Although umbrellas obstruct direct sunlight, they do not prevent exposure from diffuse or reflected UV rays that can also cause sunburn and skin damage.
The increased risk of skin cancer resulting from sun exposure is widely recognized in modern generations. As a result, protective measures such as use of sunscreen, protective clothing, and general avoidance of excessive time in the sun, are now common practices.
Although it is clear that taking shelter in the shade reduces sun exposure, data suggests that shade alone may not be sufficient to fully protect from harmful UV rays. In fact, even indirect sun exposure – from rays that are diffused by particles in the atmosphere or reflected off the ground or other objects – can cause skin damage.
A study recently published in JAMA Dermatology sought to make a head-to-head comparison of the effectiveness of shade versus sunscreen in protecting individuals from sunburn. The study involved 81 participants in Lake Lewisville, Texas, all of whom who spent 3 ½ hours on a sunny beach at mid-day. Half of the participants applied sunscreen with an SPF rating of 100; the other half sheltered under a sun umbrella. All were evaluated for sunburn on several body sites (face, back of neck, upper chest, arms and legs) between 22 and 24 hours after exposure.
Results showed that while neither approach completely eliminated the possibility of sunburn, rates of sunburn were noticeably higher in the umbrella group. Taking all body sites into account, there were 142 incidents of sunburn in the umbrella group, compared with only 17 in the sunscreen group. In addition, 32 of the umbrella group participants experienced erythema (a rash-like reddening of the skin) in at least one location, versus only 10 cases in the sunscreen group.
Authors of the study advise that using a beach umbrella alone should not be relied on to protect against skin damage from harmful UV rays. They suggest that the best strategy may be a combination of sunscreen and shade protection.
Written By: Linda Jensen