# Risk Assessment of Metals in Black Fungus and Culture Substrates Based on Monte Carlo Simulation
## 3 Results
### Comparative Analysis of Simulated Distribution of Heavy Metal Content in Black Fungus
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Sample Category**} & \multirow{2}{*}{**Element**} & **Average** & **Minimum** & **Maximum** & **Median** & **Limit** & **Samples of** & **Exceeded the** & **Excess Ratio** \\  & & **Content** & **Value** & **Value** & **(mg/kg)** & **(mg/kg)** & **(mg/kg)** & **Standard/Total** & **Sample** \\ \hline \multirow{4}{*}{Black fungus} & As & 0.177 \(\pm\) 0.143 & 0.007 & 0.966 & 0.143 & 0.5 & 3/179 & 1.68 \\  & Pb & 0.315 \(\pm\) 0.233 & 0.018 & 1.300 & 0.233 & 1.0 & 1/179 & 0.59 \\  & Cd & 0.097 \(\pm\) 0.082 & 0.003 & 0.511 & 0.082 & 0.5 & 1/179 & 0.59 \\  & Cr & 1.689 \(\pm\) 1.426 & 0.056 & 5.602 & 1.426 & 1.0 & 68/179 & 37.99 \\ \hline \multirow{4}{*}{Market black fungus} & As & 0.261 \(\pm\) 0.199 & 0.052 & 0.966 & 0.200 & 0.5 & 3/36 & 8.33 \\  & Pb & 0.340 \(\pm\) 0.198 & 0.018 & 0.968 & 0.294 & 1.0 & 0/36 & 0 \\  & Cd & 0.079 \(\pm\) 0.047 & 0.020 & 0.287 & 0.066 & 0.5 & 0/36 & 0 \\  & Cr & 3.187 \(\pm\) 1.697 & 0.056 & 5.602 & 3.484 & 1.0 & 12/36 & 33.33 \\ \hline \multirow{4}{*}{Base black fungus} & As & 0.146 \(\pm\) 0.104 & 0.007 & 0.481 & 0.129 & 0.5 & 0/143 & 0 \\  & Pb & 0.309 \(\pm\) 0.243 & 0.030 & 1.300 & 0.243 & 1.0 & 1/143 & 0.69 \\ \cline{1-1}  & Cd & 0.102 \(\pm\) 0.071 & 0.003 & 0.511 & 0.071 & 0.5 & 1/143 & 0.69 \\ \cline{1-1}  & Cr & 1.509 \(\pm\) 1.042 & 0.094 & 5.308 & 1.042 & 1.0 & 56/143 & 39.16 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Concentrations of heavy metal residues in different black fungi. Figure 1: Residual arsenic (**A**), plumbum (**B**), cadmium (**C**) and chromium (**D**) in dried black fungus based on Monte Carlo simulation. Figure 1C shows that the MRL value of Cd in black fungus after simulation is 4.42 mg\(\cdot\)kg\({}^{-1}\), the minimum value is 0 mg/kg, the average residual amount is 0.097 mg\(\cdot\)kg\({}^{-1}\), and the 90% confidence interval is mainly distributed in the range of 0.019-0.236 mg\(\cdot\)kg\({}^{-1}\). The maximum residual amount of Cd in the base sample was 3.508 mg\(\cdot\)kg\({}^{-1}\), the minimum value was 0 mg\(\cdot\)kg\({}^{-1}\), the average value was 0.103 mg\(\cdot\)kg\({}^{-1}\), and the 90% confidence interval was mainly distributed in the range of 0.017-0.262 mg\(\cdot\)kg\({}^{-1}\). The maximum residual amount of Cd in the market sample was 0.347 mg\(\cdot\)kg\({}^{-1}\), the minimum value was 0 mg\(\cdot\)kg\({}^{-1}\), and the average value was 0.077 mg\(\cdot\)kg\({}^{-1}\). The 90% confidence interval was mainly distributed in the range of 0.028-0.147 mg\(\cdot\)kg\({}^{-1}\). The residual amount of Cd in black fungus collected in the market is relatively lower than that in the base, and the probability of extreme value is relatively high, but the results show that the difference between the sampling links is not significant, that is, the sampling link has no significant impact on the heavy metal Cd content. Figure 1D shows that the MRL value of Cr in black fungus after simulation is 12.188 mg\(\cdot\)kg\({}^{-1}\), the minimum value is 0 mg\(\cdot\)kg\({}^{-1}\), the average residue is 1.137 mg\(\cdot\)kg\({}^{-1}\), and the 90% confidence interval is mainly distributed in the range of 0.06-3.41 mg\(\cdot\)kg\({}^{-1}\). The maximum residual amount of Cr in the base sample was 13.617 mg\(\cdot\)kg\({}^{-1}\), the minimum value was 0 mg\(\cdot\)kg\({}^{-1}\), and the average value was 1.133 mg\(\cdot\)kg\({}^{-1}\). The 90% confidence interval was mainly distributed in the range of 0.06-3.40 mg\(\cdot\)kg\({}^{-1}\). The maximum residual amount of Cr in the market sample was 10.944 mg\(\cdot\)kg\({}^{-1}\), the minimum value was 0 mg\(\cdot\)kg\({}^{-1}\), the average value was 1.122 mg\(\cdot\)kg\({}^{-1}\), and the 90% confidence interval was mainly distributed in the range of 0.03-3.41 mg\(\cdot\)kg\({}^{-1}\).