Fluoride Exposure Via Drinking Water on Adolescents and its Associated Health Effects

Abstract

The issue of underground water contamination by fluoride has gained significant global attention due to its detrimental effects on public health. Geological processes, such as the presence of minerals like cryolite, fluorite, and other fluorine-bearing minerals, contribute to the deterioration of underground water quality. Extensive research conducted in various regions worldwide has revealed several health risks associated with fluoride exposure, including dental and skeletal fluorosis, neurotoxicity, and adverse effects on liver and kidney function. This growing concern emphasizes the necessity for comprehensive scientific investigations and appropriate interventions to mitigate the risks linked to fluoride contamination in underground water sources. The impacts of elevated fluoride levels on various regions in Pakistan have been observed, particularly regarding the toxic effects of fluoride on the liver and kidneys of adolescents. For this study, rural areas in the districts of Lahore and Kasur were selected. The study encompassed a total of 119 participants who were categorized into two main groups: the exposed group and the control group. Within the exposed group, participants were further divided into four subgroups based on the fluoride concentration in the water: low (≥1.5 mg/L), medium (≥4 mg/L), high (≥6 mg/L), and very high (≥8 mg/L). Ninety-three participants resided in areas with high fluoride concentrations, while twenty-five participants belonged to the control area of the study. A questionnaire was administered to the participants, collecting information on general demographics (age, gender, duration of residence in the area), presence of dental fluorosis, and family history of liver and kidney diseases. The fluoride levels in the water were measured on-site using a Hanna Low range fluoride meter, while fluoride levels in urine were determined using a fluoride ion selective electrode. Blood samples ix were obtained from the participants for the analysis of liver and kidney parameters, which were analyzed using a chemistry analyzer. Urine samples were also collected to measure fluoride levels. The results indicated elevated levels of fluoride in both water and urine samples. Dental fluorosis was found to be prevalent in the area. Statistical analysis demonstrated that dental fluorosis was not significantly associated with gender or age variations. Furthermore, the findings revealed that fluoride accumulation had an impact on hepatic biomarkers, particularly alanine aminotransferase (ALT) and aspartate aminotransferase (AST), in the participants belonging to the very high fluoride exposure group. However, no significant relationship was observed between nephrotoxicity and gender or age of the participants. Notably, statistical analysis indicated significant differences in urea, serum creatinine and estimated glomerular filtration rate (eGFR) levels among the various fluoride exposed groups. It should be noted that the present study did not include smokers; however, a few participants had secondhand smoke exposure. A comparison between participants with secondhand smoke exposure and those without smoking exposure revealed a statistically significant difference in urea levels between the two groups. Considering the health impacts observed in this study, there is an urgent need to educate the population and implement effective policies to address water pollution in these areas. Key Words: Dental fluorosis, skeletal fluorosis. Neurotoxicity, adolescents, Liver, Kidney