Mean Fluoride Concentration in Drinking Water Sources of a Municipality: A Descriptive Cross-sectional Study

Chronic Fluoride Exposure Induces Ovarian Dysfunction and Potential Association with Premature Ovarian Failure in Female Rats

Chronic fluorosis has been widely investigated for its adverse effects on skeletal and neurological health; however, its impact on reproductive health, especially in females, remains underexplored. In this study, female Sprague-Dawley rats were exposed to different fluoride concentrations (0.75, 50, and 100 mg/L) in their drinking water for six months. Dental fluorosis and increased urinary fluoride content were observed in fluoride-exposed rats, reflecting fluoride accumulation and exposure levels. Chronic fluorosis resulted in reduced ovary organ coefficient, indicating harmful effects on ovarian tissue. Additionally, the number of ovarian primordial and primary/secondary follicles decreased, while the number of atresia follicles increased. Furthermore, chronic fluorosis led to disrupted estrous cycles. Hormonal analysis revealed altered secretion of estrogen, progesterone, anti-Müllerian hormone, luteinizing hormone, follicular stimulating hormone, and inhibin B in response to fluoride exposure. Ultrastructural observation of ovarian granulosa cells showed evidence of apoptosis, which was further confirmed by flow cytometry. Caspase-3 activity was increased, and ATP levels were decreased, suggesting mitochondrial impairment and apoptosis induction. The mRNA and protein expression of BMP15 and GDF9, essential regulators of ovarian function, significantly decreased with increasing fluoride concentration. Furthermore, gene expression analysis identified a panel of premature ovarian failure-related genes that were downregulated in fluoride-exposed rat ovaries. These findings suggest that chronic fluoride exposure may contribute to ovarian dysfunction and possibly the pathogenesis of premature ovarian failure. Understanding the toxicological effects of chronic fluoride exposure on ovarian function is essential for identifying potential environmental risk factors affecting female reproductive health.

Effect of Drinking Water Fluoride on Gingivitis and Caries: A Study in Peat and Non-Peat Land: A Comparative Cross-Sectional Study

Aim

Humans get fluoride from food and water available in their environment. The source of clean water in peatlands comes from rainwater with a low mineral content, especially fluoride. The objective of this study was to investigate the correlation between the fluoride level in drinking water and salivary fluoride levels, as well as their potential impact on dental and oral health conditions.

Materials and Methods

It is a causal-comparative study with a cross-sectional approach at the Health Polytechnics of Pontianak and Yogyakarta. The population were indigenous people in peat land (Pontianak) and non-peat land (Yogyakarta). The data were pH and mineral content in drinking water, saliva, the number of Streptococcus mutans colonies, dental caries rates, and gingivitis.

Results

Drinking water fluoride is only significantly correlated with salivary fluoride on non-peat land. If these data are combined, it can be seen that drinking water fluoride is positively correlated (P < 0.05; CI 95%) with pH water, fluoride water, and pH saliva. Increased levels of fluoride in drinking water were negatively correlated with gingivitis, dental caries, and S. mutans.

Conclusion

Drinking water fluoride is negatively correlated with dental caries and gingivitis in peatland and non-peatland communities, but would be significantly associated with dental caries and gingivitis if both peatland and non-peatland data were analyzed together. This is due to the low content of fluoride in the drinking water of peatland. Therefore, it is necessary to add fluoride gel to the teeth to prevent the development of dental caries.