A new study suggests that a lack of exposure to sunlight may increase the risk of lung cancer.
People who smoke were found to have the greatest risk of contracting the disease, but exposure to sunlight, notably ultraviolet B (UVB) light, also seems to have an impact, according to a report published in the Journal of Epidemiology and Community Health.
Researchers looked at the association between latitude, exposure to UVB light, and rates of lung cancer according to age in 111 countries across several continents.
The amount of UVB light increases as you move closer to the equator, and analyses showed lung cancer rates are highest in the countries furthest away from the equator, and lowest in those nearest.
For men, the prevalence of smoking was associated with higher lung cancer rates, with greater exposure to UVB light associated with lower rates.
Among women, cigarette smoking, total cloud cover, and airborne aerosols were associated with higher rates, and greater exposure to UVB light was associated with lower rates.
The authors of the report concluded that while cigarette smoking is the main cause of lung cancer, greater UVB exposure may reduce the incidence of the disease.