Risk assessment

Risk assessment

Why did I get into the field of health education? Lots of reasons, surely, but here is one.

At the start of my teaching career, I lodged with a couple in Andover. I was struck mostly by the opportunity to research the enormous houshold population of spiders, but I was also intrigued by several discussions we had about risks to health. One of the couple, as I recall, had already lost both parents to cancer, and he was very anxious about eating anything containing any sort of additives. I arrived home one day to find a row had broken out over a packet of frozen fish, because the label reported that it contained caseinates (milk protein), and it wasn't going to be touched until we were absolutely certain what caseinates were.

Now, having some caution about what's in your food seems absolutely rational, even if you didn't have a very personal, emotional reason for being wary. However, I used to have these discussions about the evils of additives while watching this chap drink a decent-sized Scotch whisky accompanied by a cigar.

What I needed then, and didn't have, was a clear statement about what are the major causes of death, and what are the known factors putting you at risk of those different fates. I'm not sure we know how much cancer is caused by food additives, but my guess was the alcohol and tobacco were contributing a lot more to his risk of cancer than anything in his food.  

What I needed, in fact, might have looked a lot like this:
This is a picture from the NHS Atlas of Risk at http://www.nhs.uk/Tools/Pages/NHSAtlasofrisk.aspx. You can see what are the most important causes of death, refine it for sex and region and age, and see what we know about risk factors - the causes of the causes, as it were. I don't think we're always very good at making judgements about probability and risk, even when they aren't very emotionally charged, but at least we have some evidence to go on, and that's quite a nice presentation of it.

I do like the charts and the ability to play with them, but I would like to have seen a bit about the errors in those estimates. Also, what would be the size of a big grey circle that could be labelled 'unknown'?