The challenge of managing pharmaceuticals in water

Pharmaceuticals are an important element of medical and veterinary practice, and their beneficial effects on human and animal health, food production and economic welfare are widely acknowledged. Yet an area lacking in common understanding is what happens when pharmaceuticals are constantly discharged into the environment, through manufacturing, consumption and excretion, and the improper disposal of unused or expired products.

A new OECD report entitled Pharmaceutical Residues in Freshwater: Hazards and Policy Responses warns that too little is being done to prevent pharmaceutical residues seeping into soil, water supplies, fresh water ecosystems and the food chain, and to assess the potential risks. The author of the report, Hannah Leckie, OECD environmental directorate, says pharma residues, such as hormones, anti depressants and antibiotics, have been detected in surface water and ground water across the globe. High levels of these residues have been found down stream of pharmaceutical manufacturing plants, and conventional wastewater treatment plants are not designed to remove pharmaceuticals in waste water. Veterinary pharmaceutical residues from agriculture and aquaculture can enter water bodies without any treatment.

The report also reveals the vast majority of the roughly 2 000 active pharmaceutical ingredients (APIs) currently used in human and veterinary pharma products have never been evaluated for environmental risks. Several dozen new APIs are typically approved for use each year.

A CHALLENGE TO MANAGE

A study cited in the report estimates 10 percent of pharmaceuticals have the potential to cause environmental harm.

Those of greatest concern include hormones, pain killers and antidepressants. Concerns over rising antibiotic content in waste water fuelling the spread of drug resistant microbes have been raised at G20 level.

Pharmaceutical residues can enter the environment during the manufacture, use and disposal of medicines. When humans and animals ingest medicines, between 30 and 90 percent of the ingredients are excreted as active substances into the sewage system or the environment. Some medicines are thrown away unused and end up in landfill, or they are disposed of in the bathroom and end up in sewer systems. In the US, an estimated one third of the four billion medicines prescribed each year ends up as waste. Conventional waste water treatment plants are not designed to remove pharmaceuticals, and water resources are not systematically monitored for residues.

Because pharmaceuticals are intentionally designed to interact with living organisms at low doses, even low concentrations in the environment can have unintended, negative impacts on fresh water ecosystems. For example, active substances in oral contraceptives have caused the feminisation of fish and amphibians; psychiatric drugs, such as fluoxetine, alter fish behaviour making them less risk-averse and vulnerable to predators; and the over-use and discharge of antibiotics to water bodies exacerbates the problem of antimicrobial resistance. The latter has been declared by the World Health Organization as an urgent, global health crisis projected to cause more deaths globally than cancer by 2050.

Unless adequate measures are takento manage the risks, the situation is setto worsen as the use of pharmaceuticals rises with ageing populations, advances in healthcare, rising meat and fish production, and as emerging countries increasingly administer antibiotics to livestock.