RESUMO
Objective To explore the uranium concentration in surface water and drinking water in Beijing, China and the relationship between uranium concentration and gross α activity concentration. Methods Water samples were collected from 16 districts in Beijing. Uranium concentration and gross α activity concentration were measured with WGJ-III trace uranium analyzer and LB6008 six-channel α/β counter using the ultraviolet fluorescence and thick source methods. Results The uranium concentrations in surface water and drinking water were 1.131 and 1.572 μg/L, respectively. The gross α activity concentrations in surface water and drinking water were 0.059 and 0.074 Bq/L, respectively. There were no significant differences in uranium concentration and gross α activity concentration between surface water and drinking water (P > 0.05). The uranium concentration was positively correlated with the gross α activity concentration, with a correlation coefficient of 0.700 (P < 0.05). The gross α activity concentration was determined by the uranium concentration with a determination coefficient of 48%. The committed effective dose of 238U in drinking water was between 3.284 × 10−5 and 1.640 × 10−3 mSv, with an average value of 5.400 × 10−4 mSv. Conclusion The uranium concentration and gross α activity in the surface water and drinking water in Beijing fluctuate and remain in the background range. These values are much lower than the recommended limits of 0.03 mg/L and 0.5 Bq/L stipulated in the GB 5749-2021 Standard for Drinking Water Quality. The annual committed effective dose of 238U through drinking water ingestion is very small.
RESUMO
Objective To investigate the radioactivity levels of total α and total β in drinking water in nine districts of Chongqing City from 2019 to 2021, and to provide reference for the risk monitoring of drinking water in the metropolitan areas of Chongqing. Methods The total α and total β radioactivity levels in water samples were determined by the comparative measurement method and the thin source deposit method in GB/T5750.13-2006 “Standard Examination Methods for Drinking Water-Radiological Parameters”. The monitoring results were assessed according to GB5749-2006 “Standards for Drinking Water Quality” and the fourth edition of the WHO Guidelines for Drinking Water Quality. Results From 2019 to 2021, the total α activity concentration of the water samples measured in the nine districts of metropolitan Chongqing ranged from 0.002 to 0.039 Bq /L, and the total β activity concentration ranged from 0.015 to 0.190 Bq /L. There was no significant difference in the activity concentration (tα=0.545, Pα=0.591; tβ=-1.438, Pβ=0.163>0.05). From 2019 to 2021, the average value of total α radioactivity decreased year by year and its activity value was relatively low, indicating a low health risk. However, the average value of total β radioactivity increased year by year, which should be paid attention to. Conclusion The total α and total β radioactivity in water samples measured in the present study are lower than the standard recommended limits. The estimated annual average effective dose of radiation caused by drinking water is 0.005-0.010 mSv, which is lower than the limit of 0.1 mSv recommended by WHO, and this radioactivity level will not have an impact on the health of residents. However, the total β radioactivity level of the monitoring points in Banan and Shapingba is relatively high compared to other jurisdictions, and further tracking and monitoring should be carried out.
RESUMO
In India, diarrhea prevalence among under 5 years children remains high and is associated with a wide range of bacteria, parasites, and viruses, transmitted through contaminated food and water. The present study aimed at the detection of enteric pathogens in children with diarrhea and its relationship to the source of drinking water. Fecal samples were collected from 157 children from July 2021 to July 2022. Among 157 children, parasitic and bacterial pathogens were detected in 4.5% (7/157). Parasites were detected in 2% (Giardia 67%, H nana in 33%) and bacteria in 2.5% (Ecoli O157 in 75% and salmonella in 25%) cases. Specific sources of drinking water more often associated with diarrhea were hand pumps (43%), house tap water (28.6%), bore well (14.2%), and well (14.2%) cases. Thus, demonstrating the persistence of significant pathogens and re-emphasizing that diarrheal illnesses are preventable through safe drinking water practices.
RESUMO
Introduction: Early introduction of fluids and water affects the duration of breastfeeding, the infant immune system, and possibly causes infants to consume less breast milk, which may, in turn, affect their nutritional and immune status. Objective: This study was carried out to determine water consumption in 0-6-month-old infants and the factors affecting this consumption. Materials and methods: A literature review was conducted in seven electronic databases (Medline, Web of Science, PubMed, ScienceDirect, Scopus, Cochrane Library, and TÜBITAK) for studies published until April 25, 2022, using the keywords: drinking water, infant, and breastfeeding. Results: The systematic review included 13 studies. Five studies were crosssectional, three were descriptive and quasi-experimental, and the others were case-control and cohort studies. It was reported in the examined studies that 86.2% of the infants were around 6 weeks old, 44 % of the infants were 1 month old, 77% were 3 months old, 2.5% were 4 months old, and 2.5 to 85% of the infants were around 6 months old when they first consumed water. The prominent reasons for making the infants drink water are the thought that they need it and cultural reasons. Conclusions: The exclusive breastfeeding of 0-6-month-old infants is the recommendation of reliable health authorities. Nurses play a key role in implementing this practice. In this systematic review, it was seen that families gave their infants water at varying rates in the 0-6-month period, and the factors affecting this situation were revealed. If nurses determine which factors affect families in terms of the early introduction of fluids, they could be able to plan the necessary education and interventions.
