TP2 Pharmaceuticals
255 Portland Ballroom
1:20 PM - 4:40 PM, Tuesday
() Evaluating Simple and Complex Mixtures Containing Pharmaceuticals in the Environment.
Mihaich, E1, Borgert, C2, Brighty, G3, Kortenkamp, A4, Laenge, R5, Snyder, S6, Sumpter, J7, 1 EM Mihaich Consulting, Durham, NC, USA2 APT, Alachua, FL, USA3 UK Environment Agency, Wallingford, UK, UK4 Univ. of London, School of Pharmacy, London, UK, UK5 Schering AG, Berlin, Germany, Germany6 Southern Nevada Water Authority, Henderson, NV, USA7 University of Brunel, Uxbridge, UK, UK
ABSTRACT- While most environmental assessments consider chemicals one at a time, the reality is that aquatic wildlife is exposed to mixtures of products in the environment. Determining exposure, effect, and ultimately risk of multiple stressors, and in this case, one particular type of stressor – pharmaceutical products – is an exceedingly complex task. Indeed, for mixtures of pharmaceuticals with various biological mechanisms of action, assessing the potential risks of combinations of these compounds is particularly challenging. However, we must move beyond the single chemical/single species approach to understand the potential impacts of these mixtures. In particular, we should be able to answer the question of when chemicals are present at concentrations where individually they would exert no adverse effect, what is the impact of the mixture as a whole? Multi-disciplinary technologies are necessary to define exposure to combinations of chemicals and the effects of those exposures to aquatic wildlife. Chemical identification approaches give us clues to what is in effluents and ultimately in the environment. However, it will be through the evaluation of the toxicity of these mixtures that we will begin to understand the biological response and thus, the risk of these mixtures. Whole-mixture studies, with surrogate mixtures or field collected effluents, or component-based approaches such as concentration or dose addition and independent action will be needed to utilize appropriate tests and endpoints to understand the ecological relevance of observed effects. Using information from mechanism of action studies in mammalian systems, statistically robust and useful endpoints for risk assessment are being identified and developed. Without this systematic approach it is unlikely that we will be able to successfully predict substance interactions in the environment. However, understanding the impacts of the mixture will give us the ability to propose relevant risk management strategies, if needed, to protect aquatic ecosystems.
Key words: mixtures, pharmaceuticals, effluents, biomarkers