# Risk Elements in Total Suspended Particles in Areas Affected by Opencast Mining of Brown Coal
## 3 Results and Discussion
### Human Health Risks of the TSP-Associated Risk Elements  
Table 2 shows the results of the average daily doses (ADD) for oral uptake of risk elements contained in the deposited TSP. For adult estimation, levels exceeding \(10^{-4}\), indicating a potential health risk, were recorded only for the essential elements, i.e., Cu, Mn, and Zn. For children, however, values exceeding the \(10^{-4}\) level were also calculated for As, Be, Cr, Co, Pb, and V. Therefore, it is important to identify the sources and fate of these elements in the deposited TSP. Subsequently, further research is required in order to reduce their contents in the TSP. The estimated ADD values did not significantly differ (\(p<0.05\)) among the seasons of the year for most of the investigated elements. However, chromium showed significantly higher (\(p<0.05\)) ADD values in spring and summer, compared to autumn. On the contrary, the ADD values for As, Pb, and V were significantly (\(p<0.05\)) higher in winter compared to spring, possibly related to the coal-based local heating in the winter. This trend differs from the total amounts of elements deposited with the TSP, as presented in Figures 2-11. Since the ADD values were calculated from the element  
contents in mg/kg of the deposited TSP, this implies that these elements seemed to be more concentrated in the lower portion of the deposited TSP in winter and vice versa in spring. The hazard quotient (HQ) values (Table 3) show low values, decreasing in the order Pb > As > Cd \(\approx\) Cr > Zn > Cu. Although the HQ levels did not exceed the value 1, the potential health risks of Pb and As should be taken into account, especially during the winter seasons. Moreover, in this study, only the oral intake of the elements was assessed due to missing data on essential variables that affect dermal contact (such as differences in the surface of skin exposed in the winter and summer, etc.). Therefore, the expected sum of the HQs derived from the individual exposure pathways will be even higher, posing undeniable health risks. [PERSON] et al. [59] assessed the potential human health risks of coal dust near a coal mining area in Cherat, Pakistan. They calculated health index (HI, given as the sum of oral, dermal, and inhalation ADDs) values of less than 1 for all the investigated risk elements, decreasing in the order Pb > Cr > Cd > Ni > Cu > Co > Zn. No severe cancer risks were identified in this case, but the authors assumed that continued mining could lead to unsafe limits. [PERSON] and [PERSON] [47] reported HQ values exceeding the safe dose for Cd, Cr, Cu, Pb, and As in the area of the Jharia coalfield in India. Among the investigated risk elements, [PERSON] et al. [23] highlighted Cd as the most significant element for cancer risk in the coal mining area. Similarly, [PERSON] et al. [60] showed enriched contents of Cd and Pb on the urban PM in Tianjin, China. [PERSON] et al. [61] monitored urban soil risk element contents in the city of Darkhan (Mongolia), where increased concentrations of Pb, Mo, Sb, Zn, W, Cr, As, Cd, and Cu were recorded in the industrial zone (thermal power plant, leather goods plant, and metallurgical plant), estimating a medium health risk in this area, especially for children. Therefore, although the predominant elements present in the PM differ in the individual mining and industrial areas, the conclusions derived from the obtained results are in principle comparable. Assessing the potential health effects of the TSP-associated risk elements, the potential bioaccessibility of these elements should be considered. [PERSON] et al. [62] applied the BCR sequential extraction procedure [63] to estimate the bioaccessibility of risk elements bound to TSP and PM in Nanjing, China. The bioaccessible fractions of Zn, Pb, As, and Cu in PM exceeded 60%, indicating high potential risks, whereas elements such as Cr, Ni, and Co were primarily associated with less bioaccessible PM fractions.