Introducción. La introducción temprana de líquidos y agua afecta la duración de la lactancia, el sistema inmune del lactante y posiblemente hace que los lactantes consuman menos leche materna, lo que a su vez puede afectar su estado nutricional e inmunitario. Objetivo. Este estudio se realizó para determinar el consumo de agua en bebés de cero a seis meses y los factores que inciden en este consumo. Materiales y métodos. Se hizo una revisión de la literatura en siete bases de dato electrónicas (Medline, Web of Science, PubMed, ScienceDirect, Scopus, Cochrane Library y TÜBITAK) para estudios publicados hasta el 25 de abril de 2022, utilizando las palabras clave: agua potable, lactante y lactancia. Resultados. La revisión sistemática incluyó 13 estudios. Cinco fueron estudios transversales, tres fueron descriptivos, cuasiexperimentales y los restantes fueron estudios de casos y controles, y de cohortes. En los estudios examinados se informó que le dieron agua al 86,2 % de los lactantes de seis semanas, al 44 % de los lactantes de un mes, al 77 % de los lactantes de tres meses, al 2,5 % de los lactantes de cuatro meses y al 2,5 % a 85 % de los lactantes de seis meses. Las razones principales para dar agua a los bebés son la idea de que los bebés necesitan agua y razones culturales. Conclusiones. La lactancia materna exclusiva es la recomendación de las autoridades sanitarias para los bebés de cero a seis meses. Las enfermeras juegan un papel clave en la implementación de esta práctica. En esta revisión sistemática se observó que las familias daban agua a sus bebés en proporciones variables durante el período de cero a seis meses y se revelaron los factores que inciden en esta situación. Si las enfermeras determinan qué factores afectan a las familias en cuanto a la introducción temprana de líquidos, podrían planificar las medidas educativas y las intervenciones necesarias.
Assuntos
Ingestão de Líquidos , Lactente , Água Potável , Aleitamento Materno , Revisão SistemáticaRESUMO
Abstract This study aimed to explore the association between water, sanitation, and the prevalence of schistosomiasis mansoni in students aged 7 to 17 years from all 27 federative units in Brazil. It was a cross-sectional study conducted based on data on the prevalence of schistosomiasis mansoni referring to 197,567 students from 521 Brazilian municipalities, who participated in the National Survey on the Prevalence of Schistosomiasis Mansoni and Soil-transmitted Helminth Infections (2011-2015). Univariable and multivariable generalized linear models of the negative binomial type were adjusted using 25 and 5% significance levels, respectively, considering municipalities as the unit of analysis. While a protective association was found between access to filtered water in schools and schistosomiasis mansoni prevalence, sanitation in schools was indicated as a risk factor. The collection of wastewater through a network is not universal in Brazil, and even when present, it is not necessarily carried out by the treatment of collected effluents, thus often resulting in the direct discharge of raw sewage into water resources. Regarding septic tanks, only the presence of infrastructure alone does not guarantee its correct use by the population.
Resumo O presente trabalho teve como objetivo explorar a associação entre água, saneamento e a prevalência de esquistossomose mansoni em estudantes de 7 a 17 anos de todas as 27 unidades federativas do Brasil. Tratou-se de um estudo transversal, conduzido com base nos dados de prevalência de esquistossomose mansoni referentes a 197.567 estudantes de 521 municípios brasileiros que participaram do Inquérito Nacional da Prevalência de Esquistossomose Mansoni e Geo-helmintoses (2011-2015). Modelos lineares generalizados do tipo binomial negativo, univariável e multivariável foram construídos considerando níveis de significância de 25% e 5%, respectivamente, e os municípios como unidade de análise. Embora os resultados tenham indicado associação protetora entre o acesso à água filtrada nas escolas e a prevalência de esquistossomose mansoni, o acesso ao saneamento nas escolas foi apontado como um fator de risco. A coleta de águas residuais por rede não é universal no Brasil e, mesmo quando presente, não é necessariamente procedida pelo tratamento dos efluentes coletados, resultando, muitas vezes, no lançamento direto do esgoto bruto em matrizes aquosas. Com relação a soluções individuais como fossa sépticas, a presença da infraestrutura por si só não garante o seu uso correto pela população.
