Cosmosophy: French farmers do have less cancers and less blood cancers than the non farmer population...

It is highly improbable, due to the large use of glyphosate, that this molecule increases the rate of NHL and/or other cancers.

But there are pieces of evidence linking waste incinerators and their byproducts in the increased rate of NHL.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2587460/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6720705/

Pesticides? rather improbable even in other countries
https://www.mdpi.com/1660-4601/11/4/4449/htm

Cosmosophy