Assessment of pollution levels and ecological potential risk of the soil influenced by landfilling in a Vietnamese Mekong Delta province

The study was conducted to assess the impacts of Cai Dau and An Cu landfills in An Giang province, Vietnam on soil quality using relative soil quality index (RSQI), potential ecological risk index (PERI), and multivariable statistical methods and associated health risks. Forty-eight soil samples were collected in two layers: A (0–20 cm) and B (60–80 cm) and analyzed for five physiochemical soil parameters and eight heavy metals during the rainy and dry seasons. The results showed that pH fluctuated from weak acid to neutral, and organic matters and nutrients in soil were from poor to moderate. Heavy metal concentrations were within the Vietnamese standards. The concentrations of the soil quality parameters tended to be higher during the rainy season at the Cai Dau landfill, but lower at the An Cu landfill. The RSQI was rated as bad to good and hazardous to bad at the Cai Dau and An Cu landfills, respectively. The principal component analysis (PCA) and absolute principal component score-multiple linear regression analysis demonstrated the contribution of landfill and agricultural impacts to soil quality variability, accounting for 81.38–90.64 %. Landfills contributed greater 35 % and 50 % to heavy metal contents at Cai Dau and An Cu, respectively. The heavy metal accumulation at Cai Dau landfill was in the decreasing order of Ni > Cr > As, but that was not found at An Cu landfill. The pollution load index (PLI) indicated medium and low risks of heavy metal contamination at the Cai Dau and An Cu landfills, respectively, thus posing low potential ecological risk. The non-cancer and cancer risks of heavy metals-contaminated soil were at acceptable level. Monitoring of heavy metals in the environments surrounding landfills is needed due to its accumulative characteristics. [Display omitted] •Heavy metal concentrations are within the Vietnamese standard for agricultural land.•The RSQI was rated as bad to good at the Cai Dau landfill and hazardous to bad at the An Cu landfill.•Ni, Cr and As were likely to accumulate in the soil around the Cai Dau landfill.•Landfill and agriculture operations were the two main sources of pollution through PCA and APCS-MLR analysis.•The potential ecological and health risks to the landfills were classified as low and accepted acceptable risk, respectively.