RESUMO
Abstract This study analyzed the relationships between the concentration of natural fluoride in public water supply and meteorological and hydrographic factors in a northeastern region of Brazil. This was a descriptive, analytical, ecological, longitudinal, and field study conducted by collecting water in 23 municipalities (2019 to 2020) of four macroregions of Paraíba (Brazil): coast (1), borborema (2), agreste (3), and outback (4). Four collection sites were selected per municipality: two near and two distant from the water treatment plant. Fluoride concentration was determined using a combined ion-specific electrode and classified according to the Collaborating Center of the Ministry of Health in Oral Health Surveillance. Meteorological, hydrographic, and population characteristics were also collected. All analyzed samples showed natural fluoride; macroregions 2 and 4 showed the highest mean fluoride concentration, macroregion 4 presented the highest mean temperature, and all macroregions showed a similar pattern of precipitation. The mean fluoride concentration of the four macroregions was below the appropriate value to prevent caries. An increase in precipitation would decrease the fluoride concentration in water. In conclusion, the concentration of natural fluoride varied according to meteorological and hydrographic factors. The concentration in surface waters increased during periods of low precipitation. Therefore, this study provided important information to support implementation of community water fluoridation in this region.
RESUMO
Na região Amazônica, cidades como Santarém, no Estado do Pará, Brasil, ainda carecem de Estações de Tratamento de Água para atender toda a população. Nesses locais, medidas domiciliares de desinfecção da água são importantes para preservar a potabilidade e evitar efeitos indesejáveis na saúde. Este estudo avaliou experimentalmente o efeito das medidas domiciliares na eliminação de Escherichia coli em amostras de água. As técnicas avaliadas para esse trabalho foram: (i) hipoclorito de sódio 2,5%; (ii) fervura; (iii) filtro de cerâmica; e (iv) exposição solar. Foram testadas amostras, combinando-se diferentes concentrações de E. coli (entre 3 e 100 unidades formadoras de colônias/100mL). Os resultados mostraram que as medidas domiciliares de desinfecção foram eficazes na eliminação da E. coli, com exceção do filtro de cerâmica, cujas amostras de água, mesmo após a filtragem, apresentaram-se positivas para o crescimento da bactéria. Considerando que a distribuição da água tratada não chega à maior parte da população que reside em Santarém e em áreas periurbanas, como em comunidades quilombolas e ribeirinhas, o uso das medidas como hipoclorito de sódio 2,5%, fervura e exposição solar poderão favorecer a promoção da saúde e diminuir a ocorrência de surtos de doenças diarreicas veiculadas pela água.
In the Amazon region, cities such as Santarém, in the state of Pará, Brazil, still lack Water Treatment Stations to serve the entire population. In these places, household methods of water disinfection are important to preserve potability and avoid undesirable health effects. Our study experimentally evaluated the effect of household methods for eliminating Escherichia coli in water samples. The techniques evaluated for this study were: (i) sodium hypochlorite 2.5%; (ii) boiling; (iii) ceramic filter, and (iv) sun exposure. Samples were tested, combining different concentrations of E. coli (from 3 to 100 colony forming units/100mL). The results showed that household disinfection methods were effective in eliminating E. coli; except for the ceramic filter, the water of which was still positive for their growth, even after filtration. Considering that the distribution of treated water does not reach most of the population living in Santarém and in peri-urban areas, such as the quilombola and riverside communities, the use of such methods as sodium hypochlorite 2.5%, boiling, and sun exposure may favor health promotion and reduce the occurrence of outbreaks of dysentery transmitted by water.
En la región Amazónica, las ciudades como Santarém, en el estado de Pará, Brasil, todavía carecen de Estaciones de Tratamiento de Agua para atender a toda la población. En estos lugares, las medidas de desinfección domiciliaria del agua son importantes para preservar la potabilidad y evitar efectos indeseables en la salud. Este estudio evaluó el efecto de medidas domiciliarias en la eliminación de Escherichia coli en muestras de agua. Las técnicas evaluadas en este trabajo fueron: (i) hipoclorito de sodio al 2,5%; (ii) hervir el agua; (iii) filtro cerámico y (iv) exposición al sol. Se probaron muestras combinando diferentes concentraciones de E. coli (entre 3 y 100 unidades formadoras de colonias/100mL). Los resultados mostraron que las medidas de desinfección domiciliaria fueron efectivas en la eliminación de E. coli, con excepción del filtro cerámico que presentó un resultado positivo para su crecimiento en las muestras de agua, aún después de filtrada. Considerando que la distribución de agua tratada no llega a la mayoría de la población residente en Santarém y en áreas periurbanas como comunidades quilombolas y ribereñas, el uso de técnicas como el hipoclorito de sodio al 2,5%; hervir el agua o exponerla al sol pueden favorecer una promoción de la salud y reducir el surgimiento de brotes de enfermedades diarreicas transmitidas por el agua.
