Cutaneous Cardiovascular And Thermoregulatory Responses To Ultraviolet Radiation Exposure And Sunscreen Application
Open Access
- Author:
- Fisher, Kathleen
- Graduate Program:
- Kinesiology
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- October 03, 2023
- Committee Members:
- William Lawrence Kenney, Jr., Thesis Advisor/Co-Advisor
Lacy Marie Alexander, Committee Member
Jonathan Dingwell, Professor in Charge/Director of Graduate Studies
David E Conroy, Committee Member - Keywords:
- Ultraviolet Radiation
sunscreen
thermoregulation
skin pigmentation
athletes - Abstract:
- Exposure to UVR is associated with deleterious health effects such as cutaneous vascular dysfunction, DNA damage, and skin cancer. Outdoor athletes routinely eschew using sunscreen as protection from UVR due to perceptions that sunscreen may impair thermoregulatory heat loss, although, past studies examining the impact of sunscreen application on thermoregulatory responses have been equivocal. Additionally, while acute exposure to UVR has been found to attenuate nitric oxide (NO)-dependent vasodilation, it is unknown how seasonal UVR exposure impacts cutaneous microvascular function. Therefore, it is necessary to understand the impacts of UVR and sunscreen application on vascular health and thermoregulatory responses, respectively, so that outdoor recreationists can make informed decisions regarding sun safety. This thesis comprises two empirical studies investigating (1) the impact of within-limb variation in skin pigmentation on cutaneous microvascular function and (2) the impact of sunscreen application on integrative thermoregulatory responses. The findings of the first study conclude that within-limb differences in skin pigmentation secondary to UVR exposure do not alter NO-dependent cutaneous vasodilation. The findings of the second study suggest that the combinations of temperature and humidity at which heat stress becomes uncompensable are not altered by the application of either chemical or mineral sunscreen. At the highest level of compensable heat stress, sunscreen application did not alter any thermoregulatory responses of interest (body temperatures, heart rate, sweating, sweating efficiency, evaporative efficiency, etc.). Therefore, perceived adverse thermoregulatory effects should not dissuade outdoor athletes from utilizing sunscreen. Together these studies can provide information to outdoor athletes and recreationists so that informed decision about adequate sun protection can be made.