J. van Duijnhoven

Systematic review on the interaction between office light conditions and occupational health: Elucidating gaps and methodological issues:

Purpose The International Commission on Illumination (CIE) recommends researchers to investigate a wide variety of behavioural and health outcomes. However, researchers often investigate only a part of occupational health (OH) in relation to light. A literature study (2002–2017) regarding the relationship between office lighting conditions and OH was performed to identify gaps and methodological issues. Method The OH outcomes investigated in this paper were grouped according to the International Classification of Diseases and analysed per category: physical and physiological health, mental health, eye health, sleep parameters and visual comfort. Results Findings from the literature study (20 eligible papers) showed that all OH aspects were mostly but not exclusively measured subjectively. Furthermore, most studies investigated only a fraction of office lighting parameters and OH aspects. Conclusions It seems that Correlated Colour Temperature (CCT) and illuminance mainly correlate with OH. However, this may also be explained by gaps and methodological issues in studies described in eligible papers. Based on the literature study, an overview was composed elucidating gaps and methodological issues of office lighting and OH studies. It can be used to design and target the purpose of light and health research.

Personal Lighting Conditions to Obtain More Evidence in Light Effect Studies

Research demonstrated a large variety regarding effects of light (e.g. health, performance, or comfort effects). Since human health is related to each individual separately, the lighting conditions around these individuals should be analysed individually as well. This paper provides, based on a literature study, an overview identifying the currently used methodologies for measuring lighting conditions in light effect studies. 22 eligible articles were analysed and this resulted in two overview tables regarding the light measurement methodologies. In 70% of the papers, no measurement details were reported. In addition, light measurements were often averaged over time (in 84% of the papers) or location level (in 32% of the papers) whereas it is recommended to use continuous personal lighting conditions when light effects are being investigated. Conclusions drawn in light effect studies based on personal lighting conditions may be more trusting and valuable to be used as input for an effect-driven lighting control system.

An unobtrusive practical method to derive individual's lighting conditions in office environments

The benefits of light in offices beyond enabling visual tasks have been demonstrated in former studies. Light positively influences outcome measures such as humans health, wellbeing, visual comfort, motivation, and environmental satisfaction. In order to measure the effects of light on the individual outcome measures, it is of high importance to correctly measure lighting conditions in realistic environments per individual. This paper describes a six-step practical method to derive lighting conditions for all work places in an office building based on continuous reference measurements. The method proposed in this paper allows the shift from laboratory studies to field studies so that the real effect of office lighting can be investigated simultaneously while the office worker is doing his or her real work.