RESUMO
Objective To investigate the gross alpha and gross beta radioactivity levels in drinking water around Shidao Bay Nuclear Power Plant before its operation. Methods Ten sampling sites were set up within 30 km of Shidao Bay Nuclear Power Plant. From 2018 to 2021, samples were collected during the dry season and wet season each year and were tested in a laboratory according to Standard examination methods for drinking water—radiological parameters (GB/T 5750.13—2006). Results From 2018 to 2021, the gross alpha radioactivity in drinking water within 30 km of Shidao Bay Nuclear Power Plant was within the range of about 0.004-0.420 Bq/L, which does not exceed the guided gross alpha radioactivity specified in the National Standard; from 2018 to 2021, the gross beta radioactivity level was about 0.008-1.050 Bq/L. In 2018, the gross beta radioactivity at the sampling site 4.7 km from the Nuclear Power Plant exceeded the guided level specified in the National Standards for Drinking Water Quality (GB 5749—2006), but it fell within the guided level in a repeat laboratory test after deducting the effect of 40K on the gross beta radioactivity. Conclusion After deducting the effect of 40K on the gross beta radioactivity, the gross alpha and gross beta radioactivity levels in drinking water within 30 km of Shidao Bay Nuclear Power Plant are within the guided levels specified in the National Standards.
RESUMO
@#The knowledge and beliefs on the presence of fluoride in drinking water, its purpose and the associated health risks aids in equate water fluoridation and effective prevention programs. Water fluoridation is a safe, effective, and necessary method where adequate doses of fluoride is added into drinking water supplies with the target of assisting in tooth restoration and preventing tooth decay and dental caries. Therefore, this study identifies the level of knowledge and perception of fluoride in drinking water among residents living in Precinct 9, Putrajaya Methods: A cross-sectional, self-administered online questionnaire was used to examine knowledge and perception of fluoride in drinking water of 240 Precinct 9 residents. Descriptive analysis was applied for socio-demographic data and Chi-square was used to compare discrete data. All data obtained were further analyzed using SPSS Version 23.0. Results: The highest frequency (percentage) of residents were 213 (88.8%), aged 18-64 years old, 141 (58.8%) female, 214 (89.2%) with tertiary education background and 125 (51.1%) of them lived in Precinct 9 for more than 10 years. Of all participants, 137 (57.1%) and 83 (34.6%) have poor knowledge and medium perception regarding fluoride in drinking water respectively. There was a significant association between those with higher education level with knowledge (p=0.02) and perception (p=0.005) where they were more likely to know about overall fluoride in drinking water. Conclusion: Most participants had limited knowledge and negative perception of fluoride beyond a general sense it was beneficial. It appears that in moving forward to receive the water fluoridation support will need to attend to the challenge of anti-fluoride sentiment influence.
RESUMO
Objective To establish a method for the determination of 10 organophosphorus flame retardants in drinking water by on-line solid phase extraction coupled with high performance liquid chromatography-tandem mass spectrometry (On-line SPE-UPLC-MS/MS). Methods After adding the internal standard, the water sample was filtered by Millipore filtration, and then concentrated and detected by Online SPE-UPLC-MS/MS. Samples were concentrated by C8 SPE column and separated by C18 column with acetonitrile-water-formic acid as the mobile phases gradient elution，and were detected by multiple reaction monitoring (MRM) acquisition under anion mode. Results The 10 organophosphorus flame retardants all displayed good linear relationships within a certain range of concentrations, with the correlation coefficients being more than 0.990. The method detection limits were 0.60-5.50 ng/L, and the spiked recoveries of low, medium and high concentrations were 64%-106% , 83%-104% and 85%-99%, respectively. Conclusion The method is simple, sensitive, rapid, accurate and reliable, so it is applicable for the determination of 10 organophosphorus flame retardants in drinking water.
RESUMO
ObjectiveTo establish a non-targeted screening method for emerging contaminants in drinking water based on high-resolution mass spectrometry and apply it to actual water samples. MethodsA total of 9 drinking water samples collected from 3 reservoirs in Shanghai were purified and concentrated by HLB solid phase extraction column， then separated and analyzed by liquid chromatography high-resolution mass spectrometer and gas chromatography high⁃resolution mass spectrometer. The acquired data were analyzed by Thermo Tracefinder， Excel and other software combined with mzCloud and NIST databases. The methodology was verified with representative compound standards. Pesticide and perfluorinated compounds were taken as examples to analyze their pollution status. ResultsA non-targeted analysis strategy based on liquid chromatography and gas chromatography tandem high-resolution mass spectrometry was established. The pollution level of 20 kinds of pesticides and 4 kinds of perfluorinated compounds identified in 9 drinking water samples were higher in the Huangpu River than in the Yangtze River estuary. ConclusionThe established non-targeted screening method by high-resolution mass spectrometry can detect potential emerging contaminants in drinking water without relying on the standards， which provides a powerful technical means for water quality monitoring and risk assessment.
