# Weekly and Longitudinal Element Variability in Hair Samples of Subjects Non-Occupationally Exposed
## 3 Results and Discussion
### Comparison with Studies on Adult and Teenager Population  
Table 4 shows a comparison between these data and similar levels found in a previous study performed in Rome [50]. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multirow{2}{*}{**Our Data**} & \multicolumn{6}{c}{**Literature Values**} \\ \cline{3-8}  & & \multicolumn{3}{c}{**Rome [50]**} & \multicolumn{3}{c}{**Italy [67]**} & **International [68; 69; 70; 71; 72; 73; 74; 75; 76]**} \\ \cline{3-8}  & & **Female** & **Male + Female** & **Light Brown** & & \\ \hline Ag & 0.740 \(\pm\) 0.271 & 0.23 \(\pm\) 0.42 & 0.40 \(\pm\) 1.58 & 0.29 \(\pm\) 0.30 & 0.83 \(\pm\) 1.96 & 0.005–9.9 \\ Au & 0.022 \(\pm\) 0.014 & 0.06 \(\pm\) 0.08 & 0.09 \(\pm\) 0.16 & 0.10 \(\pm\) 0.12 & 0.036 \(\pm\) 0.038 & 0.0005–591 \\ Ba & 1.44 \(\pm\) 0.23 & 0.33 \(\pm\) 0.94 & 0.57 \(\pm\) 1.50 & 0.87 \(\pm\) 1.96 & & 0.12–29 \\ Br & 26.5 \(\pm\) 3.5 & 9.63 \(\pm\) 15.2 & 8.66 \(\pm\) 13.8 & 5.54 \(\pm\) 4.92 & 12.9 \(\pm\) 10.1 & 0.15–490 \\ Ca & 2010 \(\pm\) 512 & 812 \(\pm\) 580 & 1120 \(\pm\) 1060 & 1776 \(\pm\) 1776 & 750 \(\pm\) 1150 & 7–10887 \\ Co & 0.041 \(\pm\) 0.013 & 0.17 \(\pm\) 0.26 & 0.17 \(\pm\) 0.25 & 0.12 \(\pm\) 0.17 & 0.145 \(\pm\) 0.133 & 0.002–15 \\ Cr & 0.086 \(\pm\) 0.057 & 0.15 \(\pm\) 0.10 & 0.17 \(\pm\) 0.15 & 0.17 \(\pm\) 0.09 & 0.234 \(\pm\) 0.155 & 0.026–65.3 \\ Cu & 15.1 \(\pm\) 10.4 & 9.56 \(\pm\) 4.78 & 10.5 \(\pm\) 7.11 & 11.6 \(\pm\) 8.91 & & 3.68–72.5 \\ Eu & 0.001 & & & & & - \\ Fe & 17.7 \(\pm\) 5.9 & 16.8 \(\pm\) 26.4 & 16.5 \(\pm\) 23.9 & 17.5 \(\pm\) 19.3 & 13.5 \(\pm\) 6.2 & 3–2400 \\ K & 249 \(\pm\) 66 & 335 \(\pm\) 272 & 314 \(\pm\) 274 & 258 \(\pm\) 280 & 940 \(\pm\) 1110 & 0.94–2370 \\ La & 0.957 \(\pm\) 0.592 & 0.03 \(\pm\) 0.04 & 0.03 \(\pm\) 0.03 & 0.03 \(\pm\) 0.03 & 0.038 \(\pm\) 0.031 & \(<\)0.003–37 \\ Mn & 3.75 \(\pm\) 1.24 & 0.40 \(\pm\) 0.33 & 0.42 \(\pm\) 0.32 & 0.41 \(\pm\) 0.24 & & 0.03–81.5 \\ Na & 109 \(\pm\) 18 & 647 \(\pm\) 545 & 581 \(\pm\) 521 & 476 \(\pm\) 426 & 1180 \(\pm\) 1260 & 0.04–3500 \\ Rb & 0.269 \(\pm\) 0.164 & & & & 3.20 \(\pm\) 5.06 & 0.01–0.14 \\ Sb & 0.075 \(\pm\) 0.028 & 0.06 \(\pm\) 0.06 & 0.06 \(\pm\) 0.05 & 0.07 \(\pm\) 0.05 & 0.047 \(\pm\) 0.034 & 0.007–38 \\ Sc & 0.007 \(\pm\) 0.005 & 0.0010 \(\pm\) 0.0003 & 0.0010 \(\pm\) 0.0002 & 0.0011 \(\pm\) 0.0008 & 0.0023 \(\pm\) 0.0025 & 0.004–550 \\ Se & 0.413 \(\pm\) 0.055 & 0.96 \(\pm\) 1.55 & 0.99 \(\pm\) 1.56 & 1.17 \(\pm\) 1.62 & 0.64 \(\pm\) 0.28 & 0.002–666 \\ Tb & 0.020 & & & & & - \\ Th & 0.009 \(\pm\) 0.018 & & & & 0.0011 \(\pm\) 0.0014 & - \\ W & 0.019 \(\pm\) 0.012 & & & & & - \\ Zn & 52.3 \(\pm\) 19.5 & 178 \(\pm\) 46 & 189 \(\pm\) 82 & 240 \(\pm\) 144 & 139.9 \(\pm\) 65.1 & \(<\)1–1770 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Concentration (\(\mu\)g g\({}^{-1}\)) comparison between these data and those found in other Italian and international studies. First, the presence of elements such as Ag, Au, and Co can be due to cosmetics and/or personal hygiene products. In particular, Ag shows concentrations comparable with the data of the Rome group (0.740 \(\pm\) 0.271 ug g\({}^{-1}\) versus 0.40 \(\pm\) 1.58 ug g\({}^{-1}\)) [50] and the Italian population (0.83 \(\pm\) 1.96 ug g\({}^{-1}\)) [67] as well as Au (0.022 \(\pm\) 0.014 ug g\({}^{-1}\) vs. 0.036 \(\pm\) 0.038 ug g\({}^{-1}\) for the Italian population) [50], whereas Co shows decidedly lower levels than the Italian population (0.041 \(\pm\) 0.013 ug g\({}^{-1}\) vs. 0.145 \(\pm\) 0.133 ug g\({}^{-1}\)), but they fall within the international data (0.002-15 ug g\({}^{-1}\)) [68; 69; 70; 71; 72; 73; 74; 75; 76]. Levels of Ca, K, and Na are in line with the data of the Rome and Italy groups. In particular, Ca and K show similar levels to the light brown hair in the Rome group [50] (Ca: 2010 \(\pm\) 512 ug g\({}^{-1}\) vs. 1776 \(\pm\) 1776 ug g\({}^{-1}\); K: 249 \(\pm\) 66 ug g\({}^{-1}\) vs. 258 \(\pm\) 280 ug g\({}^{-1}\)) with a much lower standard deviation.