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Health risk assessment to fluoride in drinking water of rural residents living in the Poldasht city, Northwest of Iran
Ecotoxicology and Environmental Safety 148 (2018) 426–430
Contents lists available at ScienceDirect
Ecotoxicology and Environmental Safety journal homepage: www.elsevier.com/locate/ecoenv
Health risk assessment to fluoride in drinking water of rural residents living in the Poldasht city, Northwest of Iran Mahmood Yousefia, Mahboobeh Ghoochania, Amir Hossein Mahvia,b, a b
MARK
⁎
Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Center for Solid Waste Research, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran
A R T I C L E I N F O
A B S T R A C T
Keywords: Fluoride Drinking water Risk assessment Fluorosis Poldasht
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 10.3 mg L−1 (average 1.70 mg L−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.
1. Introduction Access to safe drinking water is the natural right of all human beings and is one of the key development indicators. The presence of some chemical elements in drinking water at concentrations above the standard levels could lead to the health problems in the long-term. One of these chemicals is fluorine is an abundant element in the environment (Fawell et al., 2006; Aldrees and Al-Manea, 2010). According to US EPA fluoride is one of the twelve pollutants and it has been listed in the priority hazardous substances with US Agency for Toxic Substances and Disease Registry (Faraji et al., 2014; Aghaei et al., 2015; Mahvi et al., 2006). Fluoride enters the body in various ways, such as drinking water, breathing and food uptake. The most important source of human contact with fluoride is through drinking water (Dobaradaran et al., 2009). Many studies showed that the drinking water is the major source of daily fluoride exposure in Iran (Taghipour et al., 2016). Also in according to studies, about 90% of fluoride exists in drinking water is absorbed in the digestive system, while only 30–60% of fluoride exists in the food is absorbed in the digestive system (WHO, 1996). The standard level of fluoride in drinking water prevents in averages 40% of tooth decay. Since 1951 the United States Public Health Service Administration has been adding fluoride to the public source of drinking water in areas where fluoride concentrations are lower compared with standard levels (Guissouma et al., 2017). However, it has been shown that high concentration of fluoride has adverse health effects. Many
⁎
adverse effects are including tooth decay at concentrations of less than 0.5 mg L−1 of fluoride in drinking water, fluorosis in long-term use of drinking water containing fluoride when concentration is in the range of 1.5–5 mg L−1 in drinking water, skeletal fluorosis when the concentration of fluoride in drinking water is 5–40 mg day−1, drinking water containing 10 mg of fluoride from birth to adolescence causes genu recurvate and other health problem such as hypertension, infertility, neurological problems, Alzheimer's, thyroid, cancer, and arthritis has been reported in related with high concentrations of fluoride (Nouri et al., 2006; Fordyce et al., 2007; Boldaji et al., 2009; Rahmani et al., 2010; Amouei et al., 2012; Dobaradaran et al., 2011; Bazrafshan et al., 2012; Asghari et al., 2017). The Health Canada reported values 122 and 200 µg kg−1 bw day−1 of fluoride levels might cause to dental fluorosis and skeletal fluorosis. The 60 µg kg−1 bw day−1 of fluoride level set by US-EPA to prevent the dental fluorosis (Guissouma et al., 2017). Also, the World Health Organization (WHO) has recommended 0.5–1.5 mg L−1 to prevent the adverse effects of fluoride in drinking water. And also, the concentration of 0.5–1 mg L−1 fluoride in drinking water suggested to prevent tooth decay (WHO, 1996; Fordyce et al., 2007). Iran is a developing country with fluorite domains. In some regions, fluoride concentrations are higher than the standard levels. The Poldasht city is one of these areas where located in the northwest of Iran. A study was conducted in Bohlol abad village showed fluoride content in drinking water was above the standard level (Karimzade et al., 2014). Therefore, we determined the fluoride content of drinking
Corresponding author at: Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. E-mail address: [email protected] (A. Hossein Mahvi).
http://dx.doi.org/10.1016/j.ecoenv.2017.10.057 Received 12 September 2017; Received in revised form 20 October 2017; Accepted 25 October 2017 0147-6513/ © 2017 Elsevier Inc. All rights reserved.
