Melanoma Education Foundation
Free melanoma lessons for middle and high school students

August 17, 2017 | Stephen Fine, Founder and President

Intermittent Sun Exposure and Melanoma Risk

Our efforts to increase melanoma education often include clearing up various misconceptions about the disease. Those who’ve never been taught much about skin cancer tend to make incorrect assumptions about it.

One of these beliefs is that melanoma incidence is highest in southern states, and among people who consistently spend time out in the sun. While it is true that skin cancer impacts both, it’s not the whole truth.

The sun’s harmful UV (ultraviolet) rays can be just as dangerous, if not even more so, to northern U.S. residents as they are to those who live in the south. And with reason.

There is a scientific hypothesis that those who inhabitant northern and central states are more prone to developing melanoma than people living in sunbelt states, due to intermittent sun exposure.

Scientists believe that the populations of sunbelt states can become more acclimated to UV rays because their skin is more likely to be exposed to them year-round. Non-medically, it’s similar to the way an auto mechanic at some point builds up a tolerance to the smell of gasoline.

Some examples of intermittent (sporadic, occasional) sun exposure include:

  • Spending much of the winter months indoors, then exposing skin to strong sunlight during the summer months
  • Spending the entire workweek indoors, and then full weekends outdoors
  • Northern and U.S. state residents vacationing in tropical or semitropical locations like Mexico, Florida, the Caribbean, or other areas where UV rays are particularly intense

Statistics show that when all ethnic groups are considered only one sunbelt state, Georgia, ranks within the Top 10 states for melanoma occurrences. And when only non-Hispanic Caucasians are included, only two states make that Top 10 list: Georgia again, and Hawaii.

This chart shows the Top 10 melanoma state rankings:

incidence rank 2014

Source: Center for Disease Control (CDC)

The skin cancers that are less serious than melanoma (basal cell carcinoma and squamous cell carcinoma) are more prevalent in sunbelt states.

It’s important to note that this information doesn’t mean that southerners shouldn’t continue to take sun-safety precautions; they certainly should. It means that northerners should remind themselves that the cold is no shelter from melanoma.