scholarly journals Meta-Analysis Enables Prediction of the Maximum Permissible Arsenic Concentration in Asian Paddy Soil

2021 ◽  
Vol 9 ◽  
Author(s):  
Jajati Mandal ◽  
Sudip Sengupta ◽  
Soumyajit Sarkar ◽  
Abhijit Mukherjee ◽  
Michael D. Wood ◽  
...  
Keyword(s):  
Drinking Water ◽  
Decision Tree ◽  
Paddy Soil ◽  
Irrigation Water ◽  
Meta Analysis ◽  
Rice Grain ◽  
Rice Grains ◽  
Guideline Value ◽  
Guideline Values ◽  
The Relationship

It is now well-established that not just drinking water, but irrigation water contaminated with arsenic (As) is an important source of human As exposure through water-soil-rice transfer. While drinking water As has a permissible, or guideline value, quantification of guideline values for soil and irrigation water is limited. Using published data from 26 field studies (not pot-based experiments) from Asia, each of which reported irrigation water, soil and rice grain As concentrations from the same site, this meta-analysis quantitatively evaluated the relationship between soil and irrigation water As concentrations and the As concentration in the rice grain. A generalized linear regression model revealed As in soil to be a stronger predictor of As in rice than As in irrigation water (beta of 16.72 and 0.6, respectively, p < 0.01). Based on the better performing decision tree model, using soil and irrigation water As as independent variables we determined that Asian paddy soil As concentrations greater than 14 mg kg−1 may result in rice grains exceeding the Codex recommended maximum allowable inorganic As (i-As) concentrations of 0.2 mg kg−1 for polished rice and 0.35 mg kg−1 for husked rice. Both logistic regression and decision tree models, identified soil As as the main determining factor and irrigation water to be a non-significant factor, preventing determination of any guideline value for irrigation water. The seemingly non-significant contribution of irrigation water in predicting grain i-As concentrations below or above the Codex recommendation may be due to the complexity in the relationship between irrigation water As and rice grains. Despite modeling limitations and heterogeneity in meta-data, our findings can inform the maximum permissible As concentrations in Asian paddy soil.

Estimation of Fluoride Content of Drinking Water in Dharan

2020 ◽  
Vol 3 (1) ◽  
pp. 88-95
Author(s):  
Bandana Koirala ◽  
Surya Raj Niraula ◽  
Anup Ghimire
Keyword(s):  
Drinking Water ◽  
Dental Caries ◽  
Water Supply ◽  
Optimal Level ◽  
Fluoride Content ◽  
Water Supplies ◽  
Effective Measure ◽  
Guideline Value ◽  
Guideline Values ◽  
Significant Difference

Introduction: Fluoride when present in drinking water at optimal level has been shown to promote oral health by preventing tooth decay. Dental caries represents a health problem that impacts on the medical, functional, nutritional and psychological status of patients in all the age groups. Fluoridation of public water supply is a safe, economical and effective measure to prevent dental caries. Objective: To estimate the level of fluoride present in drinking water supplies in all the wards of Dharan and to compare the fluoride concentration of its different water supply sources. Methods: One hundred water samples were collected from the various sources (ground water and surface water) and its different reservoirs along with random samples of 2-7 from all the wards of Dharan. The samples were then taken to the SEAM-N-MMA laboratory, Biratnagar to be tested for fluoride using the photometric method. Microsoft excel for data entry and SPSS 11.5 version for analysis were used. Significance of the variables was examined by Chi-square test. Results: The results of this study showed that in 96% of the samples taken, fluoride level was below the optimal. Only few samples met the lower range guideline value of Nepal (0.5 mg/l). Also, there was significant difference (p< 0.002) between the surface and consumer level fluoride. Conclusion: The fluoride content in drinking water supplies of Dharan was found to be below optimal level as per the national and WHO guideline values.

scholarly journals A meta-analysis of published semivariograms to determine sample size requirements for assessment of heavy metal concentrations at contaminated sites

Soil Research ◽  
2019 ◽  
Vol 57 (4) ◽  
pp. 311 ◽  
Author(s):  
L. E. Pozza ◽  
T. F. A. Bishop
Keyword(s):  
Sample Size ◽  
Meta Analysis ◽  
Contaminated Sites ◽  
Metal Concentrations ◽  
Second Stage ◽  
Guideline Value ◽  
Guideline Values ◽  
The Mean ◽  
A Site ◽  
Specific Metal