Ecotoxicology and Environmental Safety 148 (2018) 426–430
M. Yousefi et al.
kilometers. The population of subjected villages was shown in the Table 1(Fig. 1)
Table 1 The population of villages of Poldasht. Village name
Population
Village name
Population
Pomak Moradlo vasati Ghoulish lanamish Gharghlogh sofla Nazok sofla Nazok olyia Ghir kendi Divankhane Shiblo olia Shahrak aras Ghare jalo Eshg abad Moradlo olia Sarisoo
539 275 1111 348 286 420 282 480 278 1944 499 323 183 779
Gharghologh olia Zakerlo Shidi Hasan kandi Orooj mohammad Bohlol abad Ghoch kandi Tape pashi Chakhmaghlo sofla Eshgh abad Dailan kandi Agh otlogh Bohlol kandi Shotloo
171 630 946 771 463 1363 1115 387 348 323 1207 462 848 719
2.2. Determination of fluoride in drinking water The samples of this study were taken from drinking water resources including wells and springs from 28 villages of the city. A total of 112 samples were collected every six month over two consecutive years from March 2014 to March 2016. The water samples were collected in the sterile plastic containers and then transported to the laboratory. Fluoride concentration of water samples was determined using SPADNS method according to instruction of Standard. Analytical method for fluoride determination in the range of 0.0625–1.75 mg L−1 (r = 0.9993) and the higher concentrations of this range were diluted and measured. The fluoride concentration was assessed by Spectrophotometer (DR/5000, USA) and obtained limits of determination (LOD) and quantification (LOQ) were 0.12 ppm and 0.37 ppm respectively.
water in 28 villages of the Poldasht from March 2014 to March 2016. And also, we assessed the potential risks from fluoride ingestion through drinking water for infants, children, teenagers and adults. The findings of this study could be useful for future planning of water resources as well as public knowledge about health problems related with fluoride high concentrations.
2.3. Risk assessment of fluoride A human health risk assessment is the process to estimate the nature and probability of adverse health effects in humans who may be exposed to chemicals in contaminated environmental media, now or in the future. So, the quantitative health risk assessment of fluoride through consumption of drinking water was evaluated in rural population of Poldasht city, West Azerbaijan Province. For this purpose, tap water samples were taken from different villages. We divided population into four age groups based on physiological and behavioral differences as same as Ghoochani et al. study (Ghoochani et al., 2017) as fallow: infants (less than 2 years), children (2 to < 6 years), teenagers (6 to < 16 years) and adults (≥ 16 years). Exposure to fluoride was calculated in these groups using Eq. (1):
2. Material and methods 2.1. Study areas Poldasht city is located in North West Azerbaijan province of Iran and North Western with coordinates (UTM) X = 446,625–513,055 to the east and Y = 4,344,280–4,402,863 is located north latitude. Poldasht meteorological station showed that in a long-term, the average rainfall was equal to 131.5 mm. The city has also borderline from West and North with Turkey. According to the national statistics of Iran, the urban population of Poldasht is 8584 and 66 villages of Poldasht have 27,778 rural population. It also has an area of 72,870 square
EDI =
Cf × Cd Bw
(1) Fig. 1. Location of the study areas in Poldasht City, West Azerbaijan, Iran.
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Ecotoxicology and Environmental Safety 148 (2018) 426–430
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Estimated Daily intake (EDI) of F is calculated based on the daily average consumption of drinking water (Cd), concentration of F in drinking water (Cf) and body weight (Bw). EDI is expressed in unit of milligrams per kilogram of bodyweight per day. The water consumption data and body weight were estimated based on a questionnaire that were asked of the target groups (infants, children, teenager and adults). The average water consumption rates in infants (0–2 years old), children (2–6 years old), teenagers (6–16 years old) and adults (≥ 16 years old) were 0.08, 0.85, 2 and 2.5 L day−1, respectively. Body weight of target groups were considered 10, 15, 50 and 78 kg, respectively. The non-carcinogenic risk of fluoride to human health can be expressed as hazard quotient (HQ) using Eq. (2):
HQ =
EDI RfD
Table 2 The fluoride concentration in tap drinking water in villages of the Poldasht, expressed as means ± standard deviation, min and max.
