Predicting Perchlorate Uptake in Greenhouse Lettuce from Perchlorate, Nitrate, and Chloride Irrigation Water Concentrations

208 Perchlorate (ClO4 −) has been detected in edible leafy vegetables irrigated with Colorado River water. The primary concern has been the ClO4 − concentration in lettuce (Lactuca sativa L. var. capitata L.). There has been a limited number of studies on ClO4 − uptake, but the interactive effect of other anions on ClO4 − uptake is not known in detail. We conducted a greenhouse ClO4 − uptake experiment using two types of lettuce (iceberg and butterhead) to investigate the interaction of uptake of ClO4 −, Cl−, and NO3 − on ClO4 − uptake under controlled conditions. We examined three concentrations of ClO4 −, 40, 220, and 400 nmolc/L; Cl − at 2.5, 13.75, and 25 mmolc/L; and NO3 − at 2, 11, and 20 mmolc/L. Perchlorate was taken up the most in lettuce when ClO4 − was the greatest and NO3 −