Distribution and concentrations of pharmaceutical and personal care products (PPCPs) within cattails (Typha latifolia) as function of exposure time.

DOUCETTE, WILLIAM; MENONE, MIRTA LUJÁN; PÉREZ, DÉBORA JESABEL

TORONTO

Congreso; SETAC North America 40th Annual Meeting; 2019

Society of Environmental Toxicology and Chemistry

The passive uptake of organic contaminants such as PPCP by plants iswell documented. Uptake is often quantified and reported as concentration ratios between whole plants or specific plant compartments (e.g.roots, shoots, leaves, fruit) and the exposure media (e.g. soil, air water).The ratios may also be normalized to the amount water transpired bythe plant or to lipid content of the plant tissue. However, there have beenrelatively few studies that have investigated the changes in concentrations among the various plant tissue compartments over time. Usinghydroponically grown cattails (Typha latifolia)exposed to four PPCPs(carbamazepine, fluoxetine, gemfibrozil, trichlosan) at environmentallyrelevant concentrations near 20 µg/L, the uptake and distribution of thesecompounds within the plants were evaluated at several time periodsover a 42 day growing period. Thirty-six plants of uniform size wereselected, eighteen exposed to the target PPCPs and eighteen untreated.Two unplanted, unexposed controls were also used. A nutrient solutioncontaining the target compounds was used to replenish water lost totranspiration and maintain a consistent exposure environment (semistatic exposure bioassay). Root zone samples were collected over timeto determine the average exposure concentration. Whole plants wereharvested at days 7, 14, 21, 28, 35 and 42 days. Concentrations of PPCPsin the exposure solution and various plant tissues were determined bydirect injection LC-MSMS or after extraction, concentration and cleanup.Carbamazepine, fluoxetine, gemfibrozil and triclosan were detected in allunderwater tissues (roots, rhizome, etc.) and above water tissues, exceptgemfibrozil which was not detected in shoots. Carbamazepine concentrations were highest in the upper leaves in the plants exposed for the longest time. Concentrations in the below water tissues were 30-40 times lowerthan the upper leaves and did not vary significantly with time. Abovewater tissue concentrations for fluoxetine were highest in the lower leavesand similar to the concentrations in the below water tissues. Triclosanconcentrations were greatest in the roots and were about 50 higher thanthose found in the leaves. Overall, the results show that the root uptake,translocation and distribution within the plant tissues varies with thephysical chemical properties of PPCP and longer exposures result inhigher leaf concentrations for those compounds that are translocated fromroot to shoot. For compounds that are readily translocated from roots toshoots, the large differences in tissue concentrations could have importantimplications in risk assessment and biomonitoring applications.