(2)
The reference dose (RfD) is used in risk assessments and it is an estimate of a daily exposure to the human population that is likely to be without an appreciable risk of deleterious effects during a lifetime. The oral reference doses of F (0.06 mg kg−1 d−1) were obtained from the data-base of Integrated Risk Information System, USEPA (USEPA, IRIS U). The HQ is the ratio between the EDI and RfD; an HQ value less than one indicates that it is unlikely even for sensitive populations to experience adverse health effects. When the value of HQ is larger than 1, it indicates that the non-carcinogenic risk excesses the acceptable level and adverse health effects are possible. 2.4. Statistical analysis All descriptive statistics such as average, standard deviation, minimum and maximum for the subjected parameters were estimated by using the Excel 2016 software. Statistical analysis such as one-way ANOVA test analysis was done by SPSS (IBM Corp. Released 2016. IBM SPSS Statistics for Windows, Version 24.0. Armonk, NY: IBM Corp.). Pvalues less than 0.05 considered statistically significant.
Village
Mean ± Sd (mg L−1)
Min(mg L−1)
Max(mg L−1)
Pomak Moradlo vasati Ghoulish lanamish Gharghlogh sofla Nazok sofla Nazok olyia Ghir kendi Divankhane Shiblo olia Shahrak aras Ghare jalo Eshg abad Moradlo olia Sarisoo Gharghologh olia Zakerlo Shidi Hasan kandi Orooj mohammad Bohlol abad Ghoch kandi Tape pashi Chakhmaghlo sofla Eshgh abad Dailan kandi Agh otlogh Bohlol kandi Shotloo
2.44 ± 0.67 1.73 ± 0.24 2.23 ± 0.49 1.93 ± 0.50 0.61 ± 0.03 0.7 ± 0.19 1.59 ± 0.08 1.23 ± 1.16 0.84 ± 0.27 0.69 ± 0.21 1.68 ± 0.03 1.84 ± 0.20 2.46 ± 0.76 7.68 ± 1.24 1.84 ± 0.41 0.35 ± 0.10 0.64 ± 0.31 0.69 ± 0.12 1.83 ± 0.18 1.79 ± 0.23 0.75 ± 0.04 1.63 ± 0.19 0.54 ± 0.03 1.7 ± 0.05 2.1 ± 0.10 8.3 ± 2.83 0.29 ± 0.03 0.28 ± 0.01
1.96 1.46 1.59 1.54 0.59 0.56 1.53 0.41 0.49 0.45 1.66 1.69 1.92 6.81 1.54 0.28 0.42 0.57 1.71 1.58 0.73 1.5 0.52 1.66 2.03 6.3 0.27 0.28
3.2 1.92 2.88 2.5 0.63 1.02 1.68 2.05 1.17 0.82 1.7 2.06 3 8.56 2.31 0.42 0.86 0.8 1.96 2.04 0.78 1.77 0.56 1.76 2.17 10.3 0.31 0.29
consumption of water with a high fluoride amount in Zacatecas, Mexico. Zhang et al. reported the highest non-carcinogenic risk of fluoride risk were in children group. They divided exposed Chinese populations to three groups as fallow: children (0–10 years), teenagers (11–20 years) and adults (21–72 years). The adverse risks of F found for children > teenagers ~ adults. The results were somewhat similar to the finding of our study (Huang et al., 2017). The results of Guissouma et al. (2017) showed that young consumers (infants and children) were more exposed to health risk of fluoride in Tunisia. Based on results, children of 4 villages (Pormak, Moradlo Olia, Agh Otlogh and Sarisoo) might exposed to dental fluorosis. The fluoride exposure was above the values recommended by Health Canada (122 µg kg−1 bw day−1). Also, children of 16 of 28 villages (57%) have exposure levels of fluoride above the value recommended by US-EPA (60 µg kg−1bw day−1), which might cause dental fluorosis. The calculated EDI level of fluoride in target groups of two villages (Agh Otlogh and Sarisoo) observed more than 200 µg kg−1 bw day−1. The skeletal fluorosis might occur based on recommended value by Health Canada. Figs. 4 and 5 be taken of some resident in these regions that well represented these issues. In all mentioned villages, the HQ value was more than 1. The HQ value was obtained much more than 1 in all of target groups in Agh Otlogh and Sarisoo villages. The 95th percentile risk values for target groups exceeded the safe level of 1. Therefore, the vulnerable residents was potentially exposed to non-carcinogenic risks. Therefore, these area should receive more health concerns and especial measures must be taken to decrease the adverse health effects on the local population.
