I never thought of these things, I will check as our home is 55 years old.
But when he goes to his mom's house 4 hours away in Tucson, for a week, he is still in immense pain but her older house could have items above as well.

Most recent experience is when we flew to MN and that night/next day his pain was almost gone then when we returned to AZ, normally pain returns immediate but this time there was a delay in his body for 1 1/2 weeks till pain returned which was a mystery as to "why".