## 3 Results
### Health Risk Assessment
#### 3.4.1 Non-Carcinogenic Risk  
Because of the RfD values of As and Pb for air inhalation were missing (refer to Table 15), only two exposure pathways (hand-to-mouth ingestion, and dermal absorption) of As and Pb were taken into consideration for the no-carcinogenic risk assessment.  
The results in Figure 3 show that: (1) the mean non-carcinogenic hazard indices of hand-to-mouth ingestion, dermal absorption and air inhalation for male workers were \(1.08\times 10^{-1}\), \(1.02\times 10^{-6}\) and \(3.72\times 10^{-4}\), respectively; (2) the mean non-carcinogenic hazard indices of hand-to-mouth ingestion, dermal absorption and air inhalation for female workers were \(1.27\times 10^{-1}\), \(1.07\times 10^{-6}\) and \(4.36\times 10^{-4}\), respectively; (3) the mean total exposure hazard indices for male and female workers were \(1.09\times 10^{-1}\) and \(1.28\times 10^{-1}\), respectively. The hazard indices distribution of different exposure pathways indicated that the non-carcinogenic hazard indices of hand-to-mouth ingestion, dermal absorption and air inhalation for male and female workers were distributed in the range of \(10^{-2}\)\(\sim\)\(10^{-1}\), \(10^{-8}\)\(\sim\)\(10^{-6}\), and \(10^{-5}\)\(\sim\)\(10^{-3}\), respectively. The hazard indices of hand-to-mouth ingestion were 5-6, and 2-3 orders of magnitude higher than that of dermal absorption and air inhalation, respectively.  
The results in Figure 4 show that: (1) the average non-carcinogenic hazard indices of As, Cd, Hg, Cr and Pb for male workers were \(8.04\times 10^{-3}\), \(1.32\times 10^{-2}\), \(1.52\times 10^{-3}\), \(5.75\times 10^{-2}\) and \(2.84\times 10^{-2}\), respectively; (2) the average non-carcinogenic hazard indices of As, Cd, Hg, Cr and Pb for female workers were \(9.43\times 10^{-3}\), \(1.55\times 10^{-2}\), \(1.78\times 10^{-3}\), \(6.75\times 10^{-2}\) and \(3.34\times 10^{-2}\), respectively. The hazard indices distribution of different heavy metals suggested that the non-carcinogenic hazard indices of As, Cd, Hg, Cr and Pb for male and female workers were distributed in the range of \(10^{-4}\)\(\sim\)\(10^{-2}\), \(10^{-4}\)\(\sim\)\(10^{-2}\), \(10^{-5}\)\(\sim\)\(10^{-3}\), \(10^{-3}\)\(\sim\)\(10^{-1}\), and \(10^{-4}\)\(\sim\)\(10^{-2}\), respectively. Therefore, Cr contributed the most to the non-carcinogenic hazard for male and female workers, following by As, Cd, Pb and Hg.  
\begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Elements**} & \multicolumn{2}{c}{**Principal Component**} \\ \cline{2-3}  & **F1** & **F2** \\ \hline As & \(-0.84\) & \(0.49\) \\ Cd & \(0.02\) & \(0.99\) \\ Hg & \(0.98\) & \(0.01\) \\ Cr & \(0.98\) & \(-0.08\) \\ Pb & \(0.96\) & \(0.13\) \\ \hline \hline \end{tabular} Notes: Extraction method: Principal components analysis; Rotation method: Varimax with Kaiser normalization; Rotation converged in 10 iterations.  
\end{table}
Table 3: Factor loading matrix after orthogonal rotation of maximum variance.  
Figure 3: Distribution of non-carcinogenic risks posed through different exposure pathways.  
Figure 4: Distribution of non-carcinogenic risks posed by different heavy metals.