3. Results and discussion We evaluated the fluoride concentration in villages of Poldasht. Table 2 shows all mean, maximum and minimum levels of fluoride concentrations. One factor analysis of variance (ANOVA) of the data showed that level of fluoride in different villages was significantly different among the different village water samples in different locations (P < 0.05). Based on results, the population of 3 of 28 villages (11%) receive fluoride concentrations less than the limit recommended by WHO of 0.5 mg L1. This value prevents the tooth cavity. Fluoride exposure levels for different rural population was observed in four age groups as Fig. 2. The fluoride exposure of rural population indicated that the young groups (children and teenager) had high level of EDI as compared to infants and adults. Also, the HQ value for young groups was higher than 1 in Fig. 3. For each studied area, the non-carcinogenic risks of fluoride for the four exposed populations varied: children > teenagers > adults > infants. Consequently, these groups of young people can consider as hyper sensitive population. Brahman et al. (2014) investigated fluoride exposure through water consumption in Nagarparker, Pakistan. They divided population in three groups. Understudy age groups were 7–15 years, 16–25 years and 26–50 years. The results showed that younger age group (7–15 years) were at the sever risk of fluorosis as compared to elder groups. The study of Chen et al. (2016) assessed health risk of F in rural residents (infants, children and adults) living in a region of Northwest China. They reported infants were the most vulnerable group. Also, they found that majority of samples on infants (72%) and children (60%) exposed to adverse impact of fluoride. The study of Martínez-Acuña et al. (2016) showed that children had a higher risk of health effects through
4. Conclusion The concentration levels of fluoride in water resources in the villages of Poldasht city was 0.27–10.3 mg L−1 and the average of samples was 1.70 mg L−1. The 57% of samples analyzed exceeded the limit set for fluoride in drinking water. The results from health risk assessment indicate a quick decision-making tools to decrease environmental 428
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Exposure Level (mg Kg-1 bw day-
Fig. 2. Fluoride exposure levels for different regions of Poldasht city over four age groups (infants, children, teenager and adults).
Location
Hazard Quotient
Fig. 3. Hazard Quotient value for different regions of Poldasht city over four age groups (infants, children, teenager and adults).
Location Fig. 4. Examples of dental fluorosis in two villages of the Poldasht. 4A: age: 7, sex: male, village: Sarisoo: 4B: age: 6, sex: female, village: Pormak.
and Sarioo areas. Based on results, it is imperative to take measures to reduce F 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. Acknowledgements The authors want to thank authorities of Poldasht health center for their contributions to the collection of information. Conflict of interest Fig. 5. Example of skeletal fluorosis in Agh Otlogh village, age: 40, sex: male.
The authors of this article declare that they have no conflict of interests.
health problems. Based on findings from 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, but the calculated HQ value was > 1 for all groups of residents in Agh otlogh
References Aghaei, M., et al., 2015. Hypertension and Fluoride in Drinking Water: Case Study from West Azerbaijan, Iran. Hypertension.
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Tehran. Iran. Water Sci. Technol.: Water Supply 17, 958–965. Guissouma, W., et al., 2017. Risk assessment of fluoride exposure in drinking water of Tunisia. Chemosphere 177, 102–108. Huang, D., et al., 2017. Probabilistic risk assessment of Chinese residents' exposure to fluoride in improved drinking water in endemic fluorosis areas. Environ. Pollut. 222, 118–125. IRIS U. , June 2017. Integrated Risk Information System, USEPA 〈https://cfpubepagov/ ncea/iris/search/indexcfm?keyword=fluoride.8〉. Karimzade, S., et al., 2014. Investigation of intelligence quotient in 9-12-year-old children exposed to high-and low-drinking water fluoride in West Azerbaijan Province, Iran. Fluoride 47, 9–14. Mahvi, A., et al., 2006. Survey of fluoride concentration in drinking water sources and prevalence of DMFT in the 12 years old students in Behshar City. J. Med. Sci. 6, 658–661. Martínez-Acuña, M.I., et al., 2016. Preliminary human health risk assessment of arsenic and fluoride in tap water from Zacatecas, México. Environ. Monit. Assess. 188, 476. Nouri, J., et al., 2006. Regional pattern distribution of groundwater fluoride in the Shush aquifer of Khuzestan County, Iran. Fluoride 39, 321. Rahmani, A., et al., 2010. Child dental caries in relation to fluoride and some inorganic constituents in drinking water in Arsanjan, Iran. Fluoride 43, 179–186. Taghipour, N., et al., 2016. National and sub-national drinking water fluoride concentrations and prevalence of fluorosis and of decayed, missed, and filled teeth in Iran from 1990 to 2015: a systematic review. Environ. Sci. Pollut. Res. 23, 5077–5098. WHO, 1996. Trace Elements in Human Nutrition and Health Geneva: World Health Organization. World Health Organization.
