Ngaio Richards

Detection and drivers of exposure and effects of pharmaceuticals in higher vertebrates

Pharmaceuticals are highly bioactive compounds now known to be widespread environmental contaminants. However, research regarding exposure and possible effects in non-target higher vertebrate wildlife remains scarce. The fate and behaviour of most pharmaceuticals entering our environment via numerous pathways remain poorly characterized, and hence our conception and understanding of the risks posed to wild animals is equally constrained. The recent decimation of Asian vulture populations owing to a pharmaceutical (diclofenac) offers a notable example, because the exposure route (livestock carcasses) and the acute toxicity observed were completely unexpected. This case not only highlights the need for further research, but also the wider requirement for more considered and comprehensive ‘ecopharmacovigilance’. We discuss known and potential high risk sources and pathways in terrestrial and freshwater ecosystems where pharmaceutical exposure in higher vertebrate wildlife, principally birds and mammals, may occur. We examine whether approaches taken within existing surveillance schemes (that commonly target established classes of persistent or bioaccumulative contaminants) and the risk assessment approaches currently used for pesticides are relevant to pharmaceuticals, and we highlight where new approaches may be required to assess pharmaceutical-related risk.

Suspected Flunixin Poisoning of a Wild Eurasian Griffon Vulture from Spain

Exposure to residues of the nonsteroidal anti-inflammatory drug (NSAID) diclofenac present in livestock carcasses has caused extensive declines in 3 Gyps vulture species across Asia. The carcass of a wild Eurasian Griffon Vulture (Gyps fulvus) was found in 2012 on an Andalucian (Spain) game hunting reserve and examined forensically. The bird had severe visceral gout, a finding consistent with Gyps vultures from Asia that have been poisoned by diclofenac. Liver and kidney samples from this Eurasian Griffon Vulture contained elevated flunixin (an NSAID) levels (median = 2.70 and 6.50 mg/kg, respectively). This is the first reported case of a wild vulture being exposed to and apparently killed by an NSAID outside Asia. It is also the first reported instance of mortality in the wild resulting from environmental exposure to an NSAID other than diclofenac.

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

Pharmaceutical residues in the environment have the potential to harm wildlife. A population’s fragility or an animal’s secretive nature may preclude capture and the use of invasive/destructive sampling techniques that are typically used in a risk assessment. Conventionally favoured matrices gathered opportunistically from carcasses have a finite lifespan, thereby limiting the detection window. This multidisciplinary paper aims to promote the use of non-invasive approaches and optimize use of even the most degraded carcasses. We highlight a selection of promising alternative, unconventional and underutilized sample types that could be applied in environmental monitoring efforts and wildlife forensic investigations. With a focus on non-steroidal anti-inflammatory drugs (NSAIDs), now under increasing scrutiny in the freshwater and terrestrial environment, we first illustrate current sampling practices and gaps in knowledge by summarizing exposure of: 1) aquatic organisms to urban effluent discharged into waterways, and, 2) scavenging species to veterinary residues in livestock and other carrion. We then consider the merits and limitations of a range of alternative environmentally robust sample options that offer a broader detection interval for NSAIDs, with emphasis on hair, wool and feathers. The viability of eyes/ocular material, bone matter, fecal matter, injection sites, ingesta/pellets and scavenging/coprophagous insects are also discussed.

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

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.

First detection of an NSAID, flunixin, in sheep’s wool using GC–MS

Exposure to the nonsteroidal anti-inflammatory drug (NSAID) diclofenac resulted in the near extinction of three species of Gyps vultures on the Indian subcontinent. Other NSAIDs present in the environment, including flunixin, may pose a similar risk. In the course of a study to determine the feasibility of detecting NSAIDs in keratinous matrices (i.e., hair, nails and feathers) using GC-MS, wool opportunistically collected from a sheep treated with flunixin was analysed for residues. Flunixin was detected qualitatively in external wool wash and extract samples. While residues of veterinary agents and pesticides have previously been found in sheeps wool, our preliminary investigation provides the first instance of an NSAID being detected in this matrix. Here we provide the sample preparation methods and GC-MS parameters used to enable further refinement as part of ongoing conservation and consumer quality control measures.

Impacts of Pharmaceuticals on Terrestrial Wildlife

Essentially ubiquitous in our environment, residues of human and veterinary pharmaceuticals somewhat paradoxically represent an emerging and increasing risk to wild biota. Whilst in recent years a great deal of analytical effort has been expended to quantify the presence of many pharmaceutical contaminants, especially in freshwater systems, our real understanding of the risks posed to most clades of wildlife, aquatic and terrestrial alike, still lags behind. In particular, relevant field-based studies regarding possible chronic impacts in higher terrestrial wildlife (birds, mammals, reptiles, etc.) remain all too scarce. Yet, for example, over the past two decades Old World Gyps vultures on the Indian subcontinent have been virtually extirpated due to non-target exposure to a single synthetic pharmaceutical compound, diclofenac (a non-steroidal anti-inflammatory drug). Here, we highlight and discuss the myriad possible exposure routes to terrestrial wildlife, consider the analytical and monitoring approaches that are already in use or that could be used in future research, and reflect upon a selection of legislative approaches currently being applied to identified terrestrial impacts. Finally, with the ultimate aim of encouraging further applied ecotoxicology-based research in this emerging field, we highlight several priorities for future inquiry, with special emphasis on non-target effects in previously overlooked but potentially vulnerable or highly representative clades of wildlife exposed within environmentally relevant, real-world scenarios.

Using Scat Detection Dogs to Monitor Environmental Contaminants in Sentinel Species and Freshwater Ecosystems

Many contaminants are introduced into freshwater ecosystems worldwide. Preliminary investigations that focus on apex predator/sentinel species like otter and mink can inform more targeted follow-up studies. The feces of these elusive animals can be collected non-invasively for analysis of contaminants and complimentary genetics. Conservation detection dogs were used to locate otter and mink feces along five rivers in Montana for analysis of heavy metals, anthropogenic organic contaminants (AOCs) including pharmaceuticals and personal care products (PPCPs), polybrominated (PBDE) flame retardants, and genetics. With highest find rates of 6 and 20 fecal matter finds per km for otter and mink, respectively, and detection of all three focal contaminants in some fecal samples, this proved an excellent application of dogs. Recommendations for follow-up investigations are also provided.