Uptake of the pharmaceutical Fluoxetine Hydrochloride from growth medium by Brassicaceae

Since the European Union banned disposal of sewage sludge (SS) at sea in 1998 the application rate of SS to land has risen significantly. Land application is thus possibly an important transport route for SS-associated organic chemicals, including pharmaceuticals, to soils and perhaps also to plants. The potential for the selective serotonin re-uptake inhibitor, Fluoxetine HCl, to undergo uptake into Brassicaceae tissues was therefore investigated in a tissue culture study under laboratory conditions for 12 weeks. From growth medium containing 280 ng Fluoxetine HCl mL(-1), translocation into Brassica oleracea var. botrytis (cauliflower) stems (5% mean uptake of applied burden; 0.49 microg g wet weight(-1)) and leaves (3% mean uptake; 0.26 microg g wet weight(-1)) was confirmed, but no evidence of uptake into the curd was found; other possible explanations of the observations are also discussed. Although the data for individual plants were highly variable, as was the recovery of spiked internal standard (deuterated Fluoxetine HCl), the results nonetheless suggest uptake of Fluoxetine may indeed be a potential transport route to plants. A similar study of uptake from soils rather than from an artificial medium should now be undertaken, with greater numbers of replicates and improved analytical methods. Such studies have already demonstrated uptake of some antibiotics from manured soils by a variety of plants including Brassicaceae, suggesting that the uptake mechanisms may be more general.