the reliability, cross-country equivalence, and cross-country and within-country validity of the scale in a cross-sectional sample. METHODS: IWISE items were implemented by the Gallup World Poll among nationally representative samples of 43 970 adults (>15 y) in 31 low-income and middle-income countries (LMICs). Internal consistency was assessed with Cronbach's alpha. Equivalence was tested using multigroup confirmatory factor analysis (MGCFA), the alignment method, and item response theory. Cross-country validity was assessed by regressing mean national IWISE scores on measures of economic, social, and water infrastructure development. Within-country validity was tested with logistic regression models of dissatisfaction with local water quality by IWISE score and regressing individual IWISE scores on per capita household income and difficulty getting by on current income. FINDINGS: Internal consistency was high; Cronbach's alpha was ≥0.89 in all countries. Goodness-of-fit statistics from MGCFA, the proportion of equivalent item thresholds and loadings in the alignment models, and Rasch output indicated equivalence across countries. Validity across countries was also established; country mean IWISE scores were negatively associated with gross domestic product and percentage of the population with access to basic water services, but positively associated with fertility rate. Validity within countries was also demonstrated; individuals' IWISE scores were positively associated with greater odds of dissatisfaction with water quality and negatively associated with lower financial standing. CONCLUSIONS: The IWISE Scale provides an equivalent measure of individual experiences with water access and use across LMICs. It will be useful for establishing and tracking changes in the prevalence of water insecurity and identifying groups who have been 'left behind'.


Asunto(s)
Inseguridad Hídrica , Agua , Adulto , Estudios Transversales , Humanos , Reproducibilidad de los Resultados , Abastecimiento de Agua
3.
Environ Monit Assess ; 193(11): 712, 2021 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-34633550

RESUMEN

Groundwater quality assessment is an important measure to determine the usability of available water based on its physical, chemical, and bacteriological properties. In the present study, 10 physicochemical parameters have been considered for the groundwater quality assessment which include potential of hydrogen (pH), electrical conductivity (EC), total dissolved solids (TDS), sodium (Na+), potassium (K+), total hardness (TH), calcium (Ca2+), magnesium (Mg2+), bicarbonate (HCO3-), and chloride (Cl-). For the analysis, 21 samples for pre- and post-monsoon periods were collected from the wells/bore wells of five designated villages, Chinna Madina, Chittiyyapalem, Typuram, Rajam, and Neelakantapuram of the Butchayyapeta Mandal (sub-district) located in Visakhapatnam District, Andhra Pradesh, for the year 2017. The Bureau of Indian Standards (BIS 2012) has been used in this study to assess the suitability of the water for drinking. The water quality index (WQI) values derived by using WAI were categorized for various levels of water quality ranging from "excellent" to "unsuitable for drinking." To get the spatial distribution pattern, the WQI values of sample points were interpolated in the Arc GIS environment. The results indicated that water quality is good in the north-western parts of the current study area during pre- and post-monsoon seasons.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Contaminantes Químicos del Agua/análisis , Calidad del Agua , Abastecimiento de Agua
4.
J Environ Sci (China) ; 110: 73-83, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34593196

RESUMEN

Significant iron release from cast iron pipes in water distribution systems (WDSs), which usually occurs during the source water switch period, is a great concern of water utilities because of the potential occurrence of "red water" and customer complaints. This study developed a new method which combined in-situ water stagnation experiments with mathematical models and numerical simulations to predict the iron release caused by source water switch. In-situ water stagnation experiments were conducted to determine the total iron accumulation in nine cast iron pipes in-service in Beijing when switching the local water to treated Danjiangkou Reservior water. Results showed that the difference in the concentration increment of total iron in 24 hr (ΔCITI,24), i.e. short-term iron release, caused by source water switch was mainly dependent on the difference in the key quality parameters (pH, hardness, nitrate, Larson Ratio and dissolved oxygen (DO)) between the two source waters. The iron release rate (RFe) after switch, i.e. long-term iron release, was closely related to the pipe properties as well as the DO and total residual chlorine (TRC) concentrations. Mathematical models of ΔCITI,24 and RFe were developed to quantitatively reveal the relationship between iron release and the key quality parameters. The RFe model could successfully combine with EPANET-MSX, a numerical simulator of water quality for WDSs to extend the iron release modeling from pipe level to network level. The new method is applicable to predicting iron release during source water switch, thus facilitating water utilities to take preventive actions to avoid "red water".


