Fluoride in fish flesh, fish bone and regular diet in south-coastal area of Karnataka state of India

Background: The objective of the study was to estimate the fluoride content in regular food items available, including fish, in a coastal area of the South Karnataka state of India. Materials and Methods: Fish and food samples were collected from a local market, i.e., Deralakatte, Mangalore of Karnataka State, India. Commonly consumed different species of fish (eight types are included in the study) and popular food items (twelve types) were collected through a random sampling strategy and then processed for the study. The flesh and bones of fish were separated from individual fish. Samples of flesh, bones, and food (nonfish, vegetarian food consumed by a proportion of Karnataka population) were homogenized separately, dried, and the pH of the processed samples was adjusted to neutrality (pH 7.0). Fluoride anion was determined using a fluoride ion selective electrode (ISE, Nico2000 Ltd., UK). Although the ingredients of the different fish and food items explored differed, the same processing technique and analytical laboratory bench-work procedure were performed for each sample, i.e., as per published research elsewhere. This ensured the accurate estimation of fluoride for each food item. Results: Concentrations of fluoride in foods (Nonfish, vegetarian food) was estimated to ranging from 0.85 to 7.09 ppm and that in fish samples ranged from 1.45 to 2.30 ppm. The highest concentration was estimated 3.16 ppm in Rohu fish flesh, and 7 ppm in rava dosa (a vegetarian food). Conclusion: In conclusion, the Rohu (Labeo rohita) fish species were found to contain higher concentrations of bone fluoride. Fluoride determined in fish flesh was also high in concentration 2.28 ppm. Among the regular food items, rava dosa (a thin and crispy crepe made from rava and rice flour) preparation has a higher level of fluoride. These values would provide valid information regarding the future development of recommended dietary allowance strategy for a population