Glasgow Session on Environmental Exposure and Effects of Pharmaceuticals and Veterinary Medicines – Aquatic and Terrestrial Ecotoxicology
Ross Brown, AstraZeneca, Alistair Boxall, University of York, Gerd Maack, UBA, Jeanne Garric, IRSTEA
This session reviewed current progress in understanding and predicting environmental exposure, bioavailability and the effects on ecological and human health of pharmaceuticals and veterinary medicines in different compartments: marine, freshwater and terrestrial.
Key underlying themes:
- Targeting risk assessments and identifying potential impacts/priority compounds based on data extrapolation
- Measuring and simulating (of realistic, long-term and low-level) exposure
- Measuring relevant and reliable effects endpoints linked to adverse outcomes
- Determining the fate and effects of transformation products and metabolites
- Determining the role of the environment in the development of antibiotic resistance
Recent improvements in analytical detection have revealed that pharmaceuticals and their metabolites, or transformation products, can enter the environment via water, sewage, manure and animal carcasses and may disperse through the food chain. Pharmaceuticals are designed to alter physiology at low concentrations and therefore have the potential to be potent environmental contaminants. Environmental research efforts should be targeted based on exposure and risk of adverse effects in susceptible populations. During the last five years, several environmental monitoring studies have reported the various effects of pharmaceuticals on wildlife, the clearest example of adverse population-level effects being the impact of the anti-inflammatory drug diclofenac on vulture populations in Asia.
Important areas of new research include:
- Development of exposure models to identify hotspots or extrapolate measured pharmaceutical concentrations across wider geographical areas and food chains
- Identification of biomarkers to help provide a causal link between exposure and adverse effects
- Comprehension of the combined and relative risk of pharmaceuticals and other environmental stressors
The importance of biological, physical and chemical interactions (e.g., for ionisable pharmaceuticals) is being evaluated in receiving waters and agricultural soils being treated with biosolids (as fertiliser) and/or irrigated with wastewater. These dynamic interactions determine the uptake and fate of pharmaceuticals in ecological and human food chains.
The development of antibiotic resistance in treated farm animals, slurries and field soils is also an important and growing area of research, potentially affecting environmental and human health.
Research and regulatory work continue to focus primarily on the freshwater environment, driven partly by growing concerns over climate change and the scarcity versus availability of clean freshwater in some regions. There is also increasing interest in the coastal zone, where human habitation and aquaculture are intensifying, leading to the increased use and discharge of pharmaceuticals. While the bulk of studies still have a Western focus driven by, for example, the Water Framework Directive and Pharmacovigilance Directive, attention is moving to developing countries in the East, where pharmaceutical manufacturing and use are increasing, placing growing pressures on infrastructure and sewage/effluent treatment.
Authors' contact information: Ross.Brown@astrazeneca.com; firstname.lastname@example.org; email@example.com; firstname.lastname@example.org
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