【摘要】 [目的]研究低剂量使用防晒化妆品和不同涂布方式的日光防护效果,为指导消费者合理使用防晒化妆品提供科学依据。[方法]选择60名受试者,随机分为涂布组和对照组。涂布组在手背低剂量(0.5 mg/cm2)使用防晒化妆品,对照组不使用防晒化妆品。另外涂布组的左右手背分别采用双次涂布和多次涂布两种不同的使用方式。受试者在连续9 d的军训期间每天接受阳光紫外线照射6 h(上午8:00—11:00、下午14:00—17:00)。通过观察日光暴露前后手背皮肤颜色的变化,评价防晒化妆品的防晒效果。肤色的测量采用色差分析仪。[结果]与各自日光暴露前相比,两组受试者暴露后的手背皮肤颜色指标亮度L值均降低(53.95~54.86vs56.75~58.64),绿红色饱和度a(10.86~11.59vs9.44~10.20)和蓝黄色饱和度b(20.31~21.09vs19.16~19.74)值均升高(P<0.05);日光暴露前后,涂布组受试者左右手背肤色的立体变化指标色差△E均小于对照组[(3.31±1.91),(3.17±1.82)vs(5.63±2.37),(5.74±2.56)](均P<0.05),多次涂布手背肤色的立体变化指标色差△E与双次涂布的没有差异(P>0.05)。[结论]与不使用防晒化妆品相比,低剂量使用防晒化妆品仅能减缓但无法避免肤色向黑红黄方向变化。在低剂量使用防晒化妆品的情况下,增加涂布次数没有增强防晒化妆品的防护效果。更多还原

【Abstract】 [Objective] To assess the protective effect of low-dose sunscreen and different applying methods,and provide a scientific basis for guiding customer sunscreen usage.[Methods] A total of 60 subjects were randomly divided into control group and sunscreen group.The sunscreen group applied sunscreen at a low dose(0.5 mg/cm~2) on the back of hands and the control group did not.In addition,the sunscreen group was treated with spreading sunscreen twice and six times over a day on the back of left hand and right hand respectively.The subjects were exposed to sunlight for six hours per day(8:00-11:00,14:00-17:00) during nine continuous days of military training.The skin color changes induced by sunlight exposure were evaluated in the volunteers with a tristimulus colorimeter.[Results] Both groups showed reduced lightness(L)(after:53.95-54.86,before:56.75-58.64)(P<0.05) as well as increased green-red saturation(a)(after:10.86-11.59,before:9.44-10.20) and blue-yellow saturation(b)(after:20.31-21.09,before:19.16-19.74)(P<0.05) after sunlight exposure.The color differences(△E) of left and right hands in the sunscreen group(left:3.31±1.91,right:3.17±1.82) were lower than those in the control group(left:5.63±2.37,right:5.74±2.56)(Ps<0.05),and no difference was observed between the hands treated with twice and six times of sunscreen(P > 0.05).[Conclusion] Using low-dose sunscreen can only slow down but cannot avoid the change of skin color to black,red,and yellow compared to using no sunscreen products.In the case of using low-dose sunscreen,increasing application times does not enhance its protective effect.更多还原