Naproxen and Its Phototransformation Products: Persistence and Ecotoxicity to Toad Tadpoles (Anaxyrus terrestris), Individually and in Mixtures

Abstract

Although pharmaceutical pollution is a global environmental concern, much remains unknown about the transformation of pharmaceuticals in the wild and their effects on wildlife. In the environment, pharmaceuticals typically transform to some extent into different, structurally related compounds. Pharmaceutical transformation products resulting from exposure to sunlight (i.e., ultraviolet radiation) in surface waters are of particular concern; these products can be more hydrophobic, persistent, and toxic than their parent compounds. In the present study, naproxen, a widely used nonsteroidal anti‐inflammatory drug, and its phototransformation products were studied to assess the overall persistence and photochemical fate of naproxen. Southern toad (Anaxyrus terrestris) larvae were used as model aquatic vertebrates to evaluate the acute toxicity of naproxen and its phototransformation products singly and in mixtures. The phototransformation products were observed to be more persistent and more toxic than naproxen itself. The slower phototransformation of the phototransformation products relative to naproxen suggests a greater potential to accumulate in the environment, particularly when naproxen is continually released. Mixtures of naproxen and its phototransformation products, in ratios observed during phototransformation, were more toxic than naproxen alone, as predicted by the model of concentration addition and the greater toxicity of the phototransformation products. Together, these results indicate that the ecological risk of naproxen may be underestimated by considering environmental levels of naproxen alone. Environ Toxicol Chem 2019;38:2008–2019. © 2019 SETAC.

UV-visible photodegradation of naproxen in water – Structural elucidation of photoproducts and potential toxicity

“…In a previous study on UV photodegradation of Naproxen by Cory et al., only PP2 and PP3 were detected though the experimental conditions were quite similar to those used in the present work. 20 Like in the present study, both photo-transformation products of Naproxen were found to be more stable than Naproxen itself when exposed to simulated sunlight; their toxicity was investigated towards toad tadpoles and they have been shown to be much more toxic than the parent molecule.…”

Environmental fate and effects assessment of human pharmaceuticals: lessons learnt from regulatory data

“…Studies on the occurrence and fate of TPs show that, in addition to the API, many environmental organisms are exposed to TPs (e.g. [97][98][99]).…”

Cell Adaptations of Rhodococci to Pharmaceutical Pollutants

“…Most often and in relatively low concentrations (from ng/L to µg/L),those are massively consumed antibiotics, anti-inflammatory drugs (NSAIDs), hormones, antispasmodics, antihypertensives, anticancer agents, anticonvulsants and antidepressants;and also statins and antidiabetic drugs increasingly usedowing to the spread of sedentary lifestyles associated with urbanization [1]. As reported in a number of studies,pharmaceutical pollutants with pronounced biological activity and high chemical resistance, have negative impacts on invertebrates [2][3][4], vertebrates [5,6], plants [7,8], and also disrupt the structure and functioning of ecosystems [9,10]. However, the nature of such impacts of pharmaceutical compounds on natural microorganisms, which represent a native system of "primary response" to xenobiotic load in open ecosystems, is still insufficiently studied.…”