Aldrees, A.M., Al-Manea, S.M., 2010. Fluoride content of bottled drinking waters available in Riyadh, Saudi Arabia. Saudi Dent. J. 22, 189–193. Amouei, A., et al., 2012. Fluoride concentration in potable groundwater in rural areas of Khaf city, Razavi Khorasan Province, Northeastern Iran. Int. J. Occup. Environ. Med. 3. Asghari, F.B., et al., 2017. Data on fluoride concentration levels in cold and warm season in rural area of Shout (West Azerbaijan, Iran). Data Brief. Bazrafshan, E., et al., 2012. Application of electrocoagulation process using Iron and Aluminum electrodes for fluoride removal from aqueous environment. J. Chem. 9, 2297–2308. Boldaji, M.R., et al., 2009. Evaluating the effectiveness of a hybrid sorbent resin in removing fluoride from water. Int. J. Environ. Sci. Technol. 6, 629–632. Brahman, K.D., et al., 2014. Fluoride and arsenic exposure through water and grain crops in Nagarparkar. Pak. Chemosphere 100, 182–189. Chen, J., et al., 2016. Assessing nitrate and fluoride contaminants in drinking water and their health risk of rural residents living in a semiarid region of northwest china. Expo. Health 1–13. Dobaradaran, S., et al., 2009. Particulate airborne fluoride from an aluminium production plant in Arak, Iran. Fluoride 42, 228. Dobaradaran, S., et al., 2011. Fluoride in skin and muscle of two commercial species of fish harvested off the Bushehr shores of the Persian Gulf. Fluoride 44, 143. Faraji, H., et al., 2014. Correlation between fluoride in drinking Water and its levels in breast milk in Golestan Province, Northern Iran. Iran. J. Public Health 43, 1664. Fawell, J., et al., 2006. Fluoride in Drinking-Water. WHO. Fordyce, F., et al., 2007. A health risk assessment for fluoride in Central Europe. Environ. Geochem. Health 29, 83–102. Ghoochani, M., et al., 2017. Risk assessment of haloacetic acids in the water supply of
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Contents lists available at ScienceDirect
Ecotoxicology and Environmental Safety journal homepage: www.elsevier.com/locate/ecoenv
Health risk assessment to fluoride in drinking water of rural residents living in the Poldasht city, Northwest of Iran Mahmood Yousefia, Mahboobeh Ghoochania, Amir Hossein Mahvia,b, a b
MARK
⁎
Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Center for Solid Waste Research, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran
A R T I C L E I N F O
A B S T R A C T
Keywords: Fluoride Drinking water Risk assessment Fluorosis Poldasht
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 10.3 mg L−1 (average 1.70 mg L−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.
1. Introduction Access to safe drinking water is the natural right of all human beings and is one of the key development indicators. The presence of some chemical elements in drinking water at concentrations above the standard levels could lead to the health problems in the long-term. One of these chemicals is fluorine is an abundant element in the environment (Fawell et al., 2006; Aldrees and Al-Manea, 2010). According to US EPA fluoride is one of the twelve pollutants and it has been listed in the priority hazardous substances with US Agency for Toxic Substances and Disease Registry (Faraji et al., 2014; Aghaei et al., 2015; Mahvi et al., 2006). Fluoride enters the body in various ways, such as drinking water, breathing and food uptake. The most important source of human contact with fluoride is through drinking water (Dobaradaran et al., 2009). Many studies showed that the drinking water is the major source of daily fluoride exposure in Iran (Taghipour et al., 2016). Also in according to studies, about 90% of fluoride exists in drinking water is absorbed in the digestive system, while only 30–60% of fluoride exists in the food is absorbed in the digestive system (WHO, 1996). The standard level of fluoride in drinking water prevents in averages 40% of tooth decay. Since 1951 the United States Public Health Service Administration has been adding fluoride to the public source of drinking water in areas where fluoride concentrations are lower compared with standard levels (Guissouma et al., 2017). However, it has been shown that high concentration of fluoride has adverse health effects. Many
⁎
