As Angharad hints, there's a plot-line here (Crystal used a variant - herbal tea - in in the early part of ICGHLT). But I'm not binning my sunblock just yet.

Sunlight is very destructive stuff - think of the damage to fabrics, building materials, vehicle components such as tyres...

The benefit (protection) currently outewaighs the danger, IMHO. That's based on something usually ignored by the doomsters: danger is the product of hazard and risk (ie multiply them together).

First there is no evidence - yet - of an efect in humans. (Note to flamers - I don't say 'there is no effect' just that so far there is nothing to indicate it.) But more important is the risk. We don't breathe water, and we don't bottom feed in the ocean or rivers (any readers who do either - tell me how you stop the water wrecking your mose/trackball, please?), so our exposure is probably a lot lower.

Then there is the question of relative bodyweight. I suspect that overall the 'risk' in the fish is several orders of magnitude higher than in man. Finally there is the very difficult question of susceptibility - the evidence cited may show a species-related variaton, and man (though ultimately from the same evolutionary tree) is a long way from fish (though not necessarily in this particular respect, of course. We just don't know enough).

I need to know more about that danger before I submit myself to the known danger of over-exposure to UV.

Xi