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.

Light enables us to see and perceive our environment but it also initiates effects beyond vision, such as alertness. Literature describes that at least six factors are relevant for initiating effects beyond vision. The exact relationship between these factors and alertness is not yet fully understood. In the current field study, personal lighting conditions of 62 Dutch office workers (aged 49.7 ± 11.4 years) were continuously measured and simultaneously self-reported activities and locations during the day were gathered via diaries. Each office worker participated 10 working days in spring 2017. Personal lighting conditions were interpreted based on four of the six factors (light quantity, spectrum, timing, and duration of light exposure). Large individual differences were found for the daily luminous exposures, illuminances, correlated colour temperatures, and irradiances measured with the blue sensor area of the dosimeter. The average illuminance (over all participants and all days) over the course of the day peaked three times. The analysis of the duration of light exposure demonstrated that the participants were on average only exposed to an illuminance above 1000 lx for 72 minutes per day. The interpretation of personal lighting conditions based on the four factors provides essential information since all of these factors may be relevant for initiating effects beyond vision. The findings in the current paper give first in-depth insight in the possibilities to interpret personal lighting conditions of office workers.

Daytime light levels are important for human physiology. Office workers spend most of their daytime inside buildings where it is unclear whether they receive healthy light levels. A recent publication presented recommendations for the minimum daytime light level for optimal human health, expressed in melanopic equivalent daylight illuminance (EDI). The current paper assesses whether this recommended daytime light level is achieved by office workers through a meta-analysis of personal light levels of office workers, obtained from light-dosimetry field studies. From our literature search, we identified nine eligible papers. These papers comprised data from studies in one or multiple office buildings, over one or more seasons, from 1 to 62 participants, and for 19 to 564 workdays. After analysing the data, we found that in none of the offices the recommended minimum light level of 250 melanopic EDI was met for the entire day. Only 1 out of 6 median and 6 out of 13 mean reported personal light levels were above this recommended value. Unfortunately, these conclusions are less groundbreaking than we hoped for, due to large differences between study protocols. This resulted in a large variety of (unreported) study characteristics (i.e. light data, light-dosimeter, participant, building and environment) which complicated a fair comparison between the different studies. To facilitate meta-analyses of light-dosimetry field studies, we introduce recommendations for data collection and reporting in light-dosimetry field studies. We based these recommendations on the gaps identified from our meta-analysis, supplemented by recommendations from other papers.

BACKGROUND: The non-image-forming effects of luminous radiation on people with intellectual disabilities or dementia received attention from researchers. Such studies, however, have generally been conducted using disparate methodologies which precludes generalization and reproducibility. OBJECTIVE: The aim of this study was to determine the practical applicability of measurement devices for studies investigating non-image-forming effects of luminous radiation, specifically for people with intellectual disabilities or dementia. METHODS: In three experiments, ten cognitive impaired people and thirty-nine unaffected subjects participated by wearing one or more portable devices. Six devices were assessed in total. Measurement data was accompanied with user experiences obtained from questionnaires, interviews and observations in order to assess the devices on practical and comfort issues. RESULTS: On average, the devices worn by the cognitive impaired subjects were not experienced as annoying or irritating. No significant differences are found between genders and for one of the portable devices significantly less annoyance was reported by the cognitive impaired participants compared to the unaffected group of participants. INNOVATIVE SOLUTION: The three phases of the research process in towards measuring personal luminous exposures are: selection of the most suitable portable device, application of the assessment method, and the application of the device in the (pilot) study. CONCLUSIONS: However, the findings of this study suggest that inaccuracies potentially caused by practical and comfort issues associated with the portable devices need to be considered.