d effective means of risk management. Preventive measures need to be applied as close as possible to the source of the risk and hazard. Inappropriate disposal practices, such as flushing unwanted or excess drugs down toilets and sinks and discarding them into household waste, are common and may be the main contributors to pharmaceuticals in wastewater and other environmental media, such as surface waters and landfill leachate. Preventive measures, such as policies promoting or regulations governing disposal practices at concentrated point sources (eg health-care and veterinary facilities), can reduce the amount of pharmaceutical waste entering water bodies. In addition, takeback programmes, guidance and enhanced consumer education will support efforts for the proper disposal of medicines and reduce the impact of pharmaceuticals entering our water sources.
Conclusions literature and national studies have shown that concentrations of pharmaceuticals in surface water and groundwater sources impacted by wastewater discharges are typically less than 0.1 ? g/l (or 100 ng/l), and concentrations in treated drinking-water are usually well below 0.05 ? g/l (or 50 ng/l). There are few comprehensive, systematic studies on the occurrence of pharmaceuticals in drinking water. Limited data on the occurrence of pharmaceuticals in drinking-water are a challenge in assessing potential human health risks from exposure to trace concentrations of pharmaceuticals in drinking-water. Several approaches to screen and prioritize pharmaceuticals have been published in peer-reviewed literature. These approaches usually apply the principles of the point of departure to derive a margin of exposure between the reported worst-case exposure and the MTD, the ADI or sometimes the DWEL. Targeted investigations conducted in the United Kingdom, the USA and Australia found that pharmaceuticals are largely present in drinking-water at concentrations several orders of magnitude (more than 1000-fold) below the minimum therapeutic dose and largely below the calculated ADIs and DWELs. The substantial margins of safety for individual compounds suggest that appreciable adverse impacts on human Health are very unlikely at current levels of exposure in drinking-water. From a treatment perspective, pharmaceuticals are not unusual organic chemicals, and treatment removal rates depend on the physical and chemical properties of the compounds. Conventional treatment processes with chlorination (free chlorine) can remove about 50% of these compounds, whereas advanced treatment processes, such as ozonation, advanced oxidation, activated carbon and membranes (eg reverse osmosis, nanofiltration), can achieve higher removal rates; reverse osmosis , for example, can remove more than 99% of large pharmaceutical molecules.
Recommendations quantities of pharmaceuticals in drinking-water are very unlikely to pose risks to human health because of the substantial margin of exposure or margin of safety between the concentrations detected and the concentrations likely to evoke a pharmacological effect.over pharmaceuticals should not divert the attention and valuable resources of water suppliers and regulators from the various bacterial, viral and protozoan waterborne pathogens and other chemical priorities, such as lead and arsenic . current levels of exposure to pharmaceuticals in drinking-water also suggest that the development of formal guideline values ​​for pharmaceuticals in the WHO Guidelines for Drinking-water Quality is unwarranted.monitoring of pharmaceuticals in water sources and drinking-water at the national level and the installation of specialized drinking-water treatment infrastructure to reduce the very low concentrations of pharmaceuticals in drinking water are not currently deemed necessary given the limited additional health benefits. However, where specific circumstances, such as a catchment survey, indicate a potential for elevated concentrations of pharmaceuticals in the water cycle (surface water, groundwater, wastewater effluent and drinking-water), relevant stakeholders could undertake targeted, well-designed and quality- controlled investigative studies to obtain more information to assess potential health risks arising from exposure through drinking-water. If necessary, screening values ​​could be developed and an assessment of the need for treatment enhancement could also be considered within the context of other risks and priorities using the water safety plan.exposure to pharmaceuticals through drinking-water can be reduced through a combination of preventive measures, such as take-back programmes, regulations, public guidance and consumer education to encourage the ...
