Assessment of Health Risk from Fluoride Containment in Drinking Water

This report presents a health risk assessment of fluoride contamination in drinking water, focusing on the situation in Poldasht city, Iran. The study analyzed 112 water samples from 28 villages, revealing that 57% exceeded the permissible fluoride limit. The research details the exposure assessment, examining fluoride levels across different age groups and regions. It further assesses the adverse health effects, including dental and skeletal fluorosis, and calculates hazard quotients to characterize the associated risks. The report highlights that young children and teenagers are most at risk and recommends measures to reduce fluoride levels, emphasizing the need for enhanced monitoring to protect the population from fluorosis. The report also includes a detailed analysis of the hazard quotient for various age groups, emphasizing the need for interventions to mitigate the health risks associated with fluoride exposure.

Running head: ASSESSMENT OF HEALTH RISK OF FLUORIDE CONTAINMENT IN
DRINKING WATER
Health Risk Assessment
Name of the Student
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ASSESSMENT OF HEALTH RISK OF FLUORIDE CONTAINMENT IN DRINKING
WATER
Abstract:
The particular study aims to asses the health risk associated with the drinking water
containing the water pollutant fluoride is performed based on the statistical research done in
the water containment in Poldasht city which is in the northwest of Iran. The statistical
research was performed based on the collected one hundred and twelve samples of drinking
water from a total of 28 villages in the city. It has been found from the results that 57% of the
analysed samples exceeded the limit of fluoride containment in drinking water. The
maximum amount of fluoride exposure was found to the young children and the teenagers. In
this study the exposure range of fluoride to people of the city is presented and along with that
risk assessment is performed by calculating hazard quotient of the water. Based on the overall
research it is evident that suitable action should be performed to reduce the amount of
fluoride in the drinking water to save the population from fluorosis.

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ASSESSMENT OF HEALTH RISK OF FLUORIDE CONTAINMENT IN DRINKING
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Table of Contents
Introduction:...............................................................................................................................3
Exposure Assessment:................................................................................................................3
Adverse Effects Assessment:.....................................................................................................4
Risk Characterization:................................................................................................................5
Conclusion:................................................................................................................................8
Reference list:...........................................................................................................................10

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ASSESSMENT OF HEALTH RISK OF FLUORIDE CONTAINMENT IN DRINKING
WATER
Introduction:
Safe drinking water should be available to all the human beings but due to of some
chemicals like fluoride are present in the drinking water above a safe limit, the drinking water
becomes harmful to the people. Fluoride has been listed as one of the most prioritized
hazardous substance as identified by the US Agency for Toxic Substances and Disease
Registry. The fluoride mainly enters the human body via drinking water (Yousefi, Ghoochani
& Mahvi, 2018). Many researchers found that the human body absorbs almost 90% of the
fluoride from the drinking water, whereas, only 30 to 40% of fluoride is absorbed from the
food. While, tooth damage is prevented by a standard concentration of fluoride but an
excessive concentration of fluoride can lead to several health diseases. The adverse effects in
health include tooth decay at a level of 0.5 mg/L fluoride in drinking water. When the density
of the fluoride in drinking water is between 1.5 to 5 mg/L fluorosis occurs and at a more
higher level the skeleton fluorosis occurs when the fluoride concentration is between 5 to 40
mg/day. If the drinking water contains 10 mg of fluoride-exposed to a child from birth to
adult stage then it can cause genu recurvate and other problems like hypertension,
neurological problems, infertility, cancer, arthritis Alzheimer's and thyroid (Bus et al., 2015).
Also, as recommended by the World Health Organization the limit of fluoride concentration
in water is about 0.5 to 1.5 mg/L which does not cause any harm to the body. The fluoride
concentration is much more than the standard level in the Poldasht City of Northwest Iran as
found by the early researches. Hence, the fluoride content in the drinking water of the 28
villages are analyzed in this research and the adverse effects with the risk associated with the
current situation in the city are represented in the later stages.

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ASSESSMENT OF HEALTH RISK OF FLUORIDE CONTAINMENT IN DRINKING
WATER
Exposure Assessment:
In this part of the research the exposure of fluoride to the people of 28 villages in
Poldasht city are analyzed. The study sample has been obtained from the springs and the
wells of 28 villages of the Poldasht City. Initially a total of one hundred and twelve water
samples were collected from the village in a period of 6 months from 2014 to 2016. The
samples of the water are collected in containers made from plastic and then those are
transported to the research laboratory to analyze the samples. Now, according to standard
instruction the density of fluoride in the water was determined by the SPADNS method
which is also known as Zirconium Lake Method (Ludwicki et al., 2015). The fluoride
concentration in between the range 0.0625 to 1.75 mg/L are determined in this method and
the higher concentrations are diluted and then measured (Arora, Kumar & Moss,2018). The
concentration of the fluoride has been assessed by using the spectrophotometer and the
determination limit is 0.12 ppm and the quantification limit is 0.37 ppm.
Adverse Effects Assessment:
If the fluoride ion is consumed at a high level for a long duration then it can cause
chronic toxicity that can lead to Fluorosis in dental or at skeletal level. By the research it has
been found by one factor Analysis of Variance(ANOVA) of the sample data that fluoride
exposure in significantly different in different regions (Yousefi, Ghoochani & Mahvi, 2018).
The results show that only 11% of the sample received fluoride exposure less than the limit as
identified by the WHO. This particular value prevents the cavity in the tooth. The exposure
levels in different regions of the city are represented below.

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ASSESSMENT OF HEALTH RISK OF FLUORIDE CONTAINMENT IN DRINKING
WATER
Figure 1: Exposure level of Fluoride for different age groups and different regions in
Poldasht city
The safety limits of Fluoride exposure as defined by the WHO is 0.4 mg per day for the
infants, 0.7 mg per day for the children and 4 mg per day for the adults.
Risk Characterization:
Determination of the adverse health effects to the human body is the motive of the
health risk characterization and the assessment process. Now, the health risk assessment of
fluoride by consumption of the drinking water is assessed in the rural region of the Poldasht
city. By collecting the water samples from the taps of the villages and then subdividing the
population into four main groups based on the difference in psychology and behaviour
(Guissouma et al., 2017). The four groups are infants who are less than 2 years, children in
between 2 to less than 6 years, the teenagers in the range 6 to less than 16 years and finally
the adults more than 16 years. The fluoride exposure has been calculated by using the
following formula

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ASSESSMENT OF HEALTH RISK OF FLUORIDE CONTAINMENT IN DRINKING
WATER
EDI= Cf ∗Cd
Bw
The daily average drinking water consumption, density of Fluoride in the drinking water and
weight of the body gives the Estimated Daily Intake of the fluoride as given in the above
formula (Craig et al., 2015). The expression of EDI is mg per kg of the bodyweight in each
day. The consumption of fluoride data and the weight of the body were predicted based on
the responses of the groups (Waghmare et al., 2015). The response statistics was the mean
amount of water consumption of different groups named as, children, teenagers, infants and
the adults are,0.85, 2, 0.08 and 2.5 L/day respectively (Peckham, Lowery, & Spencer, 2015).
Similarly, the body weights of the target groups are 10 for infants, 15 for children, 50 for
teenager and 78 kg for the adults. The hazard quotient represents the non-carcinogenic risk of
fluoride that is given by,
HQ= EDI
RFD
The dose of the reference as used in the assessment of risk is given by the daily limit of
exposure to the human population. The reference doses of the fluoride are 0.06 mg/kg/day
which are found from Integrated Risk Information System database (Nishimuro et al., 2015).
If the HQ value is less than one then this means that there is lower chance of experiencing
adverse health effects (Choi et al., 2015). If the HQ value is more than 1 then that means the
risk is more than the acceptable level and there is a chance of health issues.
The density of fluoride in drinking water taps are represented with mean and tolerance in
Poldasht city.

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ASSESSMENT OF HEALTH RISK OF FLUORIDE CONTAINMENT IN DRINKING
WATER
Table 1: The density of fluoride in drinking water of Poldasht City as expressed by
means ± sd
Village Mean ± sd(mg/L) Min (mg/L) Max(mg/L)
Pomak 2.44±0.72 1.95 3.21
Ghoulish lanamish 2.24±0.52 1.58 2.87
Moradlo vasati 1.73±0.34 1.44 1.91
Nazok sofla 0.63±0.02 0.58 0.62
Gharghlogh sofla 1.95±0.52 1.55 2.4
Ghir kendi 1.62±0.09 1.54 1.67
Nazok olyia 0.8±0.20 0.57 1.01
Shiblo olia 0.84±0.27 0.48 1.16
Divankhane 1.25±1.16 0.42 2.04
Ghare jalo 1.68±0.03 1.67 1.6
Shahrak aras 0.69±0.21 0.46 0.81
Moradlo olia 2.46±0.76 1.93 3.01
Eshg abad 1.84±0.20 1.68 2.07
The hazard quotient as calculated in different regions and for different age groups as
presented below.

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ASSESSMENT OF HEALTH RISK OF FLUORIDE CONTAINMENT IN DRINKING
WATER
Figure 2: Value of Hazard Quotient for different cities and different age groups
Conclusion:
Hence, the identified water pollutant Fluoride has several impacts on health as found
from the research article which was conducted in Poldasht city of Northwest Iran. It has been
found from the research that the concentration level of fluoride in the different Poldasht city
villages was 0.27 to 10.3 mg/L and the sample average was 1.70 mg/L. As analysed from the
collected sample 57% of the drinking water samples crossed the set limit of fluoride in the
drinking water. Hence, some tools of rapid decision-making are needed to decrease the health
problems by reducing the density of fluoride in drinking water. Also, it was found in the city
that mostly the young, teenagers and children are exposed by the fluoride. The drinking water
contaminated by the fluoride also higher than the HQ level of 1 for all the age groups in
Sarioo region. Hence, it is recommended that to take suitable measures for reducing the
density of fluoride in drinking water and then to control the fluorosis. Suitable actions needed

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ASSESSMENT OF HEALTH RISK OF FLUORIDE CONTAINMENT IN DRINKING
WATER
be implemented for enhancing the fluoride monitoring levels for avoiding the risk associated
with the population.

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WATER
Reference list:
Arora, S., Kumar, J. V., & Moss, M. E. (2018). Does water fluoridation affect the
prevalence of enamel fluorosis differently among racial and ethnic groups?. Journal of public
health dentistry, 78(2), 95-99.
Bus, J. S., Banton, M. I., Faber, W. D., Kirman, C. R., McGregor, D. B., & Pourreau,
D. B. (2015). Human health screening level risk assessments of tertiary-butyl acetate
(TBAC): Calculated acute and chronic reference concentration (RfC) and Hazard Quotient
(HQ) values based on toxicity and exposure scenario evaluations. Critical reviews in
toxicology, 45(2), 142-171.
Choi, A. L., Zhang, Y., Sun, G., Bellinger, D. C., Wang, K., Yang, X. J., ... &
Grandjean, P. (2015). Association of lifetime exposure to fluoride and cognitive functions in
Chinese children: a pilot study. Neurotoxicology and teratology, 47, 96-101.
Craig, L., Lutz, A., Berry, K. A., & Yang, W. (2015). Recommendations for fluoride
limits in drinking water based on estimated daily fluoride intake in the Upper East Region,
Ghana. Science of the Total Environment, 532, 127-137.
Guissouma, W., Hakami, O., Al-Rajab, A. J., & Tarhouni, J. (2017). Risk assessment
of fluoride exposure in drinking water of Tunisia. Chemosphere, 177, 102-108.
Ludwicki, J. K., Góralczyk, K., Struciński, P., Wojtyniak, B., Rabczenko, D., Toft,
G., ... & Czaja, K. (2015). Hazard quotient profiles used as a risk assessment tool for PFOS
and PFOA serum levels in three distinctive European populations. Environment international,
74, 112-118.

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Nishimuro, H., Ohnishi, H., Sato, M., Ohnishi-Kameyama, M., Matsunaga, I., Naito,
S., ... & Saitoh, S. (2015). Estimated daily intake and seasonal food sources of quercetin in
Japan. Nutrients, 7(4), 2345-2358.
Peckham, S., Lowery, D., & Spencer, S. (2015). Are fluoride levels in drinking water
associated with hypothyroidism prevalence in England? A large observational study of GP
practice data and fluoride levels in drinking water. J Epidemiol Community Health, 69(7),
619-624.
Waghmare, S. S., Arfin, T., Manwar, N., Lataye, D. H., Labhsetwar, N., & Rayalu, S.
(2015). Preparation and characterization of polyalthia longifolia based alumina as a novel
adsorbent for removing fluoride from drinking water. Asian J. Adv. Basic Sci, 4(1), 12-24.
Yousefi, M., Ghoochani, M., & Mahvi, A. H. (2018). Health risk assessment to
fluoride in drinking water of rural residents living in the Poldasht city, Northwest of Iran.
Ecotoxicology and environmental safety, 148, 426-430.