# Fluoride Risk Assessment from Consumption of Different Foods Commercialized in a European Region
## 3 Results and Discussion  
### Fluoride Levels in the Different Food Groups Analyzed  
Table 2 shows the mean concentrations, standard deviations, and maximum and minimum values of the analyzed samples.  
Walnuts were the food group in which the highest concentrations of fluoride were registered among all the groups studied. Almonds (3.70 \(\pm\) 0.96 mg/kg) and walnuts (3.53 \(\pm\) 0.62 mg/kg) registered the highest mean levels of fluoride. The highest concentration recorded in these foods may be due to the concentration of elements that occurs after desiccating tree nuts [27]. The New Zealand Total Diet Study (NZTDS), carried out in 2016 by the Ministry for Primary Industries (MPI), registered an average concentration of fluoride in almonds of 5.66 mg/kg, higher than that found in this study [28; 29]. The differences in the origin of the sample have a considerable influence on the level of fluoride registered in the walnuts.  
The studied cereals and derivatives presented the following descending concentration sequence: bread \(>\) rice \(>\) gofio \(>\) corn. The level of fluoride registered in bread (2.54 \(\pm\) 0.85 mg/kg) and rice (2.28 \(\pm\) 0.93 mg/kg) stood out considerably. Levels found by [PERSON] et al. [10] in baked goods and cereals were between 0.04 and 1.85 mg/kg, lower than those registered in the present study. [PERSON] et al. [30], in rice cultivated in two regions in western India, registered concentrations of 0.56 \(\pm\) 0.14 mg/kg (Bankura) and 0.83 \(\pm\) 0.19 mg/kg (Purulia); in both cases, these values are lower than those registered in the present study. [PERSON] et al. [31] recorded higher levels in rice cultivated in other regions of India ranging from 6.7 \(\pm\) 0.6 to 12.0 \(\pm\) 0.9 mg/kg. The differences in the fluoride content recorded in the rice samples depend on the crop area.  
In the fruit group, fluoride was detected only in bananas, registering an average level of 1.72 \(\pm\) 0.73 mg/kg. Notably, banana is a fruit with a high percentage of water.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Group** & **Food Type** &
\begin{tabular}{c} **Concentration \(\pm\) SD** \\ **(mg/kg)** \\ \end{tabular} & **Max-Min** \\ \hline \multirow{4}{*}{Cereals and derivatives} & Rice & 2.28 \(\pm\) 0.93 & 3.62–0.53 \\  & Gofio & 1.44 \(\pm\) 0.66 & 2.32–0.53 \\  & Corn & 1.10 \(\pm\) 0.91 & 3.24–0.50 \\  & Bread & 2.54 \(\pm\) 0.85 & 3.62–1.23 \\ \hline \multirow{4}{*}{Fruits} & Citrus & \multirow{2}{*}{Not detected} \\  & Apples & & \\ \cline{2-3}  & Bananas & 1.72 \(\pm\) 0.73 & 1.98–0.86 \\ \hline \multirow{2}{*}{Tree nuts} & Almonds & 3.70 \(\pm\) 0.96 & 4.80–2.32 \\  & Walnuts & 3.53 \(\pm\) 0.62 & 4.15–2.79 \\ \hline \multirow{2}{*}{Mushrooms} & Mushrooms & 1.28 \(\pm\) 0.29 & 1.59–0.86 \\ \hline \multirow{4}{*}{Vegetables} & Onions & 0.01 \(\pm\) 0.02 & 0.06–0 \\  & Lettuce & 0.08 \(\pm\) 0.05 & 0.16–0.08 \\ \cline{1-1}  & Potato & 0.99 \(\pm\) 1.90 & 3.53–0 \\ \cline{1-1}  & Tomatoes & 0.96 \(\pm\) 0.55 & 2.14–0.40 \\ \cline{1-1}  & Carrots & 0.04 \(\pm\) 0.01 & 0.04–0 \\ \hline \multirow{4}{*}{Legumes} & Bean & 1.05 \(\pm\) 1.79 & 3.86–0 \\ \cline{1-1}  & Lentils & 0.32 \(\pm\) 0.66 & 1.84–0 \\ \cline{1-1}  & Chickpeas & 0.68 \(\pm\) 1.41 & 1.36–0 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Fluoride concentration, standard deviation, and maximum and minimum values found in the analyzed samples.  
Statistical analysis revealed the existence of significant differences (\(p<0.05\)) in the fluoride content between almonds and walnuts compared with the rest of the analyzed foods. Statistical differences were found between bread and rice compared with the rest of the foods.