Asunto(s)
Agua Potable , Hierro , Cloro , Corrosión , Calidad del Agua , Abastecimiento de Agua
5.
J Environ Sci (China) ; 110: 92-98, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34593198

RESUMEN

Many problems in drinking water distribution systems (DWDSs) are caused by microbe, such as biofilm formation, biocorrosion and opportunistic pathogens growth. More iron release from corrosion scales may induce red water. Biofilm played great roles on the corrosion. The iron-oxidizing bacteria (IOB) promoted corrosion. However, when iron-reducing bacteria (IRB) and nitrate-reducing bacteria (NRB) became the main bacteria in biofilm, they could induce iron redox cycling in corrosion process. This process enhanced the precipitation of iron oxides and formation of more Fe3O4 in corrosion scales, which inhibited corrosion effectively. Therefore, the IRB and NRB in the biofilm can reduce iron release and red water occurrence. Moreover, there are many opportunistic pathogens in biofilm of DWDSs. The opportunistic pathogens growth in DWDSs related to the bacterial community changes due to the effects of micropollutants. Micropollutants increased the number of bacteria with antibiotic resistance genes (ARGs). Furthermore, extracellular polymeric substances (EPS) production was increased by the antibiotic resistant bacteria, leading to greater bacterial aggregation and adsorption, increasing the chlorine-resistance capability, which was responsible for the enhancement of the particle-associated opportunistic pathogens in DWDSs. Moreover, O3-biological activated carbon filtration-UV-Cl2 treatment could be used to control the iron release, red water occurrence and opportunistic pathogens growth in DWDSs.


Asunto(s)
Agua Potable , Biopelículas , Cloro , Corrosión , Microbiología del Agua , Abastecimiento de Agua
6.
J Environ Manage ; 299: 113660, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34481371

RESUMEN

A clear quantification and spatial mapping between supply and demand of water provision service in relation to climate change and urban expansion can provide some guidance to water resources management. Nevertheless, so far, most researches ignored the dynamic changes and influences of supply-demand coupling correlations. In this study, water yield and water demand were quantified and mapped in the Xiangjiang River Basin (XRB) from 2000 to 2018 by using the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) and water-demand models, then the spatial distribution characteristics and their matching relationship were identified by using the univariate local autocorrelation analysis and the common logarithm of water supply-demand ratio (WSDR). With that, the contributions of climate and socio-economic factors to the above-mentioned changes were explored by using geographic detector. Results showed that the annual water yield increased by 20.20% in 2000-2015 and decreased by 33.92% in 2015-2018 affected by precipitation and land use changes; Changsha-Zhuzhou- Xiangtan urban agglomeration (CZX) and Southwest of Yongzhou were the high value areas of water yield (>338 m3/hm2). Due to the urban expansion, the water demand increased by 40.50% from 2000 to 2005 and decreased by 36.39% after 2005; From 2000 to 2018, high value areas of water demand (>53566 m3/hm2) mainly appeared in midstream and downstream with high urbanization level, dense population and developed industry. Under the joint action of precipitation (prep) and urban expansion, the overall state of supply and demand in the upper reaches was surplus, and more than 90% of the regions in midstream and downstream were at the middle and high level of supply shortage, especially in Hengyang and Chenzhou. Consequently, the increasing needs of human beings should be emphasized from the overall perspective of the basin, the growth rate of construction land and the necessary green infrastructure should be controlled reasonably and configured for achieving win-win goals of coordinating environmental protection and urban development.


Asunto(s)
Ecosistema , Agua , China , Conservación de los Recursos Naturales , Humanos , Ríos , Urbanización , Abastecimiento de Agua
7.
J Environ Manage ; 299: 113667, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34482108

