A Quantitative General Population Job Exposure Matrix for Occupational Daytime Light Exposure

Anne Vested*, Vivi Schlünssen, Alex Burdorf, Johan Hviid Andersen, Jens Christoffersen, Stine Daugaard, Esben M. Flachs, Anne Helene Garde, Åse Marie Hansen, Jakob Markvart, Susan Peters, Zara Stokholm, Jesper M. Vestergaard, Helene T. Vistisen, Henrik Albert Kolstad

*Corresponding author

Research output: Contribution to journalJournal articleResearchpeer-review

3 Citations (Scopus)


High daytime light levels may reduce the risk of affective disorders. Outdoor workers are during daytime exposed to much higher light intensities than indoor workers. A way to study daytime light exposure and disease on a large scale is by use of a general population job exposure matrix (JEM) combined with national employment and health data. The objective of this study was to develop a JEM applicable for epidemiological studies of exposure response between daytime light exposure, affective disorders, and other health effects by combining expert scores and light measurements. We measured light intensity during daytime work hours 06:00–17:59 for 1–7 days with Philips Actiwatch Spectrum® light recorders (Actiwatch) among 695 workers representing 71 different jobs. Jobs were coded into DISCO-88, the Danish version of the International Standard Classification of Occupations 1988. Daytime light measurements were collected all year round in Denmark (55–56°N). Arithmetic mean white light intensity (lux) was calculated for each hour of observation (n = 15,272), natural log-transformed, and used as the dependent variable in mixed effects linear regression models. Three experts rated probability and duration of outdoor work for all 372 jobs within DISCO-88. Their ratings were used to construct an expert score that was included together with month of the year and hour of the day as fixed effects in the model. Job, industry nested within job, and worker were included as random effects. The model estimated daytime light intensity levels specific for hour of the day and month of the year for all jobs with a DISCO-88 code in Denmark. The fixed effects explained 37% of the total variance: 83% of the between-jobs variance, 57% of the between industries nested in jobs variance, 43% of the between-workers variance, and 15% of the within-worker variance. Modeled daytime light intensity showed a monotonic increase with increasing expert score and a 30-fold ratio between the highest and lowest exposed jobs. Building construction laborers were based on the JEM estimates among the highest and medical equipment operators among the lowest exposed. This is the first quantitative JEM of daytime light exposure and will be used in epidemiological studies of affective disorders and other health effects potentially associated with light exposure.
Original languageEnglish
JournalAnnals of Work Exposures and Health
Issue number6
Pages (from-to)666-678
Number of pages13
Publication statusPublished - 24 Jul 2019


  • epidemiology
  • job exposure matrix
  • light exposure
  • mixed effects model
  • occupational


Lux@r: Helbredskonsekvenser af lysmiljøet ved indendørsarbejde og natarbejde

Markvart, J., Johnsen, K., Logadóttir, Á., Kolstad, H. A., Tilma Vistisen, H., Garde, A. H., Christoffersen, J. & Hesselvang, L.


Project: Research

Research Output

  • 3 Citations
  • 3 Journal article
  • 1 Net publication - Internet publication

Light Exposure during Days with Night, Outdoor, and Indoor Work

Daugaard, S., Markvart, J., Bonde, J. P., Christoffersen, J., Garde, A. H., Hansen, Å. M., Schlünssen, V., Vestergaard, J. M., Vistisen, H. T. & Kolstad, H. A., 24 Jul 2019, In : Annals of Work Exposures and Health. 63, 6, p. 651-665 15 p.

Research output: Contribution to journalJournal articleResearchpeer