Ecological risk assessment of heavy metals in sediment from Klong Luang Reservoir,
Chonburi, Thailand

Heavy metals (HMs) in the aquatic system are a global problem and environmental hazard. Sediment is widely recognized as the repository and sink pollutants of HMs. The increasing concentration of HMs in the Khlong Luang reservoir can be attributed to natural origin and anthropogenic, including discharge from various urbanization, industrialization, direct and indirect discharges from open dumping, vehicle emissions, agriculture, and road runoff can release HMs to the reservoir. The potential harm posed by HMs has emerged as a significant concern for human health and ecological risk. HMs, including arsenic (As), nickel (Ni), zinc (Zn), manganese (Mn), lead (Pb), and copper (Cu) were quantified in the sediment by using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) technique. As a result, Mn had the highest concentration of 349.81 mg/kg. Data monitoring geo-accumulate index (Igeo) of As found in heavily contaminated (3.70). The Contamination factor (CF) of As, Pb, Zn, and Cu are in a high degree of contamination (CF≥6). Modified contamination degree (mCd) and potential ecological risk (PER) indicate Khlong Luang reservoir is in high-risk condition (8200). The reservoir status is at a very high ecological risk considering environmental quality. Hence, it is imperative to monitor pollution in the future.