Sunlight accessibility indoors and mental health: evidence from a social housing community in Glasgow, Scotland

This paper presents preliminary findings of a pilot study undertaken to investigate if access to sunlight in the home may be a factor influencing psychological health of residents of social housing in Glasgow. The study also sought to investigate underlying pathways and mechanisms, in particular the bactericidal effect of sunlight. The study was undertaken in the Shawlands area of Glasgow in October 2012. Forty residents living in four tower blocks were recruited: 24 male and 16 female, 21-70 years. Psychological health was assessed using the Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS) and the General Health Questionnaire (GHQ12). Sunlight accessibility indoors was defined using two metrics: Sunlight Aperture Opportunity (SAO) and Sunlight Surface Opportunity (SSO), m2 hr yr-1, with modelling undertaken using Integrated Environmental Solutions Virtual Environment. WEMWBS was positively associated with living room SSO with occlusion from curtains and blinds taken into account, SSOCB (rs = .322, p = .043), and living room carpet bacteria was marginally significant (rs = .300, p = .06). For a subgroup of individuals who spent > 2 h / day in their living room between 9am ? 6pm (n = 18), the relationship between WEMWBS and living room SSOCB was stronger than for the sample as a whole (SSOCB rs = .733, p = .001), and living room SSOCB accounted for 40% of variance in WEMWBS (adj. R2 = .367, p = .005). GHQ12 was not associated with any sunlight metrics but there was a significant inverse association with living room carpet bacteria (rs = -.402, p = .010), accounting for 13% of variance in GHQ12 (adj. R2 = .106, p = .023). These findings indicate that access to sunlight in the home may be an important factor influencing the psychological health of residents of social housing in disadvantaged areas of Glasgow. Further research is warranted.