Hello,
Many thanks for your response. The reason why I wanted to create buffers is the following:
my next step will be adding a layer with addresses of study participants. By mapping the buffers, I could visualize the approximated severity of pollution for each participant. But now that I think about it, I could of course do exactly the same with the graduated symbols, simply by changing the sizes and transparency.
In order to assign more accurate pollution levels to each participant, I could then - in the next step - apply inverse distance weighting approach.
Thanks for sharing the links with me! Interpolation of the data looks like a good way to present my results in the first place, before I start with the epidemiological analysis.
Best,
Gosia