Soil contamination poses substantial risks to human and ecosystem health, justifying the need for accurate delineation and remediation of contaminated sites. The number of soil samples collected at a site during assessment is limited by cost and time available for assessment, increasing the potential for misclassification due to insufficient samples. Using distributions of heavy metals sourced from semivariograms provided in published studies, the first stage of this study sought to determine how many samples were required for the confidence interval around the mean to be above or below the Australian guideline value for each specific metal and study. Estimated sample size for assessing mean contamination across a site ranged from two to four samples; however, some distributions possessed a higher amount of variation and therefore required more samples. The second stage of the investigation explored sample size requirements for mapping contaminated sites. Unconditional Gaussian simulations created from published semivariograms were sampled using 15 different sample sizes, and the samples used to obtain predictions of the simulated distributions. For each sample, observed (simulated) and predicted (kriged) metal concentrations were classed as being below or exceeding the guideline values and compared through quantification of the number of misclassifications that occurred. When mapping a site of 5 km2 or less, uncertainty and misclassification decreased with increasing sample size, stabilising at around 200 samples; however, the lowest uncertainty occurred at around 500 samples. The study acknowledges this may be unrealistic and economically inefficient, so in addition to these findings it is worth exploring improvement in other areas of investigation, such as in the detection and mapping stages.

scholarly journals Assessment of Drinking Water Quality of Madhyapur-Thimi and Study of Antibiotic Sensitivity against Bacterial Isolates

1970 ◽  
Vol 10 ◽  
pp. 167-172 ◽  
Author(s):  
Bina Laxmi Jayana ◽  
Tista Prasai ◽  
Anjana Singh ◽  
Kayo Devi Yami
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Samples ◽  
Enteric Bacteria ◽  
Drinking Water Quality ◽  
National Standard ◽  
Guideline Value ◽  
Guideline Values ◽  
Who Guideline

The study was undertaken to assess the existing status of drinking water quality of Madhyapur-Thimi. A total of 105 water samples comprising 50 (47.61%) wells, 45 (42.82%) tap water and 10 (9.52%) stone spouts were randomly collected. The physicochemical and microbiological parameters were analyzed following standard technique. The pH (1.9%), conductivity (34.28%) and turbidity (16.19%) of water samples had crossed the permissible guideline values as prescribed by WHO and national standard. All samples contained nitrate values within the WHO permissible value as well as national standard but hardness (2%), chloride (2.85%), iron (26.66%), ammonia (11.42%), and arsenic content (1.90%) crossed the WHO guideline value but none of the water samples crossed the national standard for arsenic. Arsenic having 0.025mg/l (25ppb) was detected from two well water samples, Makanani well and Ajimanani well. Total coliform count showed 64.76% of samples crossed the WHO guideline values. Eleven different kinds of enteric bacteria were isolated from different sources, Enterobacter spp. being the predominant. Isolates were subjected for antibiotic susceptibility pattern using ten antibiotics. Among total isolates, resistance was directed to 79.5% Erythromycin, 62.67% Penicillin G, 61.9% Amoxycillin, 34.5% Ampicillin, 21.1% Tetracycline, 15.4% Ceftriaxone, 14.7% Amikacin, 14.7% Cephotaxine, 5.6% Chlorophenical and 5.6% Ofloxacin respectively.Key words: Coliform; Enteric bacteria; Permissible value; Physicochemical; Antibiotic resistanceDOI: 10.3126/njst.v10i0.2955Nepal Journal of Science and Technology Vol. 10, 2009 Page: 167-172

scholarly journals Quality and Health Risk Assessment Associated with Water Consumption—A Case Study on Karstic Springs

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3510
Author(s):  
Ana Moldovan ◽  
Maria-Alexandra Hoaghia ◽  
Eniko Kovacs ◽  
Ionuț Cornel Mirea ◽  
Marius Kenesz ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Drinking Water ◽  
Health Risk ◽  
Health Risk Assessment ◽  
World Health ◽  
Oral Exposure ◽  
Water Supply Systems ◽  
Drinking Water Source ◽  
Guideline Value ◽  
Guideline Values

In rural areas without centralized water supply systems, inhabitants often use groundwater of unknown quality as drinking water, without understanding the possible negative consequences on their health. Karstic spring waters from Dobrogea region in Romania were assessed for their potential to be used as drinking water source, according to their quality and seasonal variation. The physico-chemical parameters of waters were compared with the guideline values for drinking water established by the World Health Organization and the Directive 98/83/EC. The nitrate and Cr concentrations exceeded the guideline value in the springs from Southern Dobrogea, but met the quality criteria in those from Northern Dobrogea, thus, to be used as drinking water, the karstic springs located in Southern Dobrogea require treatment for nitrates removal. Heavy metals pollution indices showed low to medium cumulative heavy metal pollution in all springs, while the human health risk assessment by oral exposure indicated possible noncarcinogenic risks of nitrates, both for adults and children in springs from South Dobrogea. A rigorous monitoring of the water quality before human consumption is recommended for all four studied water sources.

