THE UPTAKE OF TRACE ELEMENTS IN LAB-CONTAMINATED SOILS FROM LEBANON, CT

Lebanon is a predominantly agricultural town, located in Connecticut, northeastern USA. In the last few years, special attention has been given to trace elements enrichment within agricultural soils which are often attributed to both geogenic and anthropogenic sources. The mobility and bioavailability of these elements has led to concerns on the increasing risk for plant uptake, and possible impact on human health. This project examined the soil to plant (swiss lettuce) transfer rate of arsenic (As), copper(Cu), and zinc(Zn) in laboratory contaminated soils from Lebanon, CT with the goals of determining: i) effect of elevated concentration of trace elements on the growth of lettuce plant, ii) the impact of soil constituent on the bioavailability of As, Cu and Zn in Lebanon soil for plant uptake, iii) the transfer ratio of As, Cu and Zn from soil to lettuce plant, and overall quality of vegetable grown on contaminated soils for human consumption. To address this, soil samples were collected from four different locations in Lebanon, CT and analyzed for particle size distributions, organic matter contents, and trace elements contents. Three soil samples were later spiked with solution containing 15 ppm concentration of As, Cu and Zn, while the fourth sample was used as a control. Each sample was planted with one packet of swiss chard lettuce seeds in a temperature controlled greenhouse, and irrigated with 50 ml of water twice a week. Results showed spatial variability in the bioavailability of trace elements due to variation in the abundance of clay and organic matter contents. Using statistical analysis, we examined the transfer ratio and the overall quality of lettuce grown on laboratory contaminated agricultural soils.