I'd be curious to know which chemicals have been proven to cause Parkinson's Disease. Can you provide your source of information?
There's a multitude of info on it. The University of Stanford is credited for having done the first research in the association of chemicals with Parkinson's Disease.
For the most part, their original research was focused predominately on insecticides. Now, it is old news.
But, here's a couple of more recent experts comments.
"Men are more than twice as likely to have PD when exposed to chemicals". Dr Walter Rocca, Mayo Clinic.
(Hmm, it seems women have a more stable production of dopamine, them thar brain neurons! LOL)
Dr. Zalman S. Angus MD, Professor @ U of Penn School Of Medicine contributes to MEDPAGE..."several studies have reported association of PD with pesticides...metals, solvents, paints, glues, and printing chemicals. (Then there were some studies that came to no conclusion as to the relationship of chemicals,
other than pesticides with PD).
I could go on, but you get the point. I don't know that any chemicals used in a hot tub are harmful. I'm not saying they are.
My philosophy is natural is better. That's why if there is a natural product out there that will do the trick, I'd prefer to use it. So, if anyone knows of a natural solution to keeping the hot tub clean and bacteria free, I'm all ears.