Figure 4
Panel (a) element-specific Eri (Cd/Cr/Ni/Pb), panel (b) aggregate RI (stacked). The figure consists of two vertical bar graphs with error bars that indicate variability in the measurements. The first graph to the left is labeled “a)”. The horizontal axis consists of four vertical bars arranged from left to right. The vertical axis ranges from 0 to 40 in increments of 5 units. The legend at the bottom identifies bars for “Cadmium”, “Chromium”, “Nickel”, and “Lead”, which reflect the bars arranged from left to right across the horizontal axis. A horizontal reference line is drawn at 40. The data for the bars are as follows: Cadmium: 34.3 with an error bar ranging from about 32.6 to 36.0. Chromium: 3.2 with an error bar ranging from about 3.0 to 3.4. Nickel: 10 with an error bar ranging from about 9.7 to 10.5. Lead: 11.1 with an error bar ranging from about 10.6 to 11.6. The second graph to the right is labeled “b)” and is a vertically stacked bar graph. The horizontal axis consists of a single stacked bar. The vertical axis ranges from 0 to 70 in increments of 10 units. The legend to the right identifies the segments from top to bottom as “Cadmium”, “Chromium”, “Nickel”, and “Lead”. The data for the segments are as follows: Lead: 11.1 at the base. Nickel: 10.1 stacked above Lead. Chromium: 3.2 stacked above Nickel. Cadmium: 34.3 stacked at the top. The total height of the stacked bar is 58.7, which includes an error bar at the very top, ranging from about 55.8 to 61.6. Note: All numerical data values are approximated.Own elaboration graph comparing (a) element-specific potential ecological risk (Eri) for Cd, Cr, Ni and Pb and (b) aggregate Ecological Risk Index (RI). Toxic-response factors and class boundaries follow Rahman et al. (2014). Composite RI value as the sum of individual Eri components; therefore, error bars are displayed only for the constituent Eri values in panel (a) and not for the aggregated RI in panel (b). Error bars represent ± standard deviation of analytical triplicates