HEAVY METAL CONTAMINATION AND ECOLOGICAL RISK ASSESSMENT OF PHU HIN RONG KLA NATIONAL PARK

Abstract

The balance of ecosystems depends on soil sustainability, with heavy metal concentrations being a key factor determining the level of contamination and soil degradation. This study aimed to assess the contamination levels of heavy metals, including copper (Cu), zinc (Zn), cadmium (Cd), lead (Pb), and chromium (Cr), accumulated in the soil of Phu Hin Rong Kla National Park, Phitsanulok Province, Thailand. Additionally, the study evaluated the ecological risk using the Ecological Risk Index (ER) for individual metals and the Potential Ecological Risk Index (PERI) for overall contamination levels. The results indicated that in the nature trail area, the concentrations of Cd, Cr, Cu, Pb, and Zn ranged from 0.02–0.25, 3.23–6.18, 1.75–7.84, 1.15–9.21, and 10.19–19.89 mg/kg, respectively. In contrast, in the accommodation and parking area, the concentrations of Cd, Cr, Cu, Pb, and Zn ranged from 0.03–0.08, 12.56–29.07, 5.23–10.48, 5.17–7.90, and 23.56–30.49 mg/kg, respectively. The heavy metal concentrations in the studied areas did not exceed the soil quality standards of the National Environmental Board of Thailand. The ecological risk assessment revealed that the ecological risk indices for all samples were at a low level, indicating minimal contamination risk in the study area. Although the findings suggest that the soils in the national park are not contaminated with heavy metals at hazardous levels, there are indications of anthropogenic influences. Therefore, continuous soil quality monitoring is essential to prevent ecosystem degradation and ensure long-term environmental sustainability.