Effect of Copper in Soil on Bioaccumulated Copper in Earthworm.
Kye-Hoon Kim1, Youn-Seok Choi1, Ho-Jin Kim2, and Hyun-Haeng Lee2. (1) The University of Seoul, Dept.of Env. Horticulture, 90 Jeonnong-dong, Dongdaemun-gu, Seoul, 130-743, South Korea, (2) National Institute of Agricultural Science and Technology, Rural Development Administration, Seodun-dong, Kwonseon-gu, Suwon, South Korea
Copperplates have been used widely as a roof material for buildings because it is cheap, relatively resistant to corrosion, and aesthetically acceptable due to its color. But it may contaminate soil around the buildings. This study aimed at finding the effect of copperplate roof on soil contamination and determining the relationship between extraction methods of copper in soil and bioaccumulated copper in earthworm. The concentrations of copper in soil around buildings having copperplate roofs were sampled and compared. TCLP (Toxicity Characteristic Leaching Procedure, USEPA) tests were carried out on copperplates to confirm the source of copper contamination in soil samples. TCLP tests also aimed at assessing the mobility of copper in soil. Sequential extraction techniques were used to find out prominent forms of copper in soil samples. Microcosm soil tests were also performed to determine the relationship between extraction methods of copper in soil and bioaccumulated copper in earthworm. Two buildings of University of Seoul with copperplate roofs, one built in 1981 and the other built in 2001, were selected for the study. Soil samples were taken from the building premises at depths 0-20 cm, 20-40 cm, 40-60 cm, 60-80 cm, and 80-100 cm. The samples were analyzed for their physico-chemical properties. TCLP test was carried out at 30°C for the copperplates with 2 different acids. Sequential extraction technique was then used to find out priority of the chemical form of the existing copper. Earthworm cultivated in a microcosm system up to 3 months was analyzed for copper concentration. The soils used for earthworm cultivation were also analyzed for copper with microwave assisted total concentration and 0.1 N HCl extracting solution, based on standard methods of soil analysis in Korea. Correlations of bioaccumulated concentration of copper in earthworm with concentration of copper in soil extracted with microwave assisted method for total copper concentration and 0.1 N HCl were analyzed to find out the best extracting solution for indicating the bioaccumulation of copper in earthworm.