Pharmaceuticals are used globally in the treatment of humans and animals, but they can enter the environment and disperse widely in aquatic and terrestrial habitats with uptake into a range of organisms. The current issue of Philosophical Transactions B introduces the latest research investigating the risks that pharmaceuticals pose to the health and long-term viability of wild animals and ecosystems. “With thousands of pharmaceuticals in use globally, many of which are designed to have biological effects at low concentrations, they have the potential to have potent effects on wildlife and ecosystems” says Dr Kathryn Arnold, one of the editors of this issue. “Given their many benefits, there is a need for science to deliver better estimates of the environmental risks posed by pharmaceuticals.”
In some cases the effects can be very dramatic. In India, three species of vulture faced near extinction after eating the carcasses of livestock that had been treated with the anti-inflammatory drug diclofenac. With numbers of one species declining by more than 99.9% in just 15 years, this has now become a high profile conservation effort (such as this RSPB project). Richard Cuthbert and colleagues describe the scale of the problem, examine how alternatives to diclofenac have been received and provide hope that vulture populations may recover with a concerted conservation effort.
This issue also shows that effects can be more subtle but still have potentially significant impacts in the long-term, which may be underestimated in short-term studies. For example, this paper by Karen Kidd and colleagues describes the results of an experiment carried out to study the effect of synthetic oestrogen (used in the birth control pill) on the minnow population of an artificial lake specially designed for the research. Oestrogen causes feminization of wild male fish and, as might be expected, populations declined because of the direct impacts of oestrogens on their reproduction. The long-term results however also showed that cascading, indirect responses occurred in invertebrates and other fish because of changes in food supply and predation.
These two papers, along with the rest of the papers in the issue, can all be read for free during Open Access Week (October 20-26). Some of the papers in the issue are permanently open access, including this review of pollution from drug manufacturing, which looks at the high levels of discharges from pharmaceutical manufacturing sites and discusses the challenges with assessing environmental risks.
Want to learn more? Kathryn Arnold, co-editor of the issue and a former Royal Society University Research Fellow, spoke to us about the issue and research in this field and you can watch the video here. You can also read more in this article in The Guardian.
(Vulture image from ‘Switching Drugs for Livestock May Help Save Critically Endangered Asian Vultures. Gross L, PLoS Biology Vol. 4/3/2006, e61 http://dx.doi.org/10.1371/journal.pbio.0040061.’ Image: Goran Ekstrom. Image used under a CC BY 2.5 licence.)