의약물질의 환경위해성 관리방안 연구

Abstract

Abstract Pharmaceuticals are indispensable as they cure those who suffer from disease and their availability improves the quality of life. Veterinary medicines are also widely used to treat disease and improve the productivity of livestock farming. However, during their use, human and veterinary pharmaceuticals have the potential of being released into the environment. In recent years, the possible environmental (ecological) risk of pharmaceuticals in the aquatic environment has become a matter of increasing public concern. Potential ecological effects from the presence of pharmaceuticals in the environment have generally focused on the following two concerns: 1) the release of antibiotics into the environment increases the chance of antibiotic-resistant microorganisms and promotes the spread of resistant genes, and 2) when drugs affecting hormonal systems reach organisms in nature, it may result in a reproductive disturbance in the ecosystem. Environmental risk assessment (ERA) is considered the best scientifically based approach for evaluating the potential effects of contaminants on communities and ecosystems. The process includes problem formulation, exposure assessment, effects assessment, and risk characterization. Accurate exposure assessment is a key element of ERA. However, exposure assessment has been hampered by the continuing difficulties and expense involved in measuring the low ppt concentrations of pharmaceuticals in the environment. In addition, real-time monitoring data provides only snapshots of contaminant concentrations. Thus, when faced with the task of assessing the environmental exposure of pharmaceuticals, the utilization of exposure models becomes essential. The first objective of this report is to apply computerized exposure models to assess the environmental concentration of human and veterinary pharmaceuticals in the Han River and the Kyungahn stream, a major branch of the Han River. PhATETM and SWMM are identified as appropriate exposure models for this study based on data availability, researchers’ previous experience with models, and accessibility to models. The models investigated in this study intend to provide rapid predictions regarding the potential environmental fate of a compound. In this study, model-predicted PECs are compared to field data that either have been published previously or were empirically measured during this study (Chapters 2, 3, and 4). A second objective of this study is to estimate the total environmental concentration of pharmaceuticals, from both human and animal use, by integrating the simulation results from PhATETM and SWMM. Although the introduction routes into the environment for veterinary pharmaceuticals are different from those for human use, both human and animal pharmaceuticals eventually end up reaching surface water. Therefore, estimating the environmental concentration of such pharmaceuticals based solely on either human consumption or animal consumption results in an underestimation of environmental exposure. In this study, a workable framework to estimate PECs for these dual-usage pharmaceuticals is suggested (Chapter 5). Finally, a third objective is to perform an environmental risk assessment (ERA) for selected pharmaceuticals. Hazard quotients (the ratio of EC to PNEC) based on PECs are compared to those based on MECs. This exercise will demonstrate the applicability of modeling approaches in the risk assessment of pharmaceuticals in the environment. The potential benefit of using molecular level biomarkers to assess pharmaceutical toxicity is also discussed and methods are presented (Chapter 6). In order to minimize the deposition of pharmaceuticals into the environment, potential risk management actions are suggested; disposal labeling on pharmaceutical products, discharge guidelines for pharmaceutical manufacturing facilities, pretreatment of hospital wastewater, modification of wastewater treatment plant infrastructure or operating parameters, standardizing guidelines for the handling and disposal of unused medicine, and efficient dispensing practices and packaging (Chapter 7).