Flushed away: why flu meds could make waves
Many of the drugs used to prevent or treat influenza are still active when they enter the wastewater system - and in the event of a pandemic, there could be large amounts of such substances heading towards wastewater treatment plants. Would the plants be able to cope? An international team of scientists, funded in part by the EU, has looked into the matter. The study, which analysed the ecotoxicologic risks of the medical response to a hypothetical flu pandemic, received EU support from three projects: DYNANETS ('Computing real-world phenomena with dynamically changing complex networks'), EPIFOR ('Complexity and predictability of epidemics: toward a computational infrastructure for epidemic forecasts') and EPIWORK ('Developing the framework for an epidemic forecast infrastructure'). As the 2009 H1N1 influenza pandemic unfolded, the public health community tracked its progress closely and sought to mitigate its impact on society. However, little attention was paid to the impacts of the medical response to the pandemic on the environment. In this study, researchers investigated the amounts of antivirals and antibiotics that might end up in our wastewater. Antivirals are used to prevent or treat flu, and antibiotics may also be prescribed to tackle secondary bacterial infections, such as pneumonia. However, our bodies don't absorb all this bounty completely. A large proportion of these drugs will, eventually, be flushed through our system - releasing a potent blend of biologically active substances straight into the nearest stream of wastewater. In the event of a pandemic, the usual trickle of such substances could transform into a torrent. To assess the risk to the water supply, the team combined a computer model simulating the amounts of drugs likely to be used during influenza pandemics of varying severity with a water quality model for the Thames catchment area in the UK. This enabled the researchers to predict the amounts of such substances to be expected in the wastewater stream. Another model was used to assess the possible effects on the area's rivers and wastewater treatment plans. High concentrations of antivirals and antibiotics could affect the microorganisms used in the treatment plants to remove unwanted nutrients from wastewater, inhibiting their growth and reducing the effectiveness of the facility. Hypothetically, insufficiently treated wastewater could enter the receiving rivers as a result. And, depending on the extent of the problem, this could have significant consequences for the quality of drinking water and for the environment, such as eutrophication or loss of aquatic life. The team's findings, published in the journal Environmental Health Perspectives, indicate that the ecotoxicologic implications of a mild pandemic are likely to be negligible. A moderate or severe pandemic could, however, cause environmental concerns. The team's projections indicate that the threshold for microbial growth inhibition would be exceeded for most wastewater treatment plants in the Thames catchment area, potentially affecting water quality for 5 to 40 % of the river. Lead author Andrew Singer, from the Centre for Ecology & Hydrology in the UK, highlights another consideration: 'The potential widespread release of antivirals and antibiotics into the environment may hasten the development of resistant pathogens with implications for human health during and potentially well after the formal end of the pandemic.' This said, Dr Singer emphasises the need for further research. 'We must develop a better understanding of wastewater treatment plants' ecotoxicity before the hazards posed by a pandemic influenza medical response can be reliably assessed,' he adds. In the event of a pandemic, flu vaccines would considerably reduce the health risks for individuals and the potential burden on society - and they would also help to limit any associated damage to the environment. '[...]the production and successful distribution of pre-pandemic and pandemic influenza vaccines could go a long way towards alleviating all of the identified environmental and human health problems highlighted in our paper, with the significant added benefit of reducing morbidity and mortality of the UK population. This latter challenge of vaccination is probably society's greatest challenge,' says Dr Singer, 'but also where the greatest gains can be made.' DYNANETS, EPIFOR and EPIWORK respectively received EUR 2.8 million, EUR 684,000 and EUR 4.9 million of funding under the EU's Seventh Framework programme (FP7).The EU's contribution to DYNANETS and EPIWORK was provided as part of FP7's support for research linked to information and communication technologies (ICT). The funding for EPIFOR took the form of a Starting Independent Researcher Grant awarded by the European Research Council (ERC) under the 'Ideas' Programme of FP7. Researchers from Indiana University (US), the Institute for Scientific Interchange (Italy), the University of Sheffield (UK) and Utrecht University (Netherlands) were also involved in this study.For more information, please visit:Centre for Ecology & Hydrology (CEH):http://www.ceh.ac.uk To view the abstract in Environmental Health Perspectives, click: here:DYNANETS project:http://www.dynanets.org/ EPIFOR project:http://www.epifor.eu/ EPIWORK:http://www.epiwork.eu/
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