RESUMO
ObjectiveTo explore the variation rules and health risks of trihalomethane in regional drinking water， and to provide evidence for the innovative water processing technology and the optimization of drinking water quality. MethodsBased on regional drinking water sanitation monitoring， non-parametric rank sum test was used to analyze the effects of residual trihalomethane production in different periods and with disinfection methods. The United States environmental protection agency （USEPA） classic "four-step" health risk assessment model was used to evaluate the carcinogenic risk and non-carcinogenic risk of trihalomethane through drinking water exposure. ResultsThe yield of trichloromethane in wet season was 6.3 μg·L-1， which was higher than that in dry season. Compared with chlorination pretreatment， ozone pretreatment reduced the content of bromomethane dichloromethane. Compared to liquid chlorine disinfection， sodium hypochlorite treatment incresed the levels of trichloromethane and bromomethane chloride. Although the total carcinogenic and non-carcinogenic risks of trihalomethane in drinking water in the region were at safe levels， they were above the acceptable limits occasionally. The highest carcinogenic risk of trihalomethane were dichlorobromomethane and chlorodibromomethane，and the highest non-carcinogenic risk was trichloromethane. The health risk of children was 1.2 times higher than that for adults. ConclusionThe production of residual trihalomethane in drinking water in this area is relatively low， which is less harmful to the health of adults and children. Monitoring， including other disinfection byproducts， should continue and appropriate disinfection techniques for drinking water should be explored.
RESUMO
Background The concentrations of disinfection by-products (DBPs) are varied by different water sources, disinfectants, or treatment processes in Wuxi, and the associated health risks are also different. Objective To understand the levels of trihalomethanes (THMs) and haloacetamides (HAcAms) in drinking water in Wuxi, and their variations by water sources, seasons, disinfectants or treatment processes, aiming to provide technical support for ensuring the safety of drinking water. Methods In dry period (December 2019) and wet period (July 2020), the finished water and tap water (from the beginning, middle, and end of the drinking water distribution network) from 12 centralized water treatment plants in Wuxi were collected to detect the concentrations of THMs and HAcAms in water samples. A purge and trap-gas chromatography-mass spectrometry method was applied to detect trichloromethane (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and tribromomethane (TBM), and a solid-phase extraction-gas chromatography-mass spectrometry method to detect dichloroacetamide (DCAcAm), trichloroacetamide (TCAcAm), bromochloroacetamide (BCAcAm), dibromoacetamide (DBAcAm), bromodichloroacetamide (BDCAcAm), dibromochloroacetamide (DBCAcAm), and tribromoacetamide (TBAcAm). Analyses and comparisons were made on the concentrations of THMs and HAcAms in drinking water by water sources (the Yangtze River/the Taihu Lake/reservoir), wet/dry seasons, disinfection methods (liquid chlorine/sodium hypochlorite), and treatment processes (conventional treatment/conventional+advanced treatment). Results A total of 96 drinking water samples were collected in Wuxi. THMs were positive in all the water samples (100%), with concentration ranging from 1.027 to 40.225 μg·L−1 and the M (P25, P75) concentration being 24.782 (17.784, 30.932) μg·L−1. None of the 4 THMs exceeded the standard limit of the Standards for drinking water quality (GB 5749-2022 ), and the order of the 4 THMs concentrations from high to low was TCM > BDCM > DBCM > TBM. Five of the 7 HAcAms were detected, the total concentration ranged from 0.137 to 3.288 μg·L−1, and the M (P25, P75) was 0.808 (0.482, 1.704) μg·L−1. The DCAcAm concentration was the highest (2.448 μg·L−1), followed by BCAcAm, while TCAcAm and DBCAcAm were not detected. The M (P25, P75) of the total concentration of THMs in the drinking water from the Taihu Lake was 33.353 (26.649, 36.217) μg·L−1, that of the Yangtze River was 27.448 (24.312, 31.393) μg·L−1, and both were higher than the level of the reservoir [16.359 (2.305, 21.553) μg·L−1] (P<0.05), while the M (P25, P75) of the total concentration of HAcAms in the drinking water from the Taihu Lake was 0.616 (0.363, 0.718) μg·L−1, which was lower than those of the Yangtze River [0.967 (0.355, 2.283) μg·L−1] and the reservoir [1.071 (0.686, 1.828) μg·L−1] (P<0.05). There were no statistically significant differences in the total concentrations of THMs and HAcAms between wet season and dry season, or between different disinfection methods (P>0.05). The M (P25, P75) concentrations of THMs and HAcAms in drinking water after advanced treatment process involving ozone, activated carbon, and membrane were 20.565 (3.316, 27.185) μg·L−1 and 0.623 (0.452, 1.286) μg·L−1 respectively, and were lower than the corresponding values after conventional treatment process, 28.740 (23.431, 35.085) μg·L−1 and 0.934 (0.490, 2.116) μg·L−1 respectively (P＜0.05). Conclusion The concentrations of THMs and HAcAms in drinking water in Wuxi are generally at a low level. The levels of controlled THMs meet the requirements of national standards, and the levels of uncontrolled HAcAms as new DBPs are up to μg·L−1. The concentrations of the two kinds of DBPs in drinking water vary by water sources. The concentrations of THMs and HAcAms produced by the advanced treatment process are lower than that by the conventional treatment process.