RESUMEN

Rain and floods events are responsible for the transport of microplastics in freshwater ecosystems, yet to date, rare study has examined microplastics pollution in urban water supply reservoirs during such events. In this study, we investigated the concentrations and characteristics of microplastic in water and economic fish species with different feeding guilds in the Dafangying Reservoir, an important source of drinking water for Hefei city. Microplastic concentrations in water were relatively higher than that in natural lakes, indicating abundant microplastic contaminants input through overland runoff triggered by flooding. Our results detected five types (fiber, debris, film, microbead and particle) and six colors (black, transparent, blue, yellow, red and green) of microplastics in water samples. Fiber accounted for the dominant shape, which may result from the household sewage from washing clothes and desquamated fiber transported by wind and overland runoff. Meanwhile, transparent was the predominant microplastic color, which can be ascribe to the widely use of intentionally manufactured transparent disposable plastic commodities in cities. Then in fish samples, the microplastic concentrations ranged from 8.75 to 51.3 items/individual in fish guts, and 9.5-52.6 items/individual in fish gills. Our results demonstrated significant higher microplastic concentrations in planktivorous and herbivorous species. The filter feeding capture mode, i.e., engulfing floating prey through frequently drawing in large volume of water confused with microplastics, may result in the higher microplastic concentrations of planktivorous fishes. Due to the dense microplastics adhering on plant surface, herbivorous fishes can concentrate higher microplastics abundance through the ingestion of macrophytes. According to the biological concentration factor (BCF), all the determined microplastics gave BCF far below 1, suggesting the low bioaccumulation capacity of microplastics in fish species.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Animales , Ecosistema , Monitoreo del Ambiente , Peces , Inundaciones , Plásticos , Agua , Contaminantes Químicos del Agua/análisis , Abastecimiento de Agua
8.
J Environ Manage ; 299: 113683, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34526284

RESUMEN

Egypt suffers from severe water scarcity, which affects the sustainability of agricultural production. Therefore, the sustainable use of available water resources under water scarcity requires the adoption of water allocation policies favoring conservative and efficient use. Water management with free satellite data and geographical information system modeling capabilities can be a valuable approach for optimizing the benefits from the available water resources to meet the requirements for agricultural lands. This study aims to (i) detect and evaluate changes in agricultural areas because of urbanization and reclamation activities using Landsat data in 1999, 2009, and 2019 and (ii) update the irrigation water demand by monitoring the seasonal changes of agricultural area based on normalized difference vegetation index. Water management of Fayoum Governorate in Egypt is characterized by a non-uniform distribution flow over its canals; thus, two pilot areas are selected. The first site is the Sinnuris canal, the served areas of which represents the urbanization problem. The other site is the Gharaq canal, the served areas of which represents the urbanization and agricultural expansion situations. The results reveal that changes in agricultural areas considerably affect the uniformity of water management. Urbanization activities reduce the agricultural area by ∼5.0% and 5.7% in Sinnuris and Gharaq served areas, respectively. However, the newly cultivated lands in Gharaq preserve an increase of 5.8% in the total agricultural area. The considerably changed water allocation strategies in these districts since Sinnuris has an excess of 1.5 m3/s of water supply, while the Gharaq area faced an irrigation shortage of 0.26 m3/s in 2019. As per the proposed approach, the decision-makers can readjust the water allocation plan to satisfy the water requirements for other demand areas.


Asunto(s)
Sistemas de Información Geográfica , Tecnología de Sensores Remotos , Agricultura , Egipto , Monitoreo del Ambiente , Urbanización , Inseguridad Hídrica , Abastecimiento de Agua
9.
Huan Jing Ke Xue ; 42(10): 4753-4760, 2021 Oct 08.
Artículo en Chino | MEDLINE | ID: mdl-34581117

RESUMEN

This study quantified an integron gene intI1 and 19 antibiotic resistance genes(ARGs) to identify the ARGs pollution characteristics in 11 drinking water reservoirs of central China. The results indicated that the ARGs abundance did not change significantly over time in the studied reservoir waterbodies. Tetracycline, sulfonamide, and ß-lactam ARGs were dominant. The high abundance and detection rate of two sulfonamide ARGs(sul1 and sul2) suggested that they were the predominant ARGs. No polymyxin resistance genes(mcr-1) were detected, which indicated that the antibiotic restriction policy of China has achieved positive outcomes. Compared with that in other environmental media, the ARGs abundance in the reservoir environment was low. The correlation analysis showed relevance between the water quality indicators and the ARGs, which suggested that the water quality indexes can be used as ARGs pollution indicators in the reservoir environment. The abundance and detection rate of carbapenem ARGs were low owing to their dosage restriction and high degradability. Tetracycline ARGs were closely related to the other resistance gene types, which might have been due to horizontal gene transfer. Although the overall correlation between intI1 and ARGs was modest, it might be the main reason for the spread of several individual ARGs in the reservoir environment.