adverse effects are including tooth decay at concentrations of less than 0.5 mg L−1 of fluoride in drinking water, fluorosis in long-term use of drinking water containing fluoride when concentration is in the range of 1.5–5 mg L−1 in drinking water, skeletal fluorosis when the concentration of fluoride in drinking water is 5–40 mg day−1, drinking water containing 10 mg of fluoride from birth to adolescence causes genu recurvate and other health problem such as hypertension, infertility, neurological problems, Alzheimer's, thyroid, cancer, and arthritis has been reported in related with high concentrations of fluoride (Nouri et al., 2006; Fordyce et al., 2007; Boldaji et al., 2009; Rahmani et al., 2010; Amouei et al., 2012; Dobaradaran et al., 2011; Bazrafshan et al., 2012; Asghari et al., 2017). The Health Canada reported values 122 and 200 µg kg−1 bw day−1 of fluoride levels might cause to dental fluorosis and skeletal fluorosis. The 60 µg kg−1 bw day−1 of fluoride level set by US-EPA to prevent the dental fluorosis (Guissouma et al., 2017). Also, the World Health Organization (WHO) has recommended 0.5–1.5 mg L−1 to prevent the adverse effects of fluoride in drinking water. And also, the concentration of 0.5–1 mg L−1 fluoride in drinking water suggested to prevent tooth decay (WHO, 1996; Fordyce et al., 2007). Iran is a developing country with fluorite domains. In some regions, fluoride concentrations are higher than the standard levels. The Poldasht city is one of these areas where located in the northwest of Iran. A study was conducted in Bohlol abad village showed fluoride content in drinking water was above the standard level (Karimzade et al., 2014). Therefore, we determined the fluoride content of drinking
Corresponding author at: Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. E-mail address: [email protected] (A. Hossein Mahvi).
http://dx.doi.org/10.1016/j.ecoenv.2017.10.057 Received 12 September 2017; Received in revised form 20 October 2017; Accepted 25 October 2017 0147-6513/ © 2017 Elsevier Inc. All rights reserved.
Ecotoxicology and Environmental Safety 148 (2018) 426–430
M. Yousefi et al.
kilometers. The population of subjected villages was shown in the Table 1(Fig. 1)
Table 1 The population of villages of Poldasht. Village name
Population
Village name
Population
Pomak Moradlo vasati Ghoulish lanamish Gharghlogh sofla Nazok sofla Nazok olyia Ghir kendi Divankhane Shiblo olia Shahrak aras Ghare jalo Eshg abad Moradlo olia Sarisoo
539 275 1111 348 286 420 282 480 278 1944 499 323 183 779
Gharghologh olia Zakerlo Shidi Hasan kandi Orooj mohammad Bohlol abad Ghoch kandi Tape pashi Chakhmaghlo sofla Eshgh abad Dailan kandi Agh otlogh Bohlol kandi Shotloo
171 630 946 771 463 1363 1115 387 348 323 1207 462 848 719
2.2. Determination of fluoride in drinking water The samples of this study were taken from drinking water resources including wells and springs from 28 villages of the city. A total of 112 samples were collected every six month over two consecutive years from March 2014 to March 2016. The water samples were collected in the sterile plastic containers and then transported to the laboratory. Fluoride concentration of water samples was determined using SPADNS method according to instruction of Standard. Analytical method for fluoride determination in the range of 0.0625–1.75 mg L−1 (r = 0.9993) and the higher concentrations of this range were diluted and measured. The fluoride concentration was assessed by Spectrophotometer (DR/5000, USA) and obtained limits of determination (LOD) and quantification (LOQ) were 0.12 ppm and 0.37 ppm respectively.
water in 28 villages of the Poldasht from March 2014 to March 2016. And also, we assessed the potential risks from fluoride ingestion through drinking water for infants, children, teenagers and adults. The findings of this study could be useful for future planning of water resources as well as public knowledge about health problems related with fluoride high concentrations.
2.3. Risk assessment of fluoride A human health risk assessment is the process to estimate the nature and probability of adverse health effects in humans who may be exposed to chemicals in contaminated environmental media, now or in the future. So, the quantitative health risk assessment of fluoride through consumption of drinking water was evaluated in rural population of Poldasht city, West Azerbaijan Province. For this purpose, tap water samples were taken from different villages. We divided population into four age groups based on physiological and behavioral differences as same as Ghoochani et al. study (Ghoochani et al., 2017) as fallow: infants (less than 2 years), children (2 to < 6 years), teenagers (6 to < 16 years) and adults (≥ 16 years). Exposure to fluoride was calculated in these groups using Eq. (1):
2. Material and methods 2.1. Study areas Poldasht city is located in North West Azerbaijan province of Iran and North Western with coordinates (UTM) X = 446,625–513,055 to the east and Y = 4,344,280–4,402,863 is located north latitude. Poldasht meteorological station showed that in a long-term, the average rainfall was equal to 131.5 mm. The city has also borderline from West and North with Turkey. According to the national statistics of Iran, the urban population of Poldasht is 8584 and 66 villages of Poldasht have 27,778 rural population. It also has an area of 72,870 square
EDI =
Cf × Cd Bw
(1) Fig. 1. Location of the study areas in Poldasht City, West Azerbaijan, Iran.
