Wednesday, July 30, 2008

Doubts about sun exposure and skin cancer

The Seattle Times today points out that Washington State ranks fifth in the country for Melanoma (skin cancer), right up there with other northern long-winter places like Rhode Island and Vermont.  Meanwhile, the sunniest states like Arizona and Florida have the lowest rates (according to the CDC).

Look at the PDF map of skin cancer rates in Washington State.  If I changed the title of the graph to "Rainiest places in Washington", you wouldn't know the difference:  there's an almost direct correlation.  Eastern Washington (Yakima, Kititas, Walla Walla -- all those sunny places in the "rain shadow") have the lowest rates while Western Washington (especially the rain forest areas of Jefferson and the Olympic Peninsula) have the highest rates.

By the way, you can get all the local cancer data you want from the Washington State Cancer Registry.  Someday when I get more time, it would be fun to pull the data and compare it to rainfall and other variables.  For example: King County males have an incidence of 52 cases per 100,000 (females are 44).

I'm no expert, but the standard explanation seems completely backwards to me.  "People in northern or rainy climates forget to put on enough sunscreen, so they get burned more often--hence the higher cancer rates"?   Huh?  That sounds like a classic example of a "Just So" story -- data that contradicts your central thesis (sunshine causes cancer) becomes a reason to dig a deeper hole in absurd explanations rather than a chance to rethink your assumptions.

I wonder if anyone has compared things like sunscreen sales or usage by state and location.  Again, I have no idea about the medical research on this, but it seems to me that somebody might want to consider that it's the lack of sunshine that is the problem here.

1 comment:

Anonymous said...

According to American Cancer Society website, Melanoma cancers are NOT related to sun exposure, rather it is NON-MELANOMA cancers that are directly linked to sun exposure. This chart is for Melanoma cancers it would not correlate to this theory.

With that said, nearly 1,000,000 NON-MELANOMA cancers are diagnosised each year and fewer than 2,000 deaths annually. Also, it is not known HOW MANY PEOPLE as these types of cancers are comeback often in people who are diagnosed. All of this info can be found on the American Cancer Society website.

I did read somewhere that a marketing group found that sunscreen sales were about $650 million in 2006...some marketing group.

Also Vitamin D deficiencies are said to be around 3 in 4 people now!! And the symptoms and diseases from this are mounting!!

All the scare...increase SPF protection (major ^ sales), non-melanoma rates rising dramatically, and declining death rates(meaning ability to CURE), but VIT D deficiency is creating a huge expense...both to health, insurance, nursing home care (the elderly breaking bones from VIT D def), lost work hours, etc.

Not to diminish death or seem harsh, but there a whole lot of damage done by this sunscreen ramp up compared to less than 2,000 deaths annually that may or may not be from the sun.