Distribution of fluoride contamination in drinking water resources and health risk assessment using geographic information system, northwest Iran.

This paper considers exposure to the concentration of fluoride in drinking water resources of Showt city in West Azerbaijan Province in, Iran, and its related potential health risk assessment issues to the resident populations. For this purpose, 88 drinking water samples were analyzed in 2016 by using the spectrophotometric method. Non-carcinogenic health risks due to F exposure through consumption of drinking water were assessed using the US EPA method. In addition, the associated zoning maps of the obtained results were presented using a geographic information system (GIS). The results indicated that fluoride concentration in drinking water ranged from 0.0 to 5.5 mg L-1 of the study area. Based on this research, 36.36% of the samples had a fluoride level higher than the permissible level, 13.63% had less than the permissible limit, and 50% of the samples had a level within the optimum limit of 0.5-1.5 mg L-1. The Hazard Quotient index (HQ) for children, teenager and adults had health hazards (HQ > 1) in 54.55%, 31.82%, and 22.73% of samples, respectively. Groundwater resources having a risk of more than one were located in the villages of Khilajajam, Kolos, and Shorboulagh. So, in these study areas, there are potential risks of dental and skeletal fluorosis.

Health risk assessment to fluoride in drinking water of rural residents living in the Poldasht city, Northwest of Iran.

This study analyzes the concentrations and health risks of fluoride in 112 drinking water samples collected from 28 villages of the Poldasht city, West Azerbaijan province in Iran. Results indicated that fluoride content in drinking water ranged from0.27 to 10.3mgL-1 (average 1.70mgL-1). The 57% of samples analyzed exceeded the limit set for fluoride in drinking water. Based on findings from health risk assessment this study, the highest fluoride exposure for different regions of Poldasht city was observed in young consumers, children and teenager's groups. Also, most of the rural residents suffered from fluoride contaminated drinking water. The calculated HQ value was > 1 for all groups of residents in Agh otlogh and Sari soo areas. Therefore, it is imperative to take measures to reduce fluoride concentration in drinking water and control of fluorosis. Action should be implemented to enhance monitoring of fluoride levels to avoid the potential risk to the population.

Nanocellulose: A comprehensive review investigating its potential as an innovative material for water remediation.

Rapid growth in industrialization sectors, the wastewater treatment plants become exhausted and potentially not able to give desirable discharge standards. Many industries discharge the untreated effluent into the water bodies which affects the aquatic diversity and human health. The effective disposal of industrial effluents thus has been an imperative requirement. For decades nanocellulose based materials gained immense attraction towards application in wastewater remediation and emerged out as a new biobased nanomaterial. It is light weighted, cost effective, mechanically strong and easily available. Large surface area, versatile surface functionality, biodegradability, high aspect ratio etc., make them suitable candidate in this field. Majorly cellulose based nanomaterials are used in the form of cellulose nanocrystals (CNCs), cellulose nanofibers (CNFs), or bacterial nanocellulose (BNC). This review specifically describes about a variety of extraction methods to produced nanocellulose and also discusses the modification of nanocellulose by adding functionalities in its surface chemistry. We majorly focus on the utilization of nanocellulose based materials in water remediation for the removal of different contaminants such as dyes, heavy metals, oil, microbial colony etc. This review mainly emphasizes in ray of hope towards nanocellulose materials to achieve more advancement in the water remediation fields.

The Effectiveness of Fluoride Varnish and Fissure Sealant in Elementary School Children: A Systematic Review and Meta-Analysis.

