Abstract
This research focuses on the heavy metal contamination of the paddy soils and rice from Kocˇani Field (eastern Macedonia) resulting from irrigation by riverine water impacted by past and present base-metal mining activities and acid mine drainage. Very high concentrations of As, Cd, Cu, Pb and Zn were found in the paddy soils (47.6, 6.4, 99, 983 and 1,245 lg g-1 ) and the rice (0.53, 0.31, 5.8, 0.5 and 67 lg g-1 ) in the western part of Kocˇani Field, close to the Zletovska River, which drains the mining facilities of the Pb–Zn mine in Zletovo. In terms of health risk, the observed highest concentrations of these elements in the rice could have an effect on human health and should be the subject of further investigations.
Introduction
Base-metal mining together with milling and grinding operations, concentrating ore and the disposal of tailings along with the acid mine and mill wastewater are some of the most important sources of heavy metals in the environment (Adriano 1986). Therefore, elevated concentrations of heavy metals can be found in and around abandoned and active mines due to the discharge and dispersion of mine waste materials, including tailings and acid mine drainage effluents into nearby agricultural soils, food crops, riverine water and stream sediments (Jung 2001; Korre et al. 2002; Lee et al. 2001; Liu et al. 2005; Lu and Zhang 2005; Simmons et al. 2005; Witte et al. 2004; Wong et al. 2002; Yang et al. 2004). It is well known that heavy metals in agricultural soils can influence both crop yield and quality, and soil containing various elements is a primary nutrient medium for plants. Food crops grown in contaminated areas may accumulate much higher than normal amounts of heavy metals, which may pose a significant public health risk to the local community.