BACKGROUND/ PURPOSE: The persistence of sunscreens during a day with physical activity and bathing is often debated. We wished to examine the durability of the protection achieved by one sunscreen application. METHODS: Seven areas were marked on the back of 24 volunteers. One area was phototested to determine UV sensitivity. Six areas were treated with either an organic or an inorganic sunscreen (2 mg/cm2). The participants performed physical activities, were exposed to a hot environment and bathing during 8 h and were phototested with ultraviolet-B (UVB) radiation 30 min, 4 and 8 h after sunscreen application. The minimal erythema dose (MED) was determined 24 h after irradiation. The sun protection factor (SPF) was calculated, as MED on protected skin/MED on unprotected skin. RESULTS: The SPFs of the inorganic and organic sunscreen, respectively, were reduced by 38% and 41% after 4 h and by 55% and 58% after 8 h. CONCLUSION: One application of either an inorganic or an organic sunscreen reduced the erythema caused by UVB during a day with physical activity and bathing. After 8 h the sunscreens still provided approximately 43% of the initial protective effect. This might simulate what happens during a day at the beach.
BACKGROUND/ PURPOSE: The persistence of sunscreens during a day with physical activity and bathing is often debated. We wished to examine the durability of the protection achieved by one sunscreen application. METHODS: Seven areas were marked on the back of 24 volunteers. One area was phototested to determine UV sensitivity. Six areas were treated with either an organic or an inorganic sunscreen (2 mg/cm2). The participants performed physical activities, were exposed to a hot environment and bathing during 8 h and were phototested with ultraviolet-B (UVB) radiation 30 min, 4 and 8 h after sunscreen application. The minimal erythema dose (MED) was determined 24 h after irradiation. The sun protection factor (SPF) was calculated, as MED on protected skin/MED on unprotected skin. RESULTS: The SPFs of the inorganic and organic sunscreen, respectively, were reduced by 38% and 41% after 4 h and by 55% and 58% after 8 h. CONCLUSION: One application of either an inorganic or an organic sunscreen reduced the erythema caused by UVB during a day with physical activity and bathing. After 8 h the sunscreens still provided approximately 43% of the initial protective effect. This might simulate what happens during a day at the beach.
Authors: Sérgio Schalka; Denise Steiner; Flávia Naranjo Ravelli; Tatiana Steiner; Aripuanã Cobério Terena; Carolina Reato Marçon; Eloisa Leis Ayres; Flávia Alvim Sant'anna Addor; Helio Amante Miot; Humberto Ponzio; Ida Duarte; Jane Neffá; José Antônio Jabur da Cunha; Juliana Catucci Boza; Luciana de Paula Samorano; Marcelo de Paula Corrêa; Marcus Maia; Nilton Nasser; Olga Maria Rodrigues Ribeiro Leite; Otávio Sergio Lopes; Pedro Dantas Oliveira; Renata Leal Bregunci Meyer; Tânia Cestari; Vitor Manoel Silva dos Reis; Vitória Regina Pedreira de Almeida Rego Journal: An Bras Dermatol Date: 2014 Nov-Dec Impact factor: 1.896
Authors: R P E Sarkany; M Canfield; M Morgan; L Foster; K Johnstone; K Sainsbury; V Araujo-Soares; H C Wulf; J Weinman; J Walburn; S Norton Journal: Br J Dermatol Date: 2022-02-24 Impact factor: 11.113
Authors: Marc Rocholl; Patricia Weinert; Stephan Bielfeldt; Sabrina Laing; Klaus Peter Wilhelm; Claas Ulrich; Swen Malte John Journal: J Occup Med Toxicol Date: 2021-07-05 Impact factor: 2.646