scholarly journals Factors influencing the relationship between fluoride in drinking water and dental fluorosis: a ten-year systematic review and meta-analysis

2019 ◽  
Vol 17 (6) ◽  
pp. 845-862 ◽  
Author(s):  
M. H. Akuno ◽  
G. Nocella ◽  
E. P. Milia ◽  
L. Gutierrez
Keyword(s):  
Systematic Review ◽  
Drinking Water ◽  
Dental Fluorosis ◽  
Meta Analysis ◽  
Developed Countries ◽  
World Health ◽  
The World ◽  
Health Organization ◽  
The Impact ◽  
The Relationship

Abstract The relationship between naturally fluoridated groundwater and dental fluorosis has received large attention from researchers around the world. Despite recognition that several factors influence this relationship, there is a lack of systematic studies analyzing the heterogeneity of these results. To fill such a gap, this study performs a systematic review and meta-analysis to understand which factors influence this relationship and how. Selected studies were sampled between 2007 and 2017 from Web of Science, PubMed, Google Scholar and Scopus using keywords and Boolean operators. Results of the systematic review show that dental fluorosis affects individuals of all ages, with the highest prevalence below 11, while the impact of other factors (gender, environmental conditions, diet and dental caries) was inconclusive. Meta-regression analysis, based on information collected through systematic review, indicates that both fluoride in drinking water and temperature influence dental fluorosis significantly and that these studies might be affected by publication bias. Findings show that fluoride negatively affects people's health in less developed countries. The conclusions discuss policy tools and technological innovations that could reduce fluoride levels below that of the World Health Organization (WHO) (&lt;1.5 mg/L).

scholarly journals Positive Association of Cardiovascular Disease (CVD) with Chronic Exposure to Drinking Water Arsenic (As) at Concentrations below the WHO Provisional Guideline Value: A Systematic Review and Meta-analysis

2020 ◽  
Vol 17 (7) ◽  
pp. 2536 ◽  
Author(s):  
Lingqian Xu ◽  
Debapriya Mondal ◽  
David A. Polya
Keyword(s):  
Systematic Review ◽  
Cardiovascular Disease ◽  
Drinking Water ◽  
Dose Response ◽  
Linear Models ◽  
Meta Analysis ◽  
Positive Association ◽  
P Value ◽  
Significant Positive Association ◽  
Guideline Value

To the best of our knowledge, a dose-response meta-analysis of the relationship between cardiovascular disease (CVD) and arsenic (As) exposure at drinking water As concentrations lower than the WHO provisional guideline value (10 µg/L) has not been published yet. We conducted a systematic review and meta-analyses to estimate the pooled association between the relative risk of each CVD endpoint and low-level As concentration in drinking water both linearly and non-linearly using a random effects dose-response model. In this study, a significant positive association was found between the risks of most CVD outcomes and drinking water As concentration for both linear and non-linear models (p-value for trend < 0.05). Using the preferred linear model, we found significant increased risks of coronary heart disease (CHD) mortality and CVD mortality as well as combined fatal and non-fatal CHD, CVD, carotid atherosclerosis disease and hypertension in those exposed to drinking water with an As concentration of 10 µg/L compared to the referent (drinking water As concentration of 1 µg/L) population. Notwithstanding limitations included, the observed significant increased risks of CVD endpoints arising from As concentrations in drinking water between 1 µg/L and the 10 µg/L suggests further lowering of this guideline value should be considered.

scholarly journals Spatiotemporal Patterns and Threshold of Chlorophyll-a in Lake Taihu Based on Microcystins

2021 ◽  
Author(s):  
xuemei fu ◽  
Mingxia Zheng ◽  
Jing Su ◽  
Beidou Xi ◽  
Daichun Wu ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Chlorophyll A ◽  
Lake Taihu ◽  
Water Quality Management ◽  
Water Security ◽  
Water Safety ◽  
Chl A ◽  
Guideline Value ◽  
Guideline Values

