Scalp Hair as Biomarker for Chronic Fluoride Exposure among Fluoride Endemic and Low Fluoride Areas: A Comparative Study

OBJECTIVE: To investigate scalp hair as biomarker for chronic fluoride exposure among fluoride endemic and low fluoride areas. METHODOLOGY: Two areas were identified in Vadodara district, Ajod, as a low fluoride area (Fluoride content of drinking water = 0.11 ppm) and Karsan, a high fluoride area (fluoride content in drinking water = 3.43 ppm). The study was performed on a total of 36 participants from the two villages, 18 from Ajod and 18 from Karsan. Thylstrup Fejerskov Index (TFI) was recorded for each of the participants and sample of hair was collected from the occipital region. Analysis of hair samples was done for assessing the fluoride content. RESULTS: The study consisted of total 36 participants, ranging from the age of 34–60 years and a mean age of 46.53 years. The mean TFI score for the participants in Karsan was 3.39 (±0.979) and in Ajod was 0.83 (±0.786). The difference in this mean score between the two groups was found to be statistically significant. Furthermore, the average fluoride content in hair of the participants in Karsan was 3.40(±1.043) and that in Ajod was 0.35 (±0.063). This difference was statistically significant between the two groups. The TFI scores were found to be positively correlated with the fluoride content in hair. CONCLUSION: Hair can be used as a useful biomaterial for fluoride exposure monitoring. Having certain advantages over other biomaterials such as easy to collect, store, and transport, hair also serves as a biomarker of chronic fluoride exposure. Hair analysis should thus play a greater role in routinely measuring the chronic exposure to fluorides.