I don't see where they took into account confounding factors like how much physical labor involves working in hazardous environments. Coal mining, for example:

I don't see where they took into account confounding factors like how much physical labor involves working in hazardous environments. Coal mining, for example: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6862248/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6862248/