Jan Flora wrote:

My mom, a lifelong nurseryman, has COPD now. She's on oxygen 24/7,
since age 74. She's 78 now.
The MD's think it's because of lifelong exposure to vermiculite
in her greenhouses.
She never smoked and was never around smokers. She's an RN.

I'm a smoker.

Second hand smoke may have contributed also.