A canal cuts through the community and collects wastewater on its way to the sea. The water from the toilets is completely untreated and lies open. Rats scurry back and forth, picking up residues of the medication taken by local residents: antidepressants, antibiotics, painkillers and much more.
- In some cases, the medicines make the rats dare to approach people than run away. By coming close to us, there is a risk that they will also spread diseases, says Hussein Khalil, who researches human and ecosystem health at SLU.
He and his colleagues have recently received SEK 4.4 million from the Swedish Research Council to investigate the effect of drugs in wastewater on rats. The study site is a suburb of Salvador da Bahia in the northeastern part ofBrazil.
How the drugs affect the rats is largely unexplored. But Husein Khalil and Erin McCallum, also a researcher at SLU working on ecotoxicology, know that rats are a major problem from an earlier study they conducted in Brazil. The situation there was similar, with untreated sewage in open channels, and Mr Khalil discovered that the rats there carried the Seoul hentavirus. Many who fall ill gets something similar to a severe flu, though the virus hits the kidneys and can be fatal.
- We need to know more to help the authorities and people take the right measures, says Mr Khalil.
The research team will capture rats in Salvador and put GPS collars on them, to see how they move around the area to determine when and how they get the drugs. They will also set up cameras that react to movements to monitor the rats' behaviour and see if it is different.
The rats will then be recaptured and analysed to see what medicines they have in their bodies and what diseases they might be carrying.
They will also collect environmental samples such as water and soil, but also snails, which often ingest various substances in nature.
- This will give us a picture of what drugs and diseases the rats are ingesting and where. But also how it affects them. Which drugs can be assumed to make them more aggressive or active, for example,’ says Hussein Khalil.
This is a new field of knowledge, very little is known about how rats are affected by drugs, and he wants to contribute new knowledge. But above all, Hussein Khalil hopes that the research will benefit the people in these areas.
- The problems with sewage and rats are obvious. With the study, we can hopefully show it with such clarity that local authorities feel compelled to act to change the situation, says Hussein Khalil.
