Qualitative detection of the NSAIDs diclofenac and ibuprofen in the hair of Eurasian otters (Lutra lutra) occupying UK waterways with GC–MS

Abstract

The pervasiveness of pharmaceuticals such as nonsteroidal anti-inflammatory drugs (NSAIDs) in the aquatic ecosystem through the discharge of wastewater, and their potential to biomagnify within this ecosystem, is now recognised. Residues of diclofenac and ibuprofen are currently being detected in surface waters and aquatic organisms throughout the UK and Europe. However, the levels of these residues in fish and other aquatic organisms, particularly lower trophic level prey species, have not yet been determined. While exposure to diclofenac is known to adversely affect fish, the degree to which other aquatic organisms are exposed and impacted through continuous ingestion of contaminated prey and interaction with the aquatic habitat remains unknown. The extent and effects of exposure to ibuprofen also remain largely unknown. As an exploratory subset of a broader study to investigate the detectability of diclofenac in alternative biological matrices, we analysed hair samples from Eurasian otters (Lutra lutra, n=28) for residues of the two NSAIDs using GC-MS. The otters were collected from six counties in England as part of an ongoing otter health monitoring project at the Wildlife Veterinary Investigation Centre in Chacewater, UK. Diclofenac was qualitatively detected in five hair wash and 15 extract samples, and ibuprofen was determined to be present in at least two of the hair extract samples. Here, we provide preliminary evidence that otters are exposed to both NSAIDs and argue for further studies to identify residue loads in the otters and their prey to fully assess the pervasiveness of these compounds and potential risks of ongoing exposure to them.

Merging Wildlife and Environmental Monitoring Approaches with Forensic Principles: Application of Unconventional and Non-Invasive Sampling in Eco- Pharmacovigilance

“…Species that come into contact with pelage orally, either when collecting it for nesting purposes, or when feeding on a carcass, may be exposed to residues of topically applied agents. Similarly, our opportunistic analysis of otter hair showed the viability of analyzing surface hair washes to identify dermal exposure and refine the information obtained regarding ongoing exposure to compounds of interest within a given environment [79].…”

“…Based on their assessment of renal lesions observed, these authors have suggested that future studies investigating renal disease in otters should consider exposure to nephrotoxic agents, such as NSAIDs [78]. This recommendation was also based on a concurrent exploratory study that investigated the viability of using hair to determine exposure to diclofenac and ibuprofen in river otters [79]. In this study, hair was opportunistically collected from a subset of the dead otters (n=28) recovered for necropsy, and both NSAIDs were qualitatively detected.…”

“…This reinforces the case for adopting innovative, non-invasive sampling and monitoring techniques and strategies. While it is straightforward to collect a given volume of hair from a carcass in-hand (e.g., 50 mg; [79]) minimally invasive devices such as hair snares/traps may require a significant investment of time for a relatively low yield of hair [11,17]. By contrast, fecal matter can be recovered completely non-invasively and with comparative ease [18].…”

Bioassays Currently Available for Evaluating the Biological Potency of Pharmaceuticals in Treated Wastewater

“…Recently diclofenac has been qualitatively detected in the hair of Eurasian otters Lutra lutra indicating that wildlife is being exposed to this compound [107]. The most severe adverse effects of diclofenac though were found in three species of vultures the Indian white-rumped one (Gyps bengalensis), the Indian one (Gyps indicus), and the slender-billed one (Gyps tenuirostris) in India and Pakistan causing a population decline [108,109].…”

Biodegradation of emerging pollutants: focus on pharmaceuticals

“…The term emerging pollutants refers to natural or synthetic substances found in ecosystems. Their ecotoxic impacts on the environment and humans are already known, whereas the occurrence and environmental fate are uncontrolled or unregulated 1,2 Since the late 1990s, pharmaceutical pollutants present in natural ecosystems have been seen as an emerging environmental prob- fish and fauna, the habitat and food for these animals 15 . Several studies reported on feminisation of male fish caused by a synthetic hormone 17-a-ethinyl-estradiol in their habitat 16,17 .…”