RESUMO
@#Abstract: Objective To evaluate the completion and final effect of key parasitic disease prevention and control planning tasks in Hubei Province from 2016 to 2019, summarize the experience, find out the problems, and provide the basis for the next stage of prevention and control. Methods According to the requirements of the Final Evaluation Plan of the National Plan for the Prevention and Control of Hydatid Disease and Other Major Parasitic Diseases (2016-2020), a retrospective survey method was adopted to collect relevant data on the implementation and safeguard measures of the prevention and control of major parasitic diseases, and population infection status in Hubei Province in 2016-2019. Results From 2016 to 2019, We carried out 2 920 992 person times of publicity and education, 209 times of prevention and control technology training, 7 680 person times of business training, with an average of 52 sessions and 1 920 person times per year. We have allocated 3.445 2 million yuan for the prevention and control of parasitic diseases, including 1.722 2 million Yuan froom provincial government, to achieved full coverage of safe drinking water in rural areas under the current national standards, and 7.687 9 million harmless toilets have been built in rural areas. From 2016 to 2019, we carried out 39 658 person times of monitoring and disease investigation, the infection rate of human liver fluke was 0, and the infection rate of soil transmitted nematode was 0.42%. While the annual infection rates varied, there was no statistically significant difference in infection rate between years (χ2＝2.276, P>0.05), but there were statistically significant differences in the infection rates between various soil nematodes (χ2=112.807, P<0.01). From 2016 to 2019, a total of 5 393 people were detected at 17 monitoring points, with the serum positive rate of 3.93% for paragonimiasis, there was a statistically significant difference in serological positive rate between years (χ2=146.011, P<0.01); a total of 738 stream crabs were collected, and the infection rate of intermediate host was 16.26%, wtih a statistically significant difference in the infection rate of stream crabs between years (χ2=49.731, P<0.01). Conclusions From 2016 to 2019, we adhered to the prevention and control strategy of "prevention first, prevention and control combined", implemented comprehensively various prevention and control measures, and achieved remarkable results in Hubei Province. The key parasitic diseases have been in a low epidemic situation, meeting the requirements of the prevention and control objectives. But the transmission risk still exists, the next step is to continue to strengthen security and monitoring and consolidate the achievements of prevention and control.
RESUMO
Objective To understand the sanitary status of drinking water quality in stations along Hexi Corridor Railway from 2018 to 2020. Methods Among of 270 samples of drinking water collected by a railway CDC from 2018 to 2020 were detected and analyzed. Results A total of 270 water samples were detected from 2018 to 2020. Among them, 90 water samples were detected in train water supply stations, and 89 were qualified, with a qualified rate of 98.89%. 180 water samples were detected in non-train water supply stations, and 119 samples were qualified, with a qualified rate of 66.11%. The qualified rate of water quality test items in train water supply stations was significantly higher than that in non-train water supply stations (χ2=36.44, P＜0.05). There was no significant difference in the qualified rate of water quality test items in different years (χ2=2.4,3.01, 0.04, P＞0.05). Conclusion The drinking water source of each station along the Hexi Corridor Railway is supplied by deep groundwater. Without adding disinfectant, the total bacterial count, coliform group, Escherichia coli and other indicators of drinking water in all stations meet GB5749-2006 “sanitary standard for drinking water”. This raises a question on the necessity to add disinfectant when deep groundwater is used as drinking water source. However, the train water supply station, which is used as the source of secondary water supply, provides drinking water for railway train passengers. The free residual chlorine in the water after chlorination can continuously kill microorganisms in the water. Therefore, it is necessary to add disinfectant to the source water of the train water supply station.
RESUMO
Objective To assess the health risks of fluoride in drinking water in rural schools in drinking-water fluorosis areas in Shaanxi Province, and to provide a scientific basis for formulating measures to prevent fluoride and improve water quality. Methods The drinking water of rural schools in Guanzhong and northern Shaanxi Province was monitored from 2017 to 2020. The fluoride concentration was evaluated in accordance with the “Sanitary Standards for Drinking Water” (GB5749-2006). The health risk assessment method recommended by USEPA was used to assess the health risk of rural students exposed to fluoride through drinking water in the two regions. Results A total of 2 826 water samples were monitored from 2017 to 2020. The overall compliance rate of fluoride in water quality was 92.29%, with an average concentration of 0.500 mg/L. The non-carcinogenic health risk of fluoride in drinking water in rural schools in drinking-water fluorosis areas was 0.05). In the same age group, the non-carcinogenic health risk of fluoride in groundwater was higher than that in surface water (P sedimentation filtration > conventional treatment > untreated (P < 0.05). Conclusion The non-carcinogenic risk of oral intake of fluoride in drinking water from rural schools in drinking-water fluorosis areas in Shaanxi Province is still at an acceptable level. In the future, it is necessary to continue to promote comprehensive prevention and treatment measures focusing on water improvement and fluoride reduction.
