Medicine in water supply: An emerging concern
While millions of people in the world are struggling to access safe drinking water, drugs contamination in the supply water has been emerging as a rising concern. More than 100 different types of medicine have been detected in lakes, rivers, reservoirs and streams throughout the world — Asia, Australia, Canada, Europe, USA — even in Swiss lakes and the North Sea. The concentrations of prescription drugs and over the counter drugs in the water supply are very low and far below the levels of a medical dose. But the presence of so many drugs in drinking water is heightening worries among scientists for long-term consequences to human health. According to World Health Organisation (WHO), medicine can be introduced into water sources through sewage, which carries the excreta of individuals and patients who have used these chemo-therapeutic agents, from uncontrolled drug disposal (e.g. discarding expired drugs into toilets) and from agricultural runoff comprising livestock manure. Most tap water is not treated in a way that can get out pharmaceutical drugs or if treated they do not remove all drug residue. Experts are investigating the possible long term health effects of drinking such water. Current observations suggest — it is very unlikely that exposure to very low levels of pharmaceutical products in drinking-water would result in appreciable adverse risks to human health. But it could be an emerging public health problem if the concentration rises and also for wildlife. The most appropriate approach to minimise the presence of pharmaceutical products in drinking-water and reduce human exposure is to prevent or reduce their entry into water bodies as far as reasonably practical. According to WHO, concentration of the vast majority of pharmaceutical drugs into the water bodies can be reduced through natural processes (e.g. adsorption onto sediment, solar photo-degradation and biological degradation) or during subsequent drinking-water and wastewater treatment processes. Conventional water treatment processes, such as chlorination can also reduce the burden half and improved system to treat water will help preventing entry of drugs into water supply chain. Drugs in drinking water are emerging. We need to act before it evolves as a major public health problem.
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