Public Health Challenges in Sun Protection

Sunscreens protect against skin cancer and other harmful effects of solar ultraviolet radiation (UVR). Epidemiologic and public health surveys often rely on self-reported sunscreen use to estimate sun exposure and avoidance, but questions remain about the validity of self-reports. Benzophenone-3 (BP-3), a common sunscreen ingredient, can be detected in the urine. Prior studies suggest that BP-3 concentrations increase after application of sunscreen.

The goal of this study was to assess the validity of self-reported frequency of sunscreen use in relation to urinary BP-3 concentrations in a representative sample of the general US population, including in sub-groups defined by age, sex and race/ethnicity.

To assess the relationship between categorical self-reported sunscreen use and creatinine-corrected urinary BP-3 concentrations, we conducted a linear regression adjusted for age, sex, race/ethnicity, six-month time period, body mass index, education, and sun avoidance behaviors. We tested for effect modification by age, sex, ethnicity and time period of measurement using multiplicative interaction terms and a F test.

BP-3 was positively associated with self-reported frequency of sunscreen use across all ages, sexes, race/ethnicities, and time periods. Crude and multivariate adjusted models were all statistically significant. R-square was relatively low for all models, ranging from 0.15 to 0.43.

Urinary BP-3 is positively associated with self-reported frequency of sunscreen use in the general US population, even in groups with overall low sunscreen use. These results suggest that self-report is a valid, although weak, way of assessing relative frequencies of sunscreen usage in a population-based study.

Benzophenone (BP)-type UV filters are commonly used in our daily life. 2-hydroxy-4-methoxy benzophenone (BP-3), 4-hydroxy benzophenone (4-HBP), 2,4-dihydroxy benzophenone (BP-1), 2,2′,4,4′-tetrahydroxy benzophenone (BP-2) and 2,2′-dihydroxy-4-methoxy benzophenone (BP-8) were measured in urine samples from Chinese young adults. The results indicated that Chinese young adults were widely exposed to BP-3, BP-1, and 4-HBP, with the median concentrations of 0.55, 0.21, and 0.08 ng/mL, respectively. No significant difference was found between males and females, between urban and rural population. The correlations between urinary concentrations provided important indications for sources and metabolic pathways of target compounds. The estimated daily excretion doses of BP-3, 4-HBP, BP-1, BP-2 and BP-8 were 27.2, 2.24, 5.86, 0.76 and 0.30 ng/kg-bw/day, respectively. The ratio of exposure to excretion must be considered for the exposure assessment with chemicals based on urine measurement. This is the first nationwide study on BP-derivatives with young adults in China.

Los niños son uno de los grupos de la población en los que debe extremarse la fotoprotección. En primer lugar, porque desarrollan una actividad al aire libre mucho más importante que los adultos. En segundo lugar, porque el principal factor de riesgo del cáncer de piel es la radiación ultravioleta, sobre todo aquella radiación producida durante la infancia. La disminución de la exposición solar en los niños puede disminuir potencialmente la incidencia del cáncer cutáneo.

La fotoprotección incluye todas aquellas medidas que se pueden instaurar para proteger a la piel de la agresión producida por la exposición solar, como las conductas de evitación solar, la protección con ropas, gorros y gafas solares y el uso de fotoprotectores.

Es necesario dar a conocer la importancia de la fotoprotección entre los padres y, sobre todo, entre los niños mediante campañas educativas que incrementen el conocimiento de las medidas fotoprotectoras y que favorezcan cambios en el comportamiento respecto de la exposición solar. En esta labor educativa los dermatólogos y los pediatras ocupan un papel fundamental.

En esta revisión se actualizan los conocimientos más recientes en fotoprotección infantil, las novedades en fotoprotectores y las campañas más recientes sobre educación solar.

Children are one of the population groups in which the photo-protection must be maximised. Firstly, because they take part in outdoor activities more often than adults. Secondly, because the principal risk factor for all types of skin cancer is ultraviolet radiation, and in particular, cumulative exposure during childhood. Hence, decreasing exposure to ultraviolet radiation in childhood has the potential to significantly lower the incidence of most forms of skin cancer.

Photoprotection includes behavioural measures to protect the skin from sun exposure, e.g. sun protective clothes, hats, sunglasses, and sunscreens. It is necessary to provide information on aphotoprotection to parents, and, above all, to children, using educational campaigns to increase knowledge of photoprotection to help change attitudes towards sun exposure. Dermatologists and Paediatricians play a essential role in this educational work.

In this article we review the latest information regarding paediatric sun protection, the new sunscreens, and the recent sun protection educational programs.

UV radiation is the main etiological agent of most types of skin cancer and a key factor responsible for photoaging. Photoprotection is thus critical to avoid these undesired effects. Sunscreens rank among the best photoprotective measures. Sunscreens are the main components of lotions and creams used to prevent UV-induced damage or to ameliorate its harmful effects. There are 3 types of sunscreens: physical photon blockers, antioxidants, and stimulators of repairing mechanisms. This review summarizes current topics in the development of sunscreens, with special emphasis on substances of natural origin bearing photoscreening, antioxidant, or repairing properties. The characterization of different parameters to evaluate the effects of sunscreens, such as the sunscreen protection factor, is discussed. Finally, the effect of public awareness and public health campaigns are also reviewed.

Benzophenone (BP) derivatives, BP1 (2,4-dihydroxybenzophenone), BP2 (2,2′,4,4′-tetrahydroxybenzophenone), BP3 (2-hydroxy-4-methoxybenzophenone), and THB (2,4,4′-trihydroxybenzophenone) are UV-absorbing chemicals widely used in pharmaceutical, cosmetics, and industrial applications, such as topical sunscreens in lotions and hair sprays to protect skin and hair from UV irradiation. Studies on their endocrine disrupting properties have mostly focused on their interaction with human estrogen receptor alpha (hERα), and there has been no comprehensive analysis of their potency in a system allowing comparison between hERα and hERβ activities. The objective of this study was to provide a comprehensive ER activation profile of BP derivatives using ER from human and fish origin in a battery of in vitro tests, i.e., competitive binding, reporter gene based assays, vitellogenin (Vtg) induction in isolated rainbow trout hepatocytes, and proliferation based assays. The ability to induce human androgen receptor (hAR)-mediated reporter gene expression was also examined. All BP derivatives tested except BP3 were full hERα and hERβ agonists (BP2 > THB > BP1) and displayed a stronger activation of hERβ compared with hERα, the opposite effect to that of estradiol (E₂). Unlike E₂, BPs were more active in rainbow trout ERα (rtERα) than in hERα assay. All four BP derivatives showed anti-androgenic activity (THB > BP2 > BP1 > BP3). Overall, the observed anti-androgenic potencies of BP derivatives, together with their proposed greater effect on ERβ versus ERα activation, support further investigation of their role as endocrine disrupters in humans and wildlife.