427
Ecotoxicology and Environmental Safety 148 (2018) 426–430
M. Yousefi et al.
Estimated Daily intake (EDI) of F is calculated based on the daily average consumption of drinking water (Cd), concentration of F in drinking water (Cf) and body weight (Bw). EDI is expressed in unit of milligrams per kilogram of bodyweight per day. The water consumption data and body weight were estimated based on a questionnaire that were asked of the target groups (infants, children, teenager and adults). The average water consumption rates in infants (0–2 years old), children (2–6 years old), teenagers (6–16 years old) and adults (≥ 16 years old) were 0.08, 0.85, 2 and 2.5 L day−1, respectively. Body weight of target groups were considered 10, 15, 50 and 78 kg, respectively. The non-carcinogenic risk of fluoride to human health can be expressed as hazard quotient (HQ) using Eq. (2):
HQ =
EDI RfD
Table 2 The fluoride concentration in tap drinking water in villages of the Poldasht, expressed as means ± standard deviation, min and max.
(2)
The reference dose (RfD) is used in risk assessments and it is an estimate of a daily exposure to the human population that is likely to be without an appreciable risk of deleterious effects during a lifetime. The oral reference doses of F (0.06 mg kg−1 d−1) were obtained from the data-base of Integrated Risk Information System, USEPA (USEPA, IRIS U). The HQ is the ratio between the EDI and RfD; an HQ value less than one indicates that it is unlikely even for sensitive populations to experience adverse health effects. When the value of HQ is larger than 1, it indicates that the non-carcinogenic risk excesses the acceptable level and adverse health effects are possible. 2.4. Statistical analysis All descriptive statistics such as average, standard deviation, minimum and maximum for the subjected parameters were estimated by using the Excel 2016 software. Statistical analysis such as one-way ANOVA test analysis was done by SPSS (IBM Corp. Released 2016. IBM SPSS Statistics for Windows, Version 24.0. Armonk, NY: IBM Corp.). Pvalues less than 0.05 considered statistically significant.
Village
Mean ± Sd (mg L−1)
Min(mg L−1)
Max(mg L−1)
Pomak Moradlo vasati Ghoulish lanamish Gharghlogh sofla Nazok sofla Nazok olyia Ghir kendi Divankhane Shiblo olia Shahrak aras Ghare jalo Eshg abad Moradlo olia Sarisoo Gharghologh olia Zakerlo Shidi Hasan kandi Orooj mohammad Bohlol abad Ghoch kandi Tape pashi Chakhmaghlo sofla Eshgh abad Dailan kandi Agh otlogh Bohlol kandi Shotloo
2.44 ± 0.67 1.73 ± 0.24 2.23 ± 0.49 1.93 ± 0.50 0.61 ± 0.03 0.7 ± 0.19 1.59 ± 0.08 1.23 ± 1.16 0.84 ± 0.27 0.69 ± 0.21 1.68 ± 0.03 1.84 ± 0.20 2.46 ± 0.76 7.68 ± 1.24 1.84 ± 0.41 0.35 ± 0.10 0.64 ± 0.31 0.69 ± 0.12 1.83 ± 0.18 1.79 ± 0.23 0.75 ± 0.04 1.63 ± 0.19 0.54 ± 0.03 1.7 ± 0.05 2.1 ± 0.10 8.3 ± 2.83 0.29 ± 0.03 0.28 ± 0.01
1.96 1.46 1.59 1.54 0.59 0.56 1.53 0.41 0.49 0.45 1.66 1.69 1.92 6.81 1.54 0.28 0.42 0.57 1.71 1.58 0.73 1.5 0.52 1.66 2.03 6.3 0.27 0.28
3.2 1.92 2.88 2.5 0.63 1.02 1.68 2.05 1.17 0.82 1.7 2.06 3 8.56 2.31 0.42 0.86 0.8 1.96 2.04 0.78 1.77 0.56 1.76 2.17 10.3 0.31 0.29
consumption of water with a high fluoride amount in Zacatecas, Mexico. Zhang et al. reported the highest non-carcinogenic risk of fluoride risk were in children group. They divided exposed Chinese populations to three groups as fallow: children (0–10 years), teenagers (11–20 years) and adults (21–72 years). The adverse risks of F found for children > teenagers ~ adults. The results were somewhat similar to the finding of our study (Huang et al., 2017). The results of Guissouma et al. (2017) showed that young consumers (infants and children) were more exposed to health risk of fluoride in Tunisia. Based on results, children of 4 villages (Pormak, Moradlo Olia, Agh Otlogh and Sarisoo) might exposed to dental fluorosis. The fluoride exposure was above the values recommended by Health Canada (122 µg kg−1 bw day−1). Also, children of 16 of 28 villages (57%) have exposure levels of fluoride above the value recommended by US-EPA (60 µg kg−1bw day−1), which might cause dental fluorosis. The calculated EDI level of fluoride in target groups of two