Drugs, drugs, drugs-we all take some form of pharmaceutical product at some point in our lives. Ever wonder what happens to those drugs once they go through your system and down the hopper? Or when you flush expired pills down the toilet or sink? Unfortunately water treatment plants are not designed to treat the “pharma deluge” that comes through our pipes. As a result, many waterways across the world have trace to high levels of pharmaceutical wastes found in them. Pharmaceutical waste has also been found in soil as well. What does this do to the environment? To fish and wildlife? Asian vultures (White-rumped Vulture (Gyps bengalensis), Indian Vulture (Gyps indices), and Slender-billed Vulture (Gyps tenuirostris)) were on the brink of extinction due to the consumption of the carcasses of cattle treated with Diclofenac, an anti-inflammatory drug. Diclofenac caused kidney failure in the birds, leading to population-level declines in a short period of time. Surveys in National Wildlife Refuges in the Northeastern part of the United States found 85% of male small mouth bass and 27% of male large mouth bass were intersex (when one sex develops the traits of the opposite sex). Researchers could not pinpoint the cause of this phenomenon but indicated that birth control waste could be a factor.
The larger impact of pharmaceutical pollution is still not clearly understood as more more of us rely on pharmaceuticals in our daily lives. What would a mix of drugs do to the environment? To us?
A recent study published in Scientific Reports looked at the impacts of artificial estrogen 17α-ethinylestradiol or EE2 (a synthetic estrogen commonly used in the pill) on different amphibian species. The researchers demonstrated that varying levels of exposure to EE2 can alter sexual development and feminize genetic males. The study focused on the African clawed frog (Xenopus laevis), the European tree frog (Hyla arborea), and the European green toad (Bufo viridian). A subset of each species was exposed to varying concentrations of EE2 and compared exposed groups to control groups. The laboratory conditions were a stand-in for conditions in the wild, particularly those near water treatment plants and drug manufacturing facilities. The study looked at both genetic and physical changes in the experimental groups. Sensitivity to the active hormone compound varied from species to species (between 15-100%). This study is one of the first of its kind to look at both physical and genetic changes. The permeable skin of amphibians appeared to soak in EE2 at a molecular level.
Researchers believe pharmaceutical waste could be one of the causes of amphibian decline. It is hard to contribute to the future of your species when all you have are a bunch of lady frogs.
About This Illustration: A colored pencil illustration of an albino African clawed frog. You can purchase a print of this illustration through my brand spanking new online store: https://the-science-of-illustration.myshopify.com/products/african-clawed-frog-print
For More Information:
BirdLife International (2013) Vultures are under threat from the veterinary drug diclofenac. Presented as part of the BirdLife State of the world’s birds website. Available from: http://www.birdlife.org/datazone/sowb/casestudy/156
Stephanie Tamschick, Beata Rozenblut-Kościsty, Maria Ogielska, Andreas Lehmann, Petros Lymberakis, Frauke Hoffmann, Ilka Lutz, Werner Kloas, Matthias Stöck. Sex reversal assessments reveal different vulnerability to endocrine disruption between deeply diverged anuran lineages. Scientific Reports, 2016; 6: 23825 DOI: 10.1038/srep23825