Rate Uptake of Three Common Pharmaceuticals in Celery, Apium Graveolens

Abstract

Recent droughts in the southwestern United States have heightened the interest in using more reclaimed water for agricultural irrigation. Treated wastewater effluent is a source of irrigation water and contains many pharmaceutical microcontaminants. Currently, there is little knowledge on if these microconstituents will enter food crops and if so where they will be found within the plant. For this experiment, the uptake of 17α-ethynylestradiol, fluoxetine HCl (Prozac®), and ibuprofen within different sections of a celery stalk over a 24-h time period was examined. Results found that all of these pharmaceuticals were taken up into the celery stalks within 24 h. Ibuprofen was found to have reached concentrations of 1 μg/g within the leaves in just 1 h. Metabolites of the ibuprofen were also detected at all locations within the stalk for all time periods. The concentration of EE2 in the submerged section of the stalk was found to increase from 0.031 to 0.911 μg/g of celery in just 23 h. The EE2 began to rise higher within the stalk to reach a concentration of 8.94 ng/g about 6 in above the base after 24 h. Fluoxetine HCl concentrations rose to 0.832 μg/g of celery within the submerged section of the stalk during the 24 h. After 12 h, fluoxetine HCl was detected within the bottom 4 in of the stalk. EE2, fluoxetine HCl, and ibuprofen all exhibit potential for uptake within food crops. Further studies on additional food crops and pharmaceuticals would be required to assess the full risk posed to human eating food crops irrigated with treated wastewater effluent.