RESUMO
Background A variety of substances in drinking water are hazardous to human health and there are health risks associated with ingestion of these substances via drinking water. Objective To assess the carcinogenic and non-carcinogenic health risks of drinking water in Shijiazhuang from 2014 to 2021. Methods The collection, preservation, and testing of 10529 drinking water samples (including finished water and tap water) in Shijiazhuang were conducted from 2014 to 2021 and followed the Standard examination methods for drinking water (GB/T 5750—2006). The health risks of 15 chemicals in drinking water by oral exposure were assessed using the US Environmental Protection Agency's four-step method combined with Monte Carlo simulation. Results Among the 15 chemicals in drinking water assessed for their health risks at general exposure levels and high exposure levels via oral route in Shijiazhuang from 2014 to 2021, the leading three chemicals and related values of carcinogenic risks for adults were cadmium (1.11×10−4, 2.98×10−4), arsenic (5.88×10−5, 1.56×10−4), and chromium (5.48×10−5, 2.41×10−4), and the leading three chemicals and related values of non-carcinogenic risks were fluoride (3.57×10−1, 6.57×10−1), arsenic (1.31×10−1, 3.47×10−1), and nitrate (1.14×10−1, 5.98×10−1). The health risk values of trichloromethane and aluminum were elevated but still in acceptable ranges. Drinking water-associated health risk values were higher in males than in females, such as the cancer risk for general exposure levels of arsenic in men was 5.76×10−5, compared to 5.72×10−5 in women. The health risk values of cadmium, chromium, fluoride, nitrate, and other chemicals in ground water were higher than those of surface water, and the health risk values of trichloromethane and carbon tetrachloride were lower than those in surface water, such as the non-carcinogenic risk value for general exposure levels of fluoride in groundwater was 3.61×10−1, compared to 2.27×10−1 in surface water. Factors such as water transmission and distribution links, water period, and season affected the health risks of drinking water. The general exposure levels of trichloromethane in tap water had a higher carcinogenic risk of 1.75×10−7 compared with 8.17×10−8 in finished water. The general levels of arsenic exposure was higher in the dry season at 1.36×10−1, compared with 1.26×10−1 in the wet season. Conclusion Except that the carcinogenic risk of cadmium at general exposure levels in Shijiazhuang exceeds the maximum acceptable range recommended by US Environmental Protection Agency, the health risk values of the remaining 14 chemicals are below the maximum acceptable risk. The carcinogenic risk values of arsenic and chromium and the non-carcinogenic risk values of fluoride, arsenic, and nitrate are relatively high, but do not exceed the maximum acceptable ranges. The emphasis should be on the management of drinking water in highly exposed areas and populations.
RESUMO
Background Dicamba is widely used in agricultural production in China, but it is extremely soluble in water and can be harmful to human health when it enters the body via water drinking. It is necessary to establish an accurate, sensitive, and rapid detection method to determine the residues of dicamba in domestic drinking water. Objective To establish two methods for the determination of dicamba residues in drinking water by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS) respectively. Methods The conditions of the proposed method using HPLC-MS/MS included CAPCELL PAK ST chromatographic column, ammonium formate water solution and methanol as the mobile phase, and isocratic elution. The system was operated under multiple reaction monitoring mode and electrospray negative ionization mode. Trimethylsilylated diazomethane was used as a derivatizing agent for GC-MS/MS, and an external standard curve was used to evaluate the system. The residues of dicamba in seven water samples of tap water or secondary water supply from six regions in Chengdu were detected by the established systems to evaluate their applicability and to understand the status quo of dicamba residues in drinking water. Results For the HPLC-MS/MS, the linear range of dicamba was 1.00-100 μg·L−1, the regression equation was \begin{document}$\hat Y $\end{document}=1250.9X+2681.5, the correlation coefficient was 0.9988, the relative standard deviations were 1.23%-26.3%, the limit of detection was 0.95 μg·L−1, and the spiked recoveries were 91.8%-111%. For the GC-MS/MS, the linear range of dicamba was 0.200-10.0 μg·L−1, the regression equation was \begin{document}$\hat Y $\end{document}=190597X+40911, the correlation coefficient was 0.9993, the relative standard deviations were 0.64%-3.90%, the limit of detection was 0.18 μg·L−1, and the spiked recoveries were 97.3%-105%. No dicamba residue was identified in the seven water samples of tap water or secondary water supply from six regions in Chengdu by the proposed methods. Conclusion The two detection methods established in this study are sensitive and rapid, meet the requirements from the detection of dicamba residues in drinking water, and provide an experimental basis for subsequent research on the detection of dicamba residues. In the future, it is necessary to continue to pay attention to the pollution of dicamba in drinking water in Chengdu.
