1-hydroxynaphthalene (aka 1-Naphthol) is a biological metabolite of naphthalene-based moth balls when said moth ball fumes are absorbed by the human body ... it might therefore be expected that excessive exposure to moth balls could be an inducer of rheumatoid arthritis ...
Poor moths :-) My grandparents used mothballs in their clothing closet in Norfolk. I haven't been exposed to any more since Fall of 1963. I did a blood test in grad school that consisted of adding a reagent of fine teflon balls to a drop of blood on the test slide. The test works by teflon balls becoming coated with antigens and antibodies from the blood. If you have both, the teflon balls coagulate on the test slide. My fellow students were about 10 minutes ahead of me and nobody was getting any coagulation results. I did my own blood same. Rocked the slide 3 times to mix the blood/reagent. It hardened into a mass on the slide. That was at age 20 in grad school. It was clear that RA was already underway. 800 mg of ibuprofen daily has slowed the damage to my joints and tendons. At nearly 67, the ibuprofen is becoming less able to keep the inflammation under control.