文摘
Medicines play an important role in the treatment and prevention of disease. Whereas the side effectson human and animal health resulting directly from treatment have been widely documented, onlyrecently have the occurrence and fate of medicines in the environment and the potential consequencesfor human health been recognized as an issue warranting consideration. Medicines have been shownto be released to soils and to persist in the environment. This study was performed to investigate thepotential for a range of veterinary medicines to be taken up from soil by plants used for humanconsumption and to assess the potential significance of this exposure route in terms of human health.Soil analyses indicated that, for selected substances, measurable residues of these are likely to occurin soils for at least 5 months following application of manure containing these compounds. Experimentalstudies on the uptake of veterinary medicines into carrot roots (tubers) and lettuce leaves showedthat only florfenicol, levamisole, and trimethoprim were taken up by lettuces, whereas diazinon,enrofloxacin, florfenicol, and trimethoprim were detected in carrot roots. Measured concentrations inplant material were used to model potential adult human exposure to these compounds. Althoughexposure concentrations were appreciable in a few instances, accounting for ~10% of the acceptabledaily intake values (ADI), all were lower than the ADI values, indicating that, at least for compoundswith properties similar to those considered here, there is little evidence of an appreciable risk. Thisexposure route may, however, be important when veterinary medicines have a very low ADI, at whichthey elicit subtle effects over prolonged periods, or when exposure is occurring via a number of routesat once. Although degradation products (produced in the soil or the plant) were not measured, it ispossible for some substances that these could increase the risks to consumers.Keywords: Pharmaceuticals; veterinary; plant uptake; indirect exposure; soil; environment
