Petersen Bibi, Wulf Hans Christian
Department of Dermatological Research, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark.
Photodermatol Photoimmunol Photomed. 2014 Apr-Jun;30(2-3):96-101. doi: 10.1111/phpp.12099. Epub 2014 Jan 6.
We present research on sunscreen use with possible pitfalls and discuss theory vs. reality. A literature review in PubMed was conducted using the terms 'sunscreen application', 'sunscreen use' and 'sun protection factor'. The sun protection factor (SPF) of sunscreens are tested using a thickness of 2 mg/cm(2) , but investigations show that sunscreen under natural conditions is applied insufficiently with amounts about 0.39 to 1.0 mg/cm(2) , which decreases the protection factor considerably. It has been shown that early reapplication or use of very high SPF (70-100) may partly compensate for the discrepancy between the amounts of sunscreen applied during testing and in reality, and that sunscreen application can be improved by education of consumers. Missing areas and ultraviolet radiation exposure before sunscreen application are other pitfalls that reduce the protective effect of sunscreens considerably. Current sunscreen labelling overrates the protective effect of a given sunscreen when the reality of sunscreen use is taken into account. This may possibly mislead consumers to feel it is safe to extend sun exposure. Alternatively to educating people to use large amounts of sunscreen, we suggest a simple teaching strategy: (1) Apply before sun exposure and (2) Reapply once within 1 h.
我们展示了关于防晒霜使用的潜在问题的研究，并讨论了理论与现实。在PubMed上使用“防晒霜涂抹”“防晒霜使用”和“防晒系数”等术语进行了文献综述。防晒霜的防晒系数（SPF）是在2毫克/平方厘米的厚度下进行测试的，但调查显示，在自然条件下，防晒霜的涂抹量不足，约为0.39至1.0毫克/平方厘米，这大大降低了保护系数。研究表明，早期重新涂抹或使用非常高的SPF（70 - 100）可能部分弥补测试期间和实际使用中防晒霜涂抹量之间的差异，并且通过对消费者的教育可以改善防晒霜的涂抹情况。在涂抹防晒霜之前存在的未涂抹区域和紫外线暴露是其他会大大降低防晒霜保护效果的陷阱。当考虑到防晒霜使用的实际情况时，当前的防晒霜标签高估了给定防晒霜的保护效果。这可能会误导消费者认为延长日晒时间是安全的。除了教育人们使用大量防晒霜之外，我们建议一种简单的教学策略：（1）在日晒前涂抹，（2）在1小时内重新涂抹一次。