Abstract Chlorophyll-a (Chl- a ) is considered an indicator of phytoplankton biomass dynamically reflecting the growth of algae. Therefore, determination of Chl- a threshold is of vital importance to the health of aquatic ecosystems and drinking water security. This research is aimed to investigate the spatial and temporal distributions of Chl- a and microcystin (MC) concentrations using Geographic Information System (GIS) and identify the Chl- a threshold in Lake Taihu based on available guideline values of MCs. Nearly the same characteristics of spatiotemporal variation of Chl- a and MCs were observed in Lake Taihu. Overall, the lakewide distributions of Chl- a and MCs were highly variable over time and space. The Chl- a concentration in the winter and spring was relatively low, and gradually increasing in summer and autumn, with the maximum concentration observed in August. But the maximum MCs concentration appeared in October, two months lagging behind the Chl- a . The highest annual average Chl- a and MCs concentrations were observed in Zhushan Bay, Meiliang Bay, Gonghu Bay in northwest of Lake Taihu, following by West Zone and Center Zone. Dongtaihu Bay, East Zone and South Zone always present good water quality. Referring to the guideline value of MCs, the Chl- a threshold was determined as 10-15 mg·m -3 based on the linear regression correlation between Chl- a and MCs. The establishment of Chl- a threshold is useful for eutrophication control, water quality management and drinking water utilities in developing water safety plans.

scholarly journals Multivariate Analysis of Metal Levels in Paddy Soil, Rice Plants, and Rice Grains: A Case Study from Shakargarh, Pakistan

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Saadia R. Tariq ◽  
Nabila Rashid
Keyword(s):  
Paddy Soil ◽  
Principal Component ◽  
Atomic Absorption Spectrophotometry ◽  
Rice Grain ◽  
Rice Plants ◽  
Rice Grains ◽  
Metal Levels ◽  
And Cluster Analysis ◽  
The Given

The present study aims at determining the relationship between trace metal levels in paddy soils, rice plants, and rice grains obtained from these plants. The levels of selected metals (Fe, Co, Ni, Cd, Pb, and Cr) were determined by atomic absorption spectrophotometry in the soil, rice plants, and rice grain samples collected from paddy fields. All the metals were present at enhanced levels in paddy soil. Among the selected metals, Fe, Ni, Cd, and Cr were predominantly associated with oxidizable fraction. The metals such as Cr, Ni, Co, and Fe were significantly positively correlated in soil and plants, but no such correlation was observed in soil-grain matrix evidencing that these metals have a soil-based origin in the plants, but they were not translocated to grains. The Pb content of soil was strongly positively correlated with plants as well as the grains. The principal component analysis and cluster analysis were used to depict the origin of enhanced metal levels in rice plants. Under the given field conditions, different metals possess different translocation behaviours from soil to roots to shoots to grains. There is a dire need to implement the strategies for wise and optimum use of agrochemicals.

scholarly journals A Field Evidence of Cd, Zn and Cu Accumulation in Soil and Rice Grains after Long-Term (27 Years) Application of Swine and Green Manures in a Paddy Soil

2021 ◽  
Vol 13 (4) ◽  
pp. 2404
Author(s):  
Babar Hussain ◽  
Jumei Li ◽  
Yibing Ma ◽  
Yi Chen ◽  
Chunyan Wu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Paddy Soil ◽  
Green Manure ◽  
Swine Manure ◽  
Rice Grain ◽  
Green Manures ◽  
Organic Manures ◽  
Rice Grains ◽  
Zn And Cu In

Although inorganic and organic manures with high concentrations of heavy metals can lead to accumulation or contamination of heavy metals in soils, there are few reports on the effects of long-term application of swine and green manures on the accumulation of heavy metals in rice grains in paddy soils. A long-term field experiment, which was established in 1990 in paddy soil in Hangzhou, China, was used to investigate the effects of inorganic and organic manures on the availability and accumulation of heavy metals in soil and uptake by rice plant. The results showed that long-term application of nitrogen, phosphorus and potash (NPK) plus green manure or swine manure, and swine manure only increased 202%, 146%, and 100% for total Cd, and 5.5%, 7.6%, and 6.6% for total Cu in rice grains, respectively compared to the control without fertilization. Total Zn in rice grain was significantly increased by 13.9% for the treatment of NPK plus green manure. The accumulation of Cd, Zn, and Cu in rice grains after long-term application of swine and green manures is due to the combined effects of the increased concentrations of total and EDTA extractable Cd, Zn, and Cu in soil and the changes of soil properties. Furthermore, the highest bioconcentration factor for Cd was found in the treatment of NPK plus green manure while for Zn and Cu it was observed in NPK treatment. Thus, it may be concluded that green manure and manure with increased Cd, Zn, and Cu in rice grain results in a potential risk of metal accumulation in paddy soils.

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