Reports suggest such is the medicine residue in water bodies that fish is changing character; oral contraceptive residue makes them ‘feminised’

Imagine this pollutant: It treats illness, but when it escapes into the environment it remains there; unregulated, it keeps affecting millions, making them further ill. Many of them end up with damaged organs.

It not only impacts unsuspecting humans, but also other living beings. To sum up, the new pollutant is an agent of mass health disruption — it is the residue of our medicines, or pharmaceuticals, left unregulated and untreated.

A new study by the Organisation for Economic cooperation and Development (OECD) has found that a “vast majority” of the 2,000-odd active ingredients in use in human and veterinary medicines are not regulated. They have not been yet evaluated for their risks once they escape to the environment. Every year more and more such active ingredients are approved for use. Thus, it adds to the pile of such unregulated residues in the environment.

Residue of medicines enters into our environment — water bodies, streams, air and food — at all the stages of medicine preparation starting from manufacturing, uses and disposal. But the biggest source of it is the natural process of medicine absorption by human body.

Between 30 and 90 per cent of the medicines that we consume are flushed out through excreta and urine. These residues have active ingredients present in the consumed medicines. Once they are dumped in sewage and streams untreated they just find their ways into our environment, into bodies of people. Expired and unused medicines are also thrown away in dumpsites and landfills.

For instance, in the United States, 33 per cent of the 4 billion medicines prescribed each year are dumped as waste. Our sewage systems are not just designed to treat such active ingredients thus making their presence more widespread.

Such residue or active ingredients of medicines have been found in surface water, groundwater and tap water across the world, according to the study. In India, 31-100 residues were found in various water sources.

“Because pharmaceuticals are designed to interact with living organisms at low doses, even low concentrations can affect freshwater ecosystems,” according to the report. It means residue of a medicine legitimately used by a person for a disease enters the body of another human who doesn’t have the same health issue. In simple term, it is similar to taking wrong medicine for wrong disease or even consuming for no reasons at all. And it has impacts.

The OECD report has quoted a study that shows that active substances in oral contraceptive have “caused the feminisation of fish and amphibians”. This study further says that residue of psychiatric drug fluoxetine has fundamentally changed behaviour of fish by making them “less risk-averse”. In an upcoming book by Down To Earth and Delhi-based non-profit Centre for Science and Environment, such residues are also leading to antimicrobial resistance. It is estimated that by 2050, 10 million people will die due to antibiotic resistance, mostly people living in developing countries. India is the top consumer of antibiotics in the world.

What adds to this crisis is seer absence of scientific knowledge of these ingredients’ long-term impacts in the environment. For example, most of them have not been studied for their toxicity once in environment. Even, we don’t much about their lives in the environment. Close to 88 per cent of human pharmaceuticals do not have comprehensive environmental toxicity data.

Unlike when prescribed for consumption for specific disease by one person, in the environment residue of multiple medicines mix freely creating a cocktail whose impacts or interaction with humans are hardly known. “There is growing evidence that mixtures of pharmaceuticals possess a joint toxicity greater (i.e. additive effects) than individual toxicities,” says the report.