Improving Photoprotection Attitudes in the Tropics: Sunburn vs Vitamin D

Abstract

The ultraviolet radiation of type B (the UVB) stimulates both the production of vitamin D (VD) and the incorporation of erythema dose (ED). The UVA also contributes to ED. The turning point between the benefit of producing VD and the harm of incorporating ED cannot be determined easily. However, the casual behavior regarding the exposure to the Sun can be changed in order to improve the protoprotection attitudes and create a trend towards benefit. In the case, people living in the low latitudes should exposure themselves to the Sun for a determined time interval within the noon time and avoid the Sun in other periods. This would produce an adequate amount of VD through the VD dose (207-214 J m(-2)) against minimum ED (≈105 J m(-2)) for skin type II. For it, unprotected forearms and hands must be exposed to the noon Sun (cloudless) for 11 min (winter) and 5 min (summer). The exposure at other times different from noon can represent increases of up to 24% in ED and up to 12 times in the time interval to be in the Sun in relation to the minimum amounts of both ED and time interval at noon.

Daily Maximum Erythemal Dose Rates in the Tropics

“…In fact, it is likely that daily exposures to increments of a few tens of percentage in EDR, as seen in Figures and owing to the scattering of solar radiation from clouds, can potentially produce significant harmful doses in the long‐term of years . In the short‐term of a few minutes, it could induce erythema in fair‐skinned people . For instance, the 45% surplus of the DEC292009 EDR max to the reference EDR max on JAN022010 correspond to an augmentation of 0.151 W m −2 (UVI = 6) in the incidence of erythemal UVR.…”

1,2‐Diketones as photoinitiators of both cationic and free‐radical photopolymerization under UV (392 nm) or Blue (455 nm) LEDs

“…As CQ is a 1,2‐ketone‐based PI that is sensitive to blue light, other low‐cost 1,2‐ketones based systems may also capable to initiate photopolymerization under visible light. In fact, there are reports of photochemical studies on 1,2‐ketones such as acenaphthenequinone ( ANPQ ), aceanthrenequinone ( AATQ ), and 9,10‐phenanthrenequinone ( PANQ ) . These compounds can interact with other molecules, such as hydrogen donors, through electron transfer reactions during light irradiation.…”

The Impact of Courtyard and Street Canyon Surroundings on Global Illuminance and Estimated UV Index in the Tropics

“…'sunbathing') for a short period, particularly in the morning time. The ultraviolet (UV) radiation of the sunlight on one hand stimulates the production of vitamin D, which is important in maintaining healthful bones, and may help the body in suppressing the risk of development of various diseases such as cancer, diabetes, arthritis, and others [1][2][3][4][5]. While there is still no strong evidence on whether sunlight exposure is effective in lowering the risk of COVID-19 infection; on the other hand, it is clear that excessive and prolonged exposure of sunlight on human skin may lead to various harmful effects, such as sunburn, skin cancer, skin ageing, and many others [5,6].…”