Question: In UK rivers, which pharmaceuticals show the strongest 'stickiness' to microplastics versus natural river sediment?

Louise Thurston answered on 16 Jan 2026:

Wow this is an amazing question, and the exact question I am trying to answer with my research!

So the ‘stickiness’ is controlled by the type of plastic, so what its chemical make up is like and the surface roughness of the plastic, and type of pharmaceutical – how its make up relates to how it acts in water. Different combinations of these factors lead to different levels of the ‘stickiness’. Common types of pharmaceuticals to stick to plastic are pain kills, (i.e. paracetamol), antibiotics and anti-inflammatories (i.e. ibuprofen).

However, scientists are starting to look at the mechanisms that allow pharmaceuticals to stick to plastics, is it the chemical make up or is it something else? For example, different bacteria can grow on different microplastics and I wonder if it is the bacteria that are controlling which pharmaceuticals stick and which don’t!

Long story short, that is a fantastic question and hopefully with my work I will be able to give you a better answer in a couple of years!