Background: Highly necessary to evaluate the effectiveness of preventive interventions to prioritize them at the community level. We aimed to systematically investigate the related studies on the effects of fluoride varnish and fissure sealant on dental caries in 6-12 children. Methods: We searched PubMed, EMBASE, Web of Science, Cochrane Library and Scopus databases using Fluoride Varnish, Fissure Sealant, Caries, and Oral Health keywords. The timeframe selected to search for articles is from 2000 to Dec 2020. CMA software: 2 (Comprehensive Meta-Analysis) was used to perform the meta-analysis. The intervention groups in this study were fluoride varnish and fissure sealants, each of them compared to the control groups. Results: We included nine studies. In the intervention group 84,380 and control group 11,254 individuals were studied. Eight of the studies were Randomized Clinical Trial (RCT) and Field RCT, and two was non-RCT. In the overall Fluoride Varnish efficacy study, 4 were fully effective, 1 was ineffective, and all 4 were completely effective for Fissure Sealant. There was a significant difference between decayed, missing, and filled permanent teeth (DMFT) and decayed, missing, and filled primary teeth (dmft) indices in both interventions and comparison groups. Moreover, the mean difference of DMFT for Fluoride Varnish and Fissure Sealant in the intervention and control groups were -0.55 and -0.29, respectively (P=0.00). Conclusion: Due to the efficacy of fissure sealant and fluoride varnish in preventing dental caries in children aged 6-12 yr, these interventions can be considered as health priorities of societies and health systems interventions in countries.

Preparation of a cellulose acetate membrane using cigarette butt recycling and investigation of its efficiency in removing heavy metals from aqueous solution.

This study investigated the recycling of freshly-smoked cigarette butts (FCBs) and unsmoked cigarette filters (UCFs) into a cellulose acetate (CA) membrane. The both samples were prepared by means of a combination of seven cigarette brands, and the phase inversion method was used to recycle each sample into a membrane using N-methyl-2-pyrrolidone. The efficiency of the prepared membranes for the removal of chromium, cadmium, and lead from an aqueous solution in a forward osmosis reactor was investigated. The results showed that the both membranes had a smooth surface and macrovoids. The flux of the prepared membranes from the UCFs and FCBs recycling were 14.8 and 13.2 LMH, respectively. The porosity and reverse salt of the UCFs membrane were 61% and 3.5 gMH, while those for FCBs membrane were 58% and 3.9 gMH. The observed metal removal efficiency of the both membranes was in the range of 85 to 90%. However, increasing the concentration of metals up to five times caused a slight decrease in the removal efficiency (less than 5%).

Spatial Distribution Variation and Probabilistic Risk Assessment of Exposure to Fluoride in Ground Water Supplies: A Case Study in an Endemic Fluorosis Region of Northwest Iran.

Prevalence of fluorosis is a worldwide public health issue, especially in the West Azerbaijan province of Iran. The aim of this study was to investigate fluoride concentration in drinking water resources within Maku city, in both the warm and cold seasons, to perform a health risk assessment. Fluoride were measured using UV-visible spectrophotometry. The spatial distribution was calculated by the software ArcGIS and Hazard Quotients (HQs) were calculated according to the US EPA method. The fluoride concentrations ranged between 0.29 to 6.68 and 0.1 to 11.4 mg/L in the cold and warm seasons, respectively. Based on this report, 30.64 and 48.15% of the samples revealed a fluoride level higher than the permissible level in the cold and warm seasons, respectively. Moreover, results showed that the HQ value in the warm season for different age groups was higher than the HQ value in the cold season. In both seasons, the non-carcinogenic risks of fluoride for the four exposed populations varied according to the order: children > teenagers > adults > infants. The HQ values for three age groups (children, teenager and adults) for both seasons were higher than 1 with a high risk of fluorosis. The results of this study, support the requests that government authorities better manage water supplies to improve health quality.

Non-Carcinogenic Health Risk Assessment due to Fluoride Exposure from Tea Consumption in Iran Using Monte Carlo Simulation.

