Dangerously High Levels of Pharmaceuticals in Freshwater

The concentration of medicines in freshwater has increased considerably in the last twenty years. The amount of antibiotic ciprofloxacin in water is even so high that there is a risk of harmful ecological effects. This appears from research by environmental experts at Radboud University. The research will be published in Environmental Research Letters on February 22nd . 'We show that this should be measured in more places in the world.'

'Information availability is a major problem in the proper mapping of the risks of medicines in the environment worldwide. Although there are models that can predict concentrations of drugs in the environment on a detailed scale, such as the ePiE model , these can often only be used for places we have a lot of information about, such as European rivers', says Rik Oldenkamp, ​​lead author of the publication.

With the new model of the researchers, which builds on an existing model with less high resolution, it is indeed possible to make global predictions at the level of individual ecoregions.

Together with colleagues, he mapped out the risks of two medications in freshwater worldwide for the first time.

Harmful concentrations

For the two substances studied in the study - carbamazepine, a medicine against epilepsy, and ciprofloxacin, an antibiotic - the environmental risks were 10 to 20 times higher in 2015 than in 1995. The increase in human use of ciprofloxacin in particular increases the risks worldwide.

'The concentrations of this antibiotic are harmful to the bacteria in the water, which in turn play an important role in all kinds of food cycles. In addition, antibiotics can also have a negative influence on the effectiveness of bacterial colonies that are used in water purification, 'says Oldenkamp.

Antibiotic resistance: also an environmental problem

Antibiotic resistance is a topic that has been on the agenda for several years on the agenda of the World Health Organization (WHO) and the General Assembly of the United Nations. Oldenkamp: 'In general, it is seen as a problem for the health sector: resistant bacteria can be spread within hospitals or via livestock farming. But little is known about the role of the environment in this problem, although it is essential. After all, people are also exposed to bacteria through wastewater treatment, rivers and lakes. '

More measurement data in high-risk areas

'Especially in ecoregions in densely populated and dry areas, such as in the Middle East, we predict a high environmental risk in our model, although those are the places where there is little data available about medication consumption and water concentrations,' says Oldenkamp. The researchers predicted human drug consumption in these areas using regression models based on consumption in other countries and socio-economic and demographic information, and linked this to information about, among other things, water flows and how many people are connected to water purification.

Oldenkamp: 'That new measurement data is needed in these areas, shows us the model. Ultimately, this model provides a first point of application with which we can gain more insight into the risks of all kinds of medicines in the environment worldwide. '

This article has been republished from materials provided by Radboud University. Note: material may have been edited for length and content. For further information, please contact the cited source.

Reference
Aquatic risks from human pharmaceuticals - modeling temporal trends or carbamazepine and ciprofloxacin at the global scale. 2019.  Environ. Res. Lett. 14 (2019) 034003 https://doi.org/10.1088/1748-9326/ab0071.