Heavy Metal Concentration and Risk Assessment of Soil and Rice in and around an Open Dumpsite in Thailand

This study aimed to determine the heavy metal concentration in the soil and rice in and around Nakhonluang district open dumpsite in Phra Nakhon Si Ayutthaya province of Thailand and to assess the human health risk of these metals. The soil samples demonstrated heavy metal concentrations in the following order: Fe > Mn >Zn > Cu > Cr > Ni > Pb (Cd was not detected), and the average concentrations of each metal in soil from the dumpsite area were higher than those in the surrounding area. The average concentrations of Mn in the soils exceeded the screening level for higher plant protection of the USEPA’s Eco-SSL while the average Zn and Cu concentrations in the soil samples from the dumpsite exceeded the level for good soil and safety to life recommended by LDD. The rice exhibited metal concentrations in the following order: root > straw > grain. A carcinogenic human health risk assessment (RTotal) indicated that the values from the soil samples and the rice were at safe levels. The sum of noncarcinogenic hazard values (Cr, Cu, Mn, Ni, Pb, and Zn) indicated that exposure to the soils around the dumpsite area may pose adverse health effects (HI < 1) while exposure to the soils in the dumpsite area carries a high risk of causing adverse health effects both in children (HI = 10.5) and adults (HI = 2.18). It is suggested that suitable management measures should be applied to prevent or reduce heavy metal contamination in and around the dumpsite area.