# Heavy Metals in Urban Street Dust: Health Risk Assessment (Lublin City, E Poland)
## 3 Results
In 2013, most values were contained in the 0.00048-0.0037 interval, but a small peak for large values (i.e., above 0.015) was visible. In 2018, most values were in the 0.001-0.0039 interval, and sites with high HI values did not appear. In 2013, the distribution for Ni was more flattened, with most HI values within the 0.00019-0.000366 interval, and in 2018 the distribution was more elongated, with most HI values in the lower 0.00011-0.000256 interval. At the same time, the kurtosis of the distribution in 2013 was similar to the kurtosis of normal distribution, but the distribution for Ni was left-skewed (i.e., had a surplus of data with high values), while that in 2018 was right-skewed and elongated. This means that most data were contained in the narrower interval with lower values. In the case of the HI for Pb, the kurtosis of distribution in 2013 was significantly higher, while in 2018 it was slightly higher than the kurtosis of normal distribution. The modal interval shifted to lower values in 2018. Most of the data were between 0.011-0.02 in 2013 and between 0.0036-0.09 in 2018. At the same time, there were no high (0.04-0.05) HI values for Pb in 2018. For Zn, both distributions were slightly elongated and statistically symmetrical. However, the distribution for 2018 was more elongated (more compact). In 2013, most of the data were between 0.00055 and 0.00155, and in 2018 between 0.0003 and 0.00138. The HI distribution for the three elements--Cu, Cd and Pb--shows a clear change between 2013 and 2018. There was an absence of the highest values (extremely high compared to the other values) deviating from the modal values. Figure 2: Distribution of HI data for Cd (**A**), Cr (**B**), Cu (**C**), Ni (**D**), Pb (**E**), and Zn (**F**). The direction of the arrow shows the direction of the change from 2013 to 2018. Analysis of the spatial variation of HI and CR values for the individual metals shows clear changes (Figures 3 and 4). In 2013, HI reached the highest values for Cd in the south-western part of Lublin. In 2018, there was a very distinct decrease of this index in the entire area of the city. The lowest values occurred in the northern and SE part of the city. In the case of Cr, there was a mosaic-like pattern of areas with different HI values, and the spatial variation was distinctly greater in 2018. In 2013, there was an area with higher values of the index for Cu in the SW part of Lublin, but the same was not observed in 2018. The indices for Ni in 2013 were the highest in the western and eastern part of the city. In 2018, slightly higher values were found in just a few locations. In the case of Pb in 2  
In 2013, the highest CR values for adults in the case of Cd occurred in the southern, western and central part of the city (Figure 4). In 2018, areas with slightly higher values of the index were found only in the SW part, but these values were clearly lower than in 2013. CR values for cadmium exceeding the stricter limit of \(10^{-6}\) encompassed the entire area of the city in 2013 and 2018 alike. However, these values did not exceed the limit of \(10^{-4}\) in any location. CR distribution for Cr in 2013 showed slightly higher values in the western part of the city. In 2018, the distribution was entirely different--there were a few locations with clearly higher values of the index, mainly in the central part of the city. The maximum CR values for Cr, marked with red, are of the order of \(3\times 10^{-5}\). In the case of Ni, the highest CR values were recorded in 2013 in the western part of Lublin, while in 2018 nearly all of these anomalies disappeared. The maximum CR values for Ni were of the order of \(10^{-6}\). For Pb, the highest values in 2013 occurred in the eastern and south-western part of the city. Similarly to Ni, the situation in 2018 changed and CR reached clearly lower values all over the city (Figure 4). Despite the variation, CR values for Pb did not exceed the limit of \(10^{-6}\) anywhere in Lublin.