Perchlorate Uptake in Spinach As Related to Perchlorate, Nitrate, And Chloride Concentrations in Irrigation Water

Several studies have reported on the detection of perchlorate (ClO4–) in edible leafy vegetables irrigated with Colorado River water. However, there is no information on spinach as related to ClO4– in irrigation water nor on the effect of other anions on ClO4– uptake. A greenhouse ClO4– uptake experiment using spinach was conducted to investigate the impact of presence of chloride (Cl–) and nitrate (NO3–) on ClO4– uptake under controlled conditions. We examined three concentrations of ClO4–, 40, 220, and 400 nmolc/L (nanomoles of charge per liter of solution), three concentrations of Cl–, 2.5, 13.75, and 25 mmolc/L, and NO3– at 2, 11, and 20 mmolc/L. The results revealed that ClO4– was taken up the most when NO3– and Cl– were lowest in concentration in irrigation water. More ClO4– was detected in spinach leaves than that in the root tissue. Relative to lettuces, spinach accumulated more ClO4– in the plant tissue. Perchlorate was accumulated in spinach leaves more than reported for outer leaves of lettuce ...