Estimation of fluoride uptake in soil and staple food crops produced in highly fluoridated and non-fluoridated regions of Raichur District, Karnataka

BACKGROUND AND AIM: A staple food crops have varied role in diet of people living in particular regions of world; hence, it is critical to recognize their productivity. Therefore, the purpose of this study was to estimate fluoride concentration in staple food crops grown in highly fluoridated and non-fluoridated regions and its correlation with soil. METHOD: Total 36 samples were collected of which 18 samples consisting of each three samples of rice, redgram and jowar were selected. Likewise 18 corresponding soil samples from both areas were collected. All samples were ashed for 4–6 hours at 550°C in muffle furnace. The samples were allowed to cool, after which 10 ml distilled water was added to each sample and fluoride concentration was determined using ion selective electrode method, before each sample analysis the instrument was standardized using fluoride containing TISAB (III) buffer solution. The data was tabulated and subjected to cross-sectional observational statistical analysis using SPSS software applying unpaired t-test and Pearson’s test. RESULT: The mean fluoride concentration in crops and soils were rice (0.79 ppm), redgram (4.26 ppm), jowar (8.8 ppm) and in soil of rice (1.23 ppm), redgram (1.23 ppm) and jowar (1.21 ppm) respectively in fluoridated area. Where as in non-fluoridated area rice (0.07 ppm), redgram (0.81 ppm), jowar (0.81 ppm) and in soil of rice (0.61 ppm), redgram (0.07 ppm) and jowar (0.52 ppm) respectively. The resultant correlation between staple food crops with their corresponding soils were found highly significant in both regions with P value <0.005; hence, crops in fluoridated region exhibited increased fluoride retention, whereas crops in non-fluoridated region had optimal fluoride levels. CONCLUSION: Fluoride concentration in food crops has strong correlation with their respective soils and water irrigation properties.