Positive impact of sunlight exposure on mental health in a naval population.

Naval shipboard operations impose numerous environmental and occupational stressors, which can adversely affect mental and physical health outcomes. Moreover, this operational setting also complicates the implementation of countermeasures to protect personnel from these stressors. Thus, any easily accessible or modifiable protective factors should be explored further for their potential to support the health of military personnel. Daily sunlight exposure is one such factor that has demonstrated positive effects on health outcomes. For the current study, sunlight exposure and self-reported health outcomes were explored in a large population of U.S. Navy personnel (N > 11,000). Mediator analyses examined the relationship between mental and physical health while controlling for key confounding variables such as morale and exercise. Although the overall regression models indicated only a slight impact on physical health, sunlight exposure had a significant direct effect on mental health even while controlling for the mediating influence of morale. Sunlight exposure also had an impact on morale and an indirect influence on mental health through morale. Additional analyses further supported the possible mental health benefits of sunlight exposure even while accounting for occupational differences. The results suggest that prescribed sunlight exposure aboard ships could be used to promote positive mental health during naval operations.