People are afraid of solar radiation, according to a new study that suggests some people have a hard time distinguishing between sun and other wavelengths of light.
Researchers at University of British Columbia, Victoria College and UBC’s Department of Earth and Atmospheric Sciences used a special computer-generated image of a sunburn to find the wavelength of light most visible to humans.
The scientists used the same image in the future, but this time with the sun’s radiation absorbed by a skin cell that is composed of a mixture of two different types of melanin, or pigments.
They found that skin cells from the same person with both types of pigment, a melanocyte, were more likely to have an identical wavelength of UVB light than cells from different people.
The researchers say that the results show how the combination of two types of pigments can make a person more susceptible to UVB radiation.
UVB is a more intense version of the sunburn-protection measure known as sunscreen.
UV rays are invisible to the human eye.
But scientists have long known that sunburns are more common among those with darker skin.
For years, scientists have linked this to a lack of vitamin D, a chemical that helps protect the skin from the sun and its harmful effects on DNA.
Vitamin D plays an important role in cell communication, as well as in cell formation, the formation of proteins and DNA, and the maintenance of healthy skin cells, the researchers say.
Vitamins D2 and D3 have been found to be higher in some people with sunburn than others.
So it’s not clear why darker skinned people tend to be more vulnerable to sunburn.
This new study suggests there may be some other factors at play, too, the scientists say.
“Our study is the first to show that the effects of UV radiation are more likely in those with lower vitamin D status than in those who have higher vitamin D levels,” said co-author James L. MacKay, a postdoctoral researcher in the Department of Atmospheric Sciences.
“This could be related to the fact that UV radiation is more likely when the sun is higher in the sky, when the earth is more reflective and when the ozone layer is thinner.
This may also explain the lack of association between vitamin D and sunburn in the current study.”
MacKay and his co-authors will publish their findings in the upcoming issue of the Journal of the American Academy of Dermatology.
The study also found that a skin layer that has been shown to protect against sunburn, called the skin barrier, is also less likely to be effective in mitigating the effects, as is a melanin layer that is present in the skin of people with darker pigmentation.
The team says the findings suggest there may exist a genetic factor that contributes to the inability of melanocytes to differentiate between sunburn and UVB.
“What we don’t know yet is whether these differences exist within individuals,” MacKay said.
“Our work shows that there is something going on that we have yet to discover.
It could be that there are genetic differences in melanocytes that can cause these differences in susceptibility to UV radiation.”
The research was supported by the U.S. Department of Energy’s Office of Science.