xicology, water chemistry , water quality and health, water treatment, pharmacology, and drinking-water regulation and policy was formed in 2009. Consultations were held in 2009 and 2010 with the Drinking-water Quality Committee and additional experts to review and summarize the available scientific knowledge and evidence. A literature review was a key source of evidence. This examined the fate and occurrence of pharmaceuticals in water, exposure to pharmaceuticals in drinking water, assessment of the human health risk associated with pharmaceuticals in drinking-water, removal of pharmaceuticals during wastewater and drinking-water treatment, and preventive management measures to reduce potential exposure to pharmaceuticals in drinking-water. This report contains the key findings and recommendations of the working group and consultations with experts in the Drinking Water Quality Committee. It aims to provide practical guidance and recommendations for managing the emerging concern about pharmaceuticals in drinking-water, taking into consideration the evidence from the literature review. More importantly, it emphasizes the need to prioritize this emerging issue in the overall context of water safety management, which includes microbial and other chemical risks that may threaten the safety of drinking-water.
Occurrence of pharmaceuticals in water are synthetic or natural chemicals that can be found in prescription medicines, over-the-counter therapeutic drugs and veterinary drugs. Pharmaceuticals contain active ingredients that have been designed to have pharmacological effects and confer significant benefits to society. The occurrence of pharmaceuticals in the environment and the water cycle at trace levels (in the range of nanograms to lowmicrograms per litre) has been widely discussed and published in literature in the past decade. The increase in detection is largely attributable to the advances in analytical techniques and instrumentation. Many surveys and studies have confirmed the presence of pharmaceuticals in municipal wastewater and effluents, and these have been identified as a major source of pharmaceuticals in drinking-water (Figure ES1).: STP is sewage treatment plant.
ES1: Fate and transport of pharmaceuticals in the environment (Ternes, 1998)
Routine monitoring programmes to test drinking-water for pharmaceuticals have not been implemented, as is the case for regulated chemical and microbial parameters. Generally, data on the occurrence of pharmaceuticals in drinking-water have resulted from ad hoc surveys or targeted research projects and investigations. Available studies have reported that concentrations of pharmaceuticals in surface waters, groundwater and partially treated water are typically less than 0.1 ? g/l (or 100 ng /l), and concentrations in treated water are generally below 0.05 ? g/l (or 50 ng/l). systematic studies will help to further our understanding of the transport, occurrence and fate of pharmaceuticals in the environment, especially drinking-water sources. Standardization of protocols for sampling and analysing pharmaceuticals would help to facilitate the comparison of data.
Human health risk assessment for pharmaceuticals in drinking-water are normally governed by stringent regulatory processes and require, rigorous preclinical and clinical studies to assess their efficacy and safety before commercialization. Therefore, pharmaceuticals are generally better characterized than other environmental contaminants.report reviews human health risk assessments of pharmaceuticals in drinking water conducted in the United Kingdom, Australia and the United States of America (USA). The approaches of acceptable daily intake (ADI) or minimum therapeutic dose (MTD) were adopted as the point of departure in these studies to assess potential risks to human health through exposure to pharmaceuticals in drinking-water. Margins of exposure (MOEs) were derived by comparing measured or modeled exposure levels in drinking-water with a reference exposure concentration, which was usually the ADI or MTD or sometimes a drinking-water equivalent level (DWEL). A judgment of safety could then be based on the magnitude of this MOE for the pharmaceutical under consideration. In other words, screening values ​​to determine whether further action is warranted could be derived from the ADI or the MTD, with uncertainty factors applied as appropriate.of the results indicated that appreciable adverse health impacts to humans are very unlikely from exposure to the trace concentrations of pharmaceuticals that could potentially be found in drinking-wa...