Asunto(s)
Antibacterianos , Genes Bacterianos , Antibacterianos/análisis , China , Farmacorresistencia Microbiana/genética , Monitoreo del Ambiente , Análisis Factorial , Genes Bacterianos/genética , Estaciones del Año , Abastecimiento de Agua
10.
Environ Sci Technol ; 55(18): 12471-12482, 2021 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-34498866

RESUMEN

Delivering safe water in cities of lower- and middle-income countries remains elusive even where there is a piped supply. Passive, in-line chlorination upstream of the point of water collection reduces child diarrhea without the behavior change required for point-of-use water treatment products or manual chlorine dispensers. We conducted a price experiment to measure effective demand (willingness and ability to pay) for an in-line chlorination service using tablet chlorinators among 196 landlords of rental housing properties in Dhaka, Bangladesh. We offered a 12-month subscription using Becker-DeGroot-Marschak auctions with real money payments. The service consistently delivered chlorinated water and satisfied tenants. Landlords' effective demand for in-line chlorination was similar to or greater than that for point-of-use treatment products and manual chlorine dispensers previously documented among Dhaka households. Over the service period, landlords renting to low-income households had lower effective demand than those renting to middle-income households despite similar initial rates of payment across both groups. Making in-line chlorination financially viable for the lowest-income consumers would likely require service cost reductions, subsidies, or both. Our findings suggest that even revealed preference experiments may overestimate the effective demand needed to sustain water supply improvements, especially in low-income populations, if they only measure demand once.


Asunto(s)
Halogenación , Purificación del Agua , Bangladesh , Niño , Vivienda , Humanos , Abastecimiento de Agua
11.
Nat Commun ; 12(1): 5413, 2021 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-34526495

RESUMEN

Numerous studies have focused on the need to expand production of 'blue foods', defined as aquatic foods captured or cultivated in marine and freshwater systems, to meet rising population- and income-driven demand. Here we analyze the roles of economic, demographic, and geographic factors and preferences in shaping blue food demand, using secondary data from FAO and The World Bank, parameters from published models, and case studies at national to sub-national scales. Our results show a weak cross-sectional relationship between per capita income and consumption globally when using an aggregate fish metric. Disaggregation by fish species group reveals distinct geographic patterns; for example, high consumption of freshwater fish in China and pelagic fish in Ghana and Peru where these fish are widely available, affordable, and traditionally eaten. We project a near doubling of global fish demand by mid-century assuming continued growth in aquaculture production and constant real prices for fish. Our study concludes that nutritional and environmental consequences of rising demand will depend on substitution among fish groups and other animal source foods in national diets.


Asunto(s)
Peces/crecimiento & desarrollo , Abastecimiento de Alimentos/estadística & datos numéricos , Alimentos , Renta/estadística & datos numéricos , Alimentos Marinos/estadística & datos numéricos , África , Animales , Acuicultura/métodos , Asia , Europa (Continente) , Abastecimiento de Alimentos/métodos , Agua Dulce , Geografía , Salud Global , Humanos , Modelos Teóricos , América del Norte , Alimentos Marinos/provisión & distribución , América del Sur
12.
Sensors (Basel) ; 21(18)2021 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-34577487

RESUMEN

Clay-gravel mixture has been widely used in high embankment dams and understanding its seepage characteristics is critical to dam safety. From the instrumental perspective, the realization of continuous pressurized water supply becomes a key technical challenge, significantly restricting the working conditions replicated in previous seepage apparatuses. To this end, a novel water provision system, relying on parallel-disposed sensor-based pressure devices, was introduced, so that the application of an existing large-scale stress-controlled apparatus can be expanded to long-term seepage tests regarding coarse-grained cohesive soils. Constant-head permeability tests were conducted on original-graded clay-gravel mixtures to investigate their hydraulic properties, incorporating the influence of stress relaxation. Test results show that with 35% gravel content, the clay-gravel mixture is suitable for dam construction as the core material. The stress relaxation holds a marginal effect on the hydraulic conductivity of soil. The functionality of this improved apparatus is verified, especially under long-term seepage conditions.


