Pyrogallol was used as to treat a skin disorder here (Australia) for many years. One patient did succumb to cancer after using it thickly on the whole back of his hands every day for something like 20 years (iirc). It's not used anymore for this purpose. Reasonable care in the darkroom makes it not a concern.
Hydroquinone is reputed to be bad in effluent because it affects marine life.