Heavy metals are bad for you and linger in the body. That
being said, Ansel Adams noted that he handled the stuff constantly
through his entire career and suffered no apparent ill effects.
Proof by example doesn't count, but I personally know no photographers
who have suffered from any chemistry-related damage other than one
who developed metol allergy.
I'd like to urge people to retain some perspective. Act
sensibly - by all means wear gloves when handling selenium toner.
For what a box of latex gloves costs, it's a cheap defense. On
the other hand, I can't help but laugh at the photographers I know
who are insanely concerned about darkroom chemistry who:
a) smoke
b) commute 35 miles each way to work at 75mph
c) don't wear their seatbelts
I'm not convinced that photochemistry is as deadly as a
lot of people seem to think it is. Methinks it a lot a result
of our cultural overreaction to chemicals that follows from the
general level of chemological/pharmacological ignorance in our
society.
mjr.