Asunto(s)
Suelo , Movimientos del Agua , Arcilla , Agua/análisis , Abastecimiento de Agua
13.
Artículo en Inglés | MEDLINE | ID: mdl-34574575

RESUMEN

Safe water and sanitation, which give rise to appropriate hygiene, are fundamental determinants of individual and social health and well-being. Thereby, assessing and widening access to sustainable, durable water and sanitation infrastructure remains a global health issue. Rural areas are already at a disadvantage. Poor access to water, sanitation, and hygiene (WASH) can have a major negative effect on students in rural schools. Thus, the paper aims to assess the current condition and the challenge to access WASH in rural Kazakh schools. The study was conducted in three rural schools in Central Kazakhstan. Data were gathered through a survey among pupils, observations of the WASH infrastructure and maintenance, and a face-to-face interview with school administrators. The mean survey response rate was 65% across schools. Results indicated there was no alternative drinking-water source in schools, and 15% of students said they had access to water only occasionally. Half of the students reported that the water was unsafe to drink because of a poor odor, taste, or color. The toilet in school 3 was locked with a key, and a quarter of the students reported there was no access to a key. Moreover, not having gender-separated toilet facilities was a challenge because of the traditional gender norms. Despite the effective regulations and measures of handwashing taken during COVID-19, 27.7% of the students answered that soap was not offered daily in classrooms. Additionally, warm water was only provided in school 2. About 75% of students did not have access to drying materials continuously. The study shows that having the schools' infrastructure is not enough when characteristics, such as availability, accessibility, maintenance, operation, quality of services, education, and practices, are ignored. Cooperation between local education authorities, school administration, and parents should be encouraged to the achievement of the sustainable development goals (SDGs) by 2030.


Asunto(s)
COVID-19 , Agua Potable , Países en Desarrollo , Humanos , Higiene , Kazajstán , SARS-CoV-2 , Saneamiento , Instituciones Académicas , Abastecimiento de Agua
14.
Water Sci Technol ; 84(5): 1125-1135, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34534110

RESUMEN

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.


Asunto(s)
Agua Potable , Universidades , Ingestión de Líquidos , Humanos , México , Calidad del Agua , Abastecimiento de Agua
15.
J Environ Manage ; 300: 113731, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34560462

RESUMEN

Farmers' investment in more efficient irrigation systems represents a primary adaptation strategy when confronting climate change. However, the regional benefits of these investments and their influence on the conflicting demands among different water dependent stakeholders for intensely irrigated regions remains an open question. Using the Pacific Northwest of the United States as an illustrative region of focus, we show that higher irrigation efficiency has diverse effects across stakeholders that are contingent on many local climatic, institutional and infrastructural factors such as the availability of water storage, the location of hydropower generators, and water rights. These complexities limit simple abstractions of irrigation efficiency as broader policy challenge and are central to its inclusion within the class of "wicked problems". Additionally, we argue that the widely used rebound effect concept, which implicitly discourages irrigation efficiency supporting policies, should not be assumed to fully capture the nuances of the complex suite of regional impacts that emerge from irrigation efficiency investments. Consequently, the evaluation of irrigation efficiency investments requires a broader framing across a diversity of perspectives. policies and actions that are pluralistic, context-specific, and closely engage various groups of stakeholders in the policymaking process.


Asunto(s)
Riego Agrícola , Cambio Climático , Agricultores , Humanos , Estados Unidos , Agua , Abastecimiento de Agua
16.
Environ Sci Technol ; 55(19): 12791-12800, 2021 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-34520184

RESUMEN

This work evaluates efficacies of plausible ballast water management strategies and standards by integrating a global species spread risk assessment with a policy cost-effectiveness analysis. Specifically, we consider species spread risks and costs of port- and vessel-based strategies under both current organism concentration standards and stricter standards proposed by California. For each scenario, we estimate species spread risks and patterns using a higher-order analysis of a global ship-borne species spread model and estimate fleet costs for vessel- and barge-based ballast water treatment systems for each standard. We find that stricter standards may reduce species spread risk by a factor of 17 globally and would greatly simplify the complex network of ship-borne species spread. The current policy of IMO standards is most cost-effectively achieved through ship-based treatment, and that any additional risk reduction will be most cost-effectively achieved by port-based (or barge-based) technologies, particularly if these are strategically implemented at the top ports within the largest clusters. Barge-based ballast water management would require a shift in governance, and we suggest that this next level of policymaking could be feasible for special areas designated by the IMO, by State or multistate authorities, or by voluntary port applications.