Excessive intake of fluoride can cause adverse health effects. Consumption of tea as a popular drink could be a potential source of fluoride exposure to humans. This research aimed to evaluate the fluoride concentration in tea among the Iranian people using the available data in the literature and to assess the health risk related to the consumption of tea in men, women, and children. The health risk assessment was conducted using the chronic daily intake and hazard quotient according to the approach suggested by the Environmental Protection Agency. The fluoride content in published studies varied noticeably, ranging from 0.13 to 3.27 mg/L. The results revealed that the hazard quotient (HQ) in age groups of women (21-72 years) and children (0-11 years) was within the safe zone (HQ < 1) which showed that there was no potential of non-carcinogenic risk associated with drinking tea in these groups. However, in one case of the men (21-72 years), the HQ > 1 which shows a probable risk of fluorosis. The order of non-carcinogenic health risks in the studied groups was in the order of men > women > children. The results of this can be useful for organizations with the responsibility of human health promotion.

Data on fluoride concentration in drinking water resources in Iran: A case study of Fars province; Larestan region.

Fluoride is a natural element among minerals, geochemical sediments and natural water systems which is entered to body chain by drinking water. Groundwater is the main and the best source of drinking water in southern areas of Iran especially in the cities of Lar and Gerash (Fars province). So due to the health significance fluoride including dental and skeletal fluorosis, fertility, abortion and thyroid diseases, etc., measuring has high importance in the water resources of this region of Iran. Fluoride concentration was 0.35-3.46 mg/L and 78.26% drinking water sources contains fluoride concentration above the WHO guideline.

Data on fluoride concentration levels in cold and warm season in City area of Sistan and Baluchistan Province, Iran.

The need for fluoride in drinking water to the extent that reduces the amount of tooth decay and the other hand does not cause dental fluorosis, has been well documented as an important fact. The aim of this research is to survey values of fluoride in drinking water in Sistan and Baluchestan. In this descriptive and analytical study, the number of 551 samples during 4 seasons of 2013 year from rural drinking water sources via rural water and Wastewater Company has been taken. The concentration of fluoride in water samples was measured using SPADNS method. Results shows that the average concentration of fluoride in drinking water supplies for the rural region of Khash, Sarbaz, Iranshahr, Saravan, Nickshahr city are 0.72 (±0.31), 0.55(±0.21), 0.33 (±0.127), 0.6 (±0.24), 0.435 (±0.23) respectively.

Fluoride concentration level in rural area in Poldasht city and daily fluoride intake based on drinking water consumption with temperature.

Long-term exposure to high level of fluoride can caused several adverse effects on human health including dental and skeletal fluorosis. We investigated all the drinking water source located in rural areas of Poldasht city, west Azerbaijan Province, North West Iran between 2014 and 2015. Fluoride concentration of water samples was measured by SPADNS method. We found that in the villages of Poldasht the average of fluoride concentration in drinking water sources (well, and the river) was in the range mg/l 0.28-10.23. The average daily received per 2 l of drinking water is in the range mg/l 0.7-16.6 per day per person. Drinking water demands cause fluorosis in the villages around the area residents and based on the findings of this study writers are announced suggestions below in order to take care of the health of area residents.

Skeletal fluorosis in relation to drinking water in rural areas of West Azerbaijan, Iran.

Skeletal fluorosis resulting from high fluoride level in drinking water is a major public health problem. The present study evaluated the association between exposures to drinking water fluoride and skeletal fluorosis in 5 villages of Poldasht County, Iran. All the data and information on the prevalence of bone diseases were obtained from the Health Record Department, Poldasht Health Centre. To obtain the odds ratio of bone disease problem in different risk factors, when considering the cluster effect of rural area, logistic regression in a multilevel model was used. Results showed that skeletal fluorosis of people who live in areas with high fluoride concentration is 18.1% higher than that of individuals who live in areas with low fluoride concentration. Skeletal fluorosis (54.5%) was observed in the age group of 71 years and above, and was more commonly found in females than males. According to Unadjusted, individuals who consume ≤3 unit milk and dairy products per week have almost the same level of bone diseases as compared to those that consume more than 3 units. This study indicated that, skeletal fluorosis is a general health problem in these rural areas because the results revealed that high percentage of the studied population had symptoms of skeletal fluorosis.