Ecotoxicological effects of exposed CCA preservative treated wood in environments
Dong-heub Lee, Dong-won Son
For the evaluation of environmental effect of CCA treated wood exposd in the field, the simulated soil pot system of the laboratory was used. The effective components of preservatives were leached and determined after artificially conditioning a soil pot of CCA treated wood with more than 500mm water, the average monthly precipitation. As the water passed through the soil, As, Cr and Cu in the soil as well as the filtrtes were analyzed, and they were measured after scrubbing the CCA treated wood in the water. In order to discover the influence of the CCA treated wood on the aquaticecosystem, Daphnia magna, Selenastrum capricornutum and Chironomus riparius were raised in leachates of CCA treated wood. The concentrations of As, Cr and Cu after 22 days of leaching were 0.12, 1.71 and 1.76mg/L, and those in scrubbed in water for 10 minutes were 0.012, 1.99 and 2,81mg/L, respectively. The concentrations of heavy metals, As, Cr and Cu, leached by water of which the volume was 10 times of CCA treated wood during 24 hours, were 0.0076, 1.46 and 5.11mg/L, respectively. These concentrations did not affect the life action of O. latipes and Chironomus riparius. The life action of 37% among D. magna slowly occurred after 48-hours of exposure to leachates. The LC50 on S. capricornutum was reduced to 86% of heavy metal concentrations in which were washed by 10 times the volume of water of the CCA treated wood.