Asunto(s)
Especies Introducidas , Purificación del Agua , Navíos , Agua , Abastecimiento de Agua
17.
Environ Sci Technol ; 55(19): 12902-12913, 2021 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-34520188

RESUMEN

The drainage of rice soils increases Cd solubility and results in high Cd concentrations in rice grains. However, plant Cd uptake is limited by sorption to iron plaques, and Cd redistribution in the plant is regulated by the nodes. To better understand the interplay of Cd uptake and redistribution in rice under drained and flooded conditions, we determined stable Cd isotope ratios and the expression of genes coding transporters that can transport Cd into the plant cells in a pot experiment. In soil, both water management practices showed similar patterns of isotope variation: the soil solution was enriched in heavy isotopes, and the root Fe plaque was enriched in light isotopes. In rice, the leaves were heavier (Δ114/110Cdleaf-shoot = 0.17 to 0.96‰) and the nodes were moderately lighter (Δ114/110Cdnode-shoot = -0.26 to 0.00‰) relative to the shoots under flooded conditions, indicating preferential retention of light isotopes in nodes and export of heavy isotopes toward leaves. This is generally reversed under drained conditions (Δ114/110Cdleaf-shoot = -0.25 to -0.04‰, Δ114/110Cdnode-shoot = 0.10 to 0.19‰). The drained treatment resulted in significantly higher expression of OsHMA2 and OsLCT1 (phloem loading) but lower expression of OsHMA3 (vacuolar sequestration) in nodes and flag leaves relative to the flooded treatment. It appeared that OsHMA2 and OsLCT1 might preferentially transport isotopically heavier Cd, and the excess Cd was purposefully retranslocated via the phloem under drained conditions when the vacuoles could not retain more Cd. Cd in seeds was isotopically heavier than that in stems under both water management practices, indicating that heavy isotopes were preferentially transferred toward seeds via the phloem, leaving light isotopes retained in stems. These findings demonstrate that the Fe plaque preferentially adsorbs and occludes light Cd isotopes on the root surface, and distinct water management practices alter the gene expression of key transporters in the nodes, which corresponds to a change in isotope fractionation between shoots and nodes/leaves.


Asunto(s)
Oryza , Contaminantes del Suelo , Cadmio/análisis , Isótopos , Hojas de la Planta/química , Raíces de Plantas/química , Suelo , Contaminantes del Suelo/análisis , Agua , Abastecimiento de Agua
18.
BMC Cancer ; 21(1): 1034, 2021 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-34530751

RESUMEN

BACKGROUND: Despite research efforts, the causative factors that contribute to esophageal squamous cell carcinoma (ESCC) in high-risk areas have not yet been understood. In this study, we, therefore, aimed to describe the risk factors associated with ESCC and its precursor lesions. METHODS: We performed an endoscopic examination of 44,857 individuals aged 40-69 years from five high incidence regions of China in 2017-2018. Participants were classified as 4 groups of normal control, esophagitis, low-grade intraepithelial neoplasia (LGIN) and high-grade intraepithelial neoplasia/esophageal squamous cell carcinoma (HGIN/ESCC) using an unconditional logistic regression determine risk factors. RESULTS: We identified 4890 esophagitis, 1874 LGIN and 437 HGIN/ESCC cases. Crude odds ratios (ORs) and adjusted odds ratios were calculated using unconditional logistic regression. Drinking well and surface water, salty diet, and positive family history of cancer were the common risk factors for esophagitis, LGIN and HGIN/ESCC. History of chronic hepatitis/cirrhosis was the greatest risk factor of esophagitis (adjusted OR 2.96, 95%CI 2.52-3.47) and HGIN/ESCC (adjusted OR 1.91, 95%CI 1.03-3.22). Pesticide exposure (adjusted OR 1.20, 95%CI 1.05-1.37) was essential risk factor of LGIN. CONCLUSIONS: Among individuals aged 40-69 years in high incidence regions of upper gastrointestinal cancer, the results provided important epidemiological evidence for the prevention of different precancerous lesions of ESCC.


