Long-term Trend in Sunscreen Use among Beachgoers in Denmark

Abstract

This observational study examined the trend from the 1990s to 2016 of sunscreen use, sun protection factor (SPF) and quantity of sunscreen applied amongst beachgoers in Denmark. In 1997, 1998, 1999 and 2016, a total of 1,306 beachgoers were asked if they had used sunscreen on that day and, if so, which SPF. In 1992 and 2016 another 143 beachgoers had their sunscreen bottles weighed before and after application. The frequency of sunscreen use among women increased from 45% in 1997 to 78% in 2016, while the frequency of use among men increased from 39% to 49%. For both sexes the median SPF increased, on average, by one unit per year, from SPF 5 in 1997 to SPF 20 in 2016. The quantity of sunscreen applied increased from 0.48 mg/cm2 in 1992 to 0.57 mg/cm2 in 2016. Thus, the frequency of sunscreen use, the SPF, and the quantity of sunscreen applied have increased in the recent decades.

Sunscreen use optimized by two consecutive applications

“…The standard curve shows the best sensitivity in quantities of sunscreen ranging from 0 to 1.0 mg/cm 2 . Fortunately these quantities are those used in real-life settings [ 3 ].…”

“…To avoid sunburn and skin cancer it is recommended to protect the skin from solar ultraviolet radiation (UVR) by seeking shade, avoiding sun exposure around noon, wearing clothes, and applying sunscreen [ 1 , 2 ]. Sunscreen application is a commonly followed recommendation [ 3 ]. Studies have documented that sunscreen users often gain insufficient protection and get sunburned after a single application, especially on holidays in sunny locations [ 4 , 5 ].…”

“…In connection with another study [ 3 ] we asked 117 visitors leaving beaches in Denmark if they had used sunscreen that day and if they had applied sunscreen once or more than once. Fifty percent reported to have used sunscreen on that particular day.…”

Photoprotection by sunscreen depends on time spent on application

“…After the first application, the average quantity of sunscreen applied was 0.71 mg/cm 2 , which is at the high end compared to previous findings. 7 This may be explained by more sunscreen and more time spent on application in the laboratory environment than would have been the case in real life.…”

“…[1][2][3] To be effective, sunscreen must be applied in a adequate quantity on all exposed body sites, and studies have documented that sunscreen users often gain insufficient protection resulting in sunburn. [4][5][6] When determining the sunscreen protection factor (SPF), a quantity of 2 mg/cm 2 is applied, but in real life only, 0.5-1.0 mg/cm 2 is used, 7 which may be one of the explanations for inadequate protection. 8 Another reason could be that certain exposed skin areas are left without sunscreen.…”