villages (Agh Otlogh and Sarisoo) observed more than 200 µg kg−1 bw day−1. The skeletal fluorosis might occur based on recommended value by Health Canada. Figs. 4 and 5 be taken of some resident in these regions that well represented these issues. In all mentioned villages, the HQ value was more than 1. The HQ value was obtained much more than 1 in all of target groups in Agh Otlogh and Sarisoo villages. The 95th percentile risk values for target groups exceeded the safe level of 1. Therefore, the vulnerable residents was potentially exposed to non-carcinogenic risks. Therefore, these area should receive more health concerns and especial measures must be taken to decrease the adverse health effects on the local population.
3. Results and discussion We evaluated the fluoride concentration in villages of Poldasht. Table 2 shows all mean, maximum and minimum levels of fluoride concentrations. One factor analysis of variance (ANOVA) of the data showed that level of fluoride in different villages was significantly different among the different village water samples in different locations (P < 0.05). Based on results, the population of 3 of 28 villages (11%) receive fluoride concentrations less than the limit recommended by WHO of 0.5 mg L1. This value prevents the tooth cavity. Fluoride exposure levels for different rural population was observed in four age groups as Fig. 2. The fluoride exposure of rural population indicated that the young groups (children and teenager) had high level of EDI as compared to infants and adults. Also, the HQ value for young groups was higher than 1 in Fig. 3. For each studied area, the non-carcinogenic risks of fluoride for the four exposed populations varied: children > teenagers > adults > infants. Consequently, these groups of young people can consider as hyper sensitive population. Brahman et al. (2014) investigated fluoride exposure through water consumption in Nagarparker, Pakistan. They divided population in three groups. Understudy age groups were 7–15 years, 16–25 years and 26–50 years. The results showed that younger age group (7–15 years) were at the sever risk of fluorosis as compared to elder groups. The study of Chen et al. (2016) assessed health risk of F in rural residents (infants, children and adults) living in a region of Northwest China. They reported infants were the most vulnerable group. Also, they found that majority of samples on infants (72%) and children (60%) exposed to adverse impact of fluoride. The study of Martínez-Acuña et al. (2016) showed that children had a higher risk of health effects through
4. Conclusion The concentration levels of fluoride in water resources in the villages of Poldasht city was 0.27–10.3 mg L−1 and the average of samples was 1.70 mg L−1. The 57% of samples analyzed exceeded the limit set for fluoride in drinking water. The results from health risk assessment indicate a quick decision-making tools to decrease environmental 428
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Exposure Level (mg Kg-1 bw day-
Fig. 2. Fluoride exposure levels for different regions of Poldasht city over four age groups (infants, children, teenager and adults).
Location
Hazard Quotient
Fig. 3. Hazard Quotient value for different regions of Poldasht city over four age groups (infants, children, teenager and adults).
Location Fig. 4. Examples of dental fluorosis in two villages of the Poldasht. 4A: age: 7, sex: male, village: Sarisoo: 4B: age: 6, sex: female, village: Pormak.
and Sarioo areas. Based on results, it is imperative to take measures to reduce F 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. Acknowledgements The authors want to thank authorities of Poldasht health center for their contributions to the collection of information. Conflict of interest Fig. 5. Example of skeletal fluorosis in Agh Otlogh village, age: 40, sex: male.
The authors of this article declare that they have no conflict of interests.
health problems. Based on findings from 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, but the calculated HQ value was > 1 for all groups of residents in Agh otlogh
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