Asunto(s)
Carcinoma in Situ/etiología , Neoplasias Esofágicas/etiología , Carcinoma de Células Escamosas de Esófago/etiología , Lesiones Precancerosas/etiología , Adulto , Anciano , Consumo de Bebidas Alcohólicas/efectos adversos , Carcinoma in Situ/epidemiología , Carcinoma in Situ/patología , China/epidemiología , Estudios Transversales , Dieta/efectos adversos , Agua Potable/efectos adversos , Neoplasias Esofágicas/patología , Carcinoma de Células Escamosas de Esófago/patología , Esofagitis/diagnóstico , Esofagitis/epidemiología , Esofagoscopía/estadística & datos numéricos , Familia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Plaguicidas/toxicidad , Lesiones Precancerosas/patología , Análisis de Regresión , Factores de Riesgo , Cloruro de Sodio Dietético/efectos adversos , Abastecimiento de Agua
19.
Environ Monit Assess ; 193(10): 629, 2021 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-34490509

RESUMEN

Continuous vigilance of water quality is essential throughout water supply and storage systems to ensure safe water quality and safeguard consumer health. In the present study, sixty-three sampling locations in Sharjah, UAE, were assessed for possible water quality variations from water supply through utilized water storage tanks in buildings. All investigated physico-chemical parameters were within national water quality guidelines except for free residual chlorine (< 0.2 mg/L in 30% of samples), mainly in storage tanks. Compliance of metal concentrations varied with metal type, sampling locations, and points. Highest compliance was reported for manganese, copper, nickel, chromium, and least for iron, lead, and cadmium. No major variations in physico-chemical water quality could be statistically observed using analysis of variance when tracing the water from lower tanks to upper tanks, yet significant variations for turbidity (p = 0.006) were observed from mains to lower tanks and for water temperature (p = 0.026), residual chlorine (p = 0.001), turbidity (p = 0.048), chromium (p = 0.019), copper (p = 0.002), manganese (p = 0.012), and zinc and lead (p = 0.000) from mains to upper tanks. As for investigated microbiological parameters, all investigated samples were completely free from total and fecal coliforms and Pseudomonas aeruginosa. Exhibited ranges of yeasts and molds (0-28 CFU/100 mL) and heterotrophic plate counts (0-356 CFU/mL), though non-enforceable parameters, were always lower than recommended water quality guidelines. Furthermore, Pearson correlation tests exhibited significant correlations for water temperature versus yeasts and molds and electrical conductivity versus sodium and potassium. Statistically (using t-tests), mean heterotrophic plate counts were slightly higher in lower tanks compared to other sampling points. Additionally, mean heterotrophic plate counts were significantly higher in larger tanks exceeding 2000 gallons, in square/rectangular shaped tanks, in tanks exceeding 10 years of age, and in concrete tanks with higher water temperatures. Re-chlorination, proper cleaning, as well as maintenance or upgrade of water storage tanks remain advisable to ensure safe water at point of use.


Asunto(s)
Microbiología del Agua , Calidad del Agua , Monitoreo del Ambiente , Emiratos Árabes Unidos , Abastecimiento de Agua
20.
Cien Saude Colet ; 26(suppl 2): 3647-3655, 2021.
Artículo en Portugués | MEDLINE | ID: mdl-34468659

RESUMEN

Fluoridation is considered an effective and wide-ranging measure in combatting dental caries. Despite being mandatory in Brazil since 1974, the implementation continues to be unequal throughout the country. The objective was to describe and analyze fluorine levels in the waters of the public supply grid of the 2nd macro region of the state of Pernambuco in municipalities with 50,000 inhabitants or more. This is a descriptive study based on a comparison of data from Pernambuco Sanitation Company (Compesa), the Vigifluor Project, the Water Quality Surveillance Information System for Human Consumption (Sisagua) the Brazilian Institute of Geography and Statistics (IBGE) and the National Sanitation Information System (SNIS), on the fluoridation of water in municipalities of the 2nd health macro region of Pernambuco. Although the municipalities studied do not have artificial fluoridation, significant levels of natural fluorine were found in the sources that supply the regions. However, these levels of fluorine do not remain constant in the waters of the supply network of the municipalities studied, therefore there is no effective prevention against caries. Artificial fluoridation is an effective measure in preventing caries and should therefore be expanded in regions that are not yet fluoridated.


Asunto(s)
Caries Dental , Fluoruros , Brasil , Ciudades , Caries Dental/epidemiología , Caries Dental/prevención & control , Fluoruración , Fluoruros/análisis , Humanos , Abastecimiento de Agua
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