Welcome to Piscatorial Bilge Rat. Interesting first post. I hadn't heard that sodium sulfite is a carcinogen. Will you tell us where you got that information? And what levels are a serious cancer risk to fish or mammals?

It seems to me that like most carcinogens, it would have to be very high levels. Both fish and mammals contain natural high levels of sodium. But some of us fishers have been exposed to it's sulfite form with fine dust while making powdered egg cures, mixing eggs in it, and putting eggs and other baits and scents on our hooks. Guides and other long time serious fishermen could have significant exposure. I would think that it's not enough to be of significant risk levels though. I'm not aware of any non-smoking fishers that have gotten lung cancer, nor have I heard of a higher rate of any type of cancer among NW salmon fishers. But let us know what you read about it and where it can be looked into. Thanks. ...

As far as it's danger to salmon/steelhead in the completely diluted form it occurs in water, I strongly believe the only harm to these fish occur when they eat it - with a hook attached. They live most of their adult lives in an immensely higher concentration of sodium chloride (salt), but aren't being killed or harmed by that. It would reason that a microscopicly infantesimal (sp?) amount of it in water would not have any affect at all.

RT