Medicines, even life-saving ones, in the wrong place and in the wrong doses can be pollutants, according to a Mongabay-India report. These chemical concoctions that enter the human bloodstream and alleviate much human suffering also often end up seeping into rivers, lakes and estuaries – with scientists still unsure about its ills.

Pharmaceutical pollution has grown in leaps and bounds, including in newly urbanized, once pristine areas. Other common denominators of growing contamination include easy access to, and broad acceptance of, medicines globally. Despite growing awareness, there is no systematic reporting of waterway pollution by medicines, or impacts on ecological health. Currently, many human-excreted pharmaceuticals enter directly into waterways, or pass through existing wastewater treatment facilities.

The Mongabay-India report points out that India, for example, is now the world’s third-biggest pharmaceutical manufacturer by volume. In particular, it serves as a hub for generic drug production (versions of which replace more expensive formulations that are no longer patent-protected). The resulting cheaper medicines are readily available on India’s domestic market, while also being shipped worldwide. Around 40% of generic formulations sold in the US are supplied by India, according to one estimate.

While most people link medical waste to hospitals, medical facilities are not, in fact, the most significant source of pharmaceutical pollution. Though drug manufacturing plants do generate waste containing active pharmaceutical ingredients (APIs), it’s households that are by far the biggest source of pharma contaminants. Medicines, chemical formulations that alleviate much human suffering, can also be significant pollutants, with active ingredients often excreted from the human body and entering waterways.

Despite growing awareness among scientists, there is no systematic reporting of waterway pollution by medicines, or impacts on ecological health. Currently, many human-excreted pharmaceuticals enter directly into waterways, or pass through existing wastewater treatment facilities.

There are more than 4000 APIs in use today. All are compounds designed to evoke a biological response, to manipulate the functioning of living organisms. That fact alone means that APIs released into waterways have the potential to do environmental harm. However, the intensity of this contamination and of its impacts has not been well researched.

The Mongabay-India report highlights a recent global study titled ‘Pharmaceutical pollution of the world’s rivers’, published in June analyzed samples from 1000 sites along waterways in more than 100 nations, looking for 61 APIs. Their results suggest that concentrations of at least one API breached safe levels for aquatic life at nearly 40% of sites tested globally.

In India, Delhi’s sewage treatment plants are not designed for extracting pharmaceutical contaminants. Researchers detected a cocktail of 22 APIs, including metformin, in river water samples collected in the capital region. Despite being among India’s best-equipped facilities for tackling waste, the capital’s sewage treatment plants aren’t designed for extracting pharmaceutical contaminants. Researchers detected a cocktail of 22 APIs, including metformin, in river water samples collected in the capital region. In the new study, Delhi had some of the world’s highest average concentrations of APIs, alongside Addis Ababa, Ethiopia; La Paz, Bolivia; and Lahore, Pakistan.

The study states that environmental exposure to APIs can have negative effects on the health of ecosystems and humans. Studies assessing their occurrence are available for 75 of 196 countries, with most research conducted in North America and Western Europe. This leaves large geographical regions relatively unstudied. In this study researchers presented the findings of a global reconnaissance of pharmaceutical pollution in rivers. They monitored 1052 sampling sites along 258 rivers in 104 countries of all continents, thus representing the pharmaceutical fingerprint of 471.4 million people. Results showed that the presence of these contaminants in surface water poses a threat to environmental and/or human health in more than a quarter of the studied locations globally.

Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the sampling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, the study states that pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.