RESUMO
Background The safety of drinking water is closely related to people's health. In recent years, relevant studies have identified some health related problems with drinking water in Inner Mongolia Autonomous Region. The complex and diverse natural environment embraced by the vast jurisdiction of the region may lead to uneven drinking water quality across the region. Objective To evaluate eight chemicals including arsenic, cadmium, chromium (hexavalent), lead, mercury, fluoride, trichloromethane, and carbon tetrachloride in urban drinking water in Inner Mongolia Autonomous Region in 2021, and to provide reference for optimizing urban water supply system and ideas for further developing strategies to promote population health. Methods A total of 1228 monitoring sites were set up in urban areas of Inner Mongolia, and water samples were collected once in dry season (May) and once in wet season (August−September). Eight chemicals of interest in drinking water were detected according to the Standard examination methods for drinking water, and assessed for health risks using the health risk assessment model recommended by the United States Environmental Protection Agency (USEPA) and following the Technical guide for environmental health risk assessment of chemical exposure. Mann-Whitney U test was used to compare the concentrations of eight chemicals in urban drinking water by water seasons and water sample types. Results In 2021, a total of 2381 samples of urban drinking water were tested in the Inner Mongolia Autonomous Region, including 1195 samples in wet season and 1186 samples in dry season; 389 samples of finished water and 1992 samples of tap water. The positive rates of arsenic and fluoride were 26.25% and 96.77%, respectively. The positive rates of cadmium, chromium (hexavalent), lead, mercury, trichloromethane, and carbon tetrachloride were 6.22%, 16.63%, 6.09%, 16.67%, 18.98%, and 8.36%, respectively. The exceeding standard rate of fluoride was 4.87%. Trichloromethane and carbon tetrachloride were qualified in all samples. There were statistical differences in the concentrations of arsenic, cadmium, chromium (hexavalent), lead, and carbon tetrachloride in urban drinking water between water seasons (Z=−3.847, P<0.05; Z=2.464, P=0.014; Z=−3.129, P=0.002; Z=4.341, P<0.05; Z=4.342, P<0.05). Only fluoride concentration was found statistically different among different water sample types (Z=−2.287, P=0.022). The non-carcinogenic risks of ingestion and dermal exposure to each chemical in drinking water by water seasons and water sample types were all less than 1, but the P95 total non-carcinogenic risks of oral exposure were greater than 1. The P95 carcinogenic risks of oral exposure to some chemicals in drinking water by water seasons and water sample types were>10−4, which suggested carcinogenic risks, while the carcinogenic risks of dermal explore to chemicals were all less than 10−6. Conclusion In 2021, urban drinking water in Inner Mongolia Autonomous Region is generally safe, but arsenic, cadmium, chromium (hexavalent), lead, mercury, and fluoride still exceed the national limits, posing certain health risks.
RESUMO
ObjectiveTo monitor the microbes in urban drinking water in Jiangxi from 2016 to 2020， to analyze the change in microbial qualification rate， and to provide a scientific basis for government decision-making. MethodsAccording to the Standard Examination Method for Drinking Water （GB/T 5750‒2006） and the Standards for Drinking Water Quality （GB 5749‒2006）， the water samples were collected， tested and evaluated for hygienic safety. The chi-square test was used to compare the qualification rates among different water periods， water source types， water supply modes， water samples， treatment processes， and disinfection methods. ResultsA total of 10 584 water samples were collected and examined from 2016 to 2020，with a qualification rate of 97.72%. The qualified rate of the microbiological index increased gradually over the years. There was no statistically significant difference in the microbiological qualification rate of water samples monitored in different water periods （χ2=0.718，P=0.398）， and the qualification rates were 97.85% and 97.60% in dry and abundant water periods respectively. There was a statistically significant difference in the qualification rates of water samples monitored in different water source types （χ2=79.560，P=0.398）， with groundwater having a higher qualification rate of 98.83% than surface water （97.70%）. The microbiological pass rate of water samples differed among different water supply methods （χ2=201.836，P<0.001）. The microbiological pass rates of municipal centralized water supply， self-built centralized water supply and secondary water supply were 97.51%， 88.94% and 96.56% respectively. The microbiological pass rates of water samples differed among different treatment processes. There were differences in the qualification rates of the water samples between different treatment processes（χ2=855.034，P<0.001）， with 98.22%， 67.19%， 95.60% and 53.13% of the conventionally treated， precipitated filtered， disinfected only and untreated water samples， respectively. The differences in the microbiological qualification rates of the monitored water samples between different disinfection methods were statistically significant （χ2=904.993，P<0.001）. Chlorination disinfection， chlorine dioxide disinfection， other disinfection methods and non-disinfected water samples had the pass rates of 98.35%， 98.19%， 84.38% and 60.16%， respectively. ConclusionThe qualified rate of the microbiological index of drinking water in Jiangxi increases year by year， but there are still some drinking water without appropriate disinfectants and water quality treatment processes. There is still a need to strengthen the purification， disinfection and monitoring of drinking water.