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Association of fluoride exposure with disease burden and neurodevelopment outcomes in children in South Korea

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Abstract

Background

Community water fluoridation is an effective public health strategy for preventing dental caries, yet. Concerns exist about potential health problems. This study explores associations between tap water fluoride levels and pediatric disease burden, as well as neurodevelopmental outcomes at 6 years of age.

Methods

This nationwide population-based cohort study included children born in Korean cities with and without tap water fluoridation projects, between 2006 and 2012, aiming for a fluoride concentration of 0.8 ± 0.2 mg/L in treated tap water. Data from the National Health Insurance Service were used, spanning from birth to 2018. The relationship between exposure to fluoridated tap water and incidence of 16 childhood diseases that were previously identified as potentially linked to fluoride exposure were examined. Additionally, we evaluated the neurodevelopmental outcomes across various domains, including gross motor, fine motor, cognition, language, social skills, and self-help functions. These assessments were performed using data from a comprehensive national health screening program for children aged six years.

Results

A fluoride-unexposed group included 22,881 children, whereas a fluoride-exposed group comprised 29,991 children (52% males). Children in the fluoride-exposed group had a decreased risk of dental caries and bone fractures [hazard ratio (95% confidence interval, CI), 0.76 (0.63–0.93) and 0.89 (0.82–0.93), respectively] and increased risk of hepatic failures [1.85, (1.14–2.98)] compared to those in the unexposed group. Additionally, the risk ratio of abnormal neurodevelopmental screening outcomes increased by 9%, but this was statistically uncertain (95% CI, 0.95–1.26).

Conclusions

Fluoridated tap water was associated with an increased risk of hepatic failure but a decreased risk of bone fractures in children. The association between fluoridated tap water and neurodevelopmental screening outcomes at 6 years remains unclear, highlighting the need for further studies to clarify this association.

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Data availability

This study was based on the National Health Claims Database (NHIS-2019–1-560), established by the NHIS of the Republic of Korea. Applications using NHIS data were reviewed by the Inquiry Committee of Research Support. If an application is approved, raw data are provided to the applicant for a fee. We cannot provide access to the data, analytical methods, or research materials to other researchers because the intellectual property rights of this database are owned by the National Health Insurance Corporation. However, investigators who wish to reproduce our results or replicate the procedure can be included in the database, which is open for research purposes (https://nhiss.nhis.or.kr/).

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Funding

This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HR22C1605), and by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2022R1A2C2005916).

Author information

Authors and Affiliations

  1. Department of Pediatrics, CHA Ilsan Medical Center, CHA University School of Medicine, Goyang, Republic of Korea

    Won Seok Lee

  2. Department of Pediatrics, Kyung Hee University Hospital, Kyung Hee University College of Medicine, Seoul, Republic of Korea

    Ju Hee Kim

  3. Department of Pediatrics, CHA Bundang Medical Center, CHA University School of Medicine, 59 Yatap-Ro, Bundang-Gu, Seongnam-si, Gyeonggi-do, 13496, Republic of Korea

    Boeun Han & Man Yong Han

  4. Multi-Omics Research Center, CHA Future Medicine Research Institute, Seongnam, Republic of Korea

    Boeun Han

  5. Department of Computer Science and Engineering, Konkuk University, Seoul, Republic of Korea

    Gi Chun Lee

  6. School of Medicine, CHA University, Pocheon, Republic of Korea

    Hye Ri Jung & Ye ** Shin

  7. Department of Pediatrics, Hallym University Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Republic of Korea

    Eun Kyo Ha

  8. Department of Pediatrics, Chonnam National University Hospital, Chonnam National University Medical School, Gwangju, Republic of Korea

    Eun Lee

  9. Department of Orthopaedic Surgery, CHA Bundang Medical Center, CHA University School of Medicine, 59 Yatap-Ro, Bundang-Gu, Seongnam-si, Gyeonggi-do, 13496, Republic of Korea

    Soonchul Lee

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  1. Won Seok Lee
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Contributions

LWS, KJH: conceptualization, writing–original draft. HMY: conceptualization, formal analysis. HBE, LKC, JHR, SYJ, HEK, LE and LSC: investigation, supervision. All authors discussed the results and contributed to the final manuscript. LWS and KJH contributed equally to this paper.

Corresponding author

Correspondence to Man Yong Han.

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Conflict of interest

No financial or non-financial benefits have been received or will be received from an party related directly or indirectly to the subject of this article.

Ethical approval

This study was conducted in accordance with the guidelines of the Declaration of Helsinki and approved by the Institutional Review Board of the Korea National Institute for Bioethics Policy (P01-201603–21-005).

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The waiver of informed consent from participants and all data from the Korean National Health Insurance Service (NHIS) and National Health Screening Program for Infants and Children (NHSPIC) were anonymized.

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Lee, W.S., Kim, J.H., Han, B. et al. Association of fluoride exposure with disease burden and neurodevelopment outcomes in children in South Korea. World J Pediatr (2024). https://doi.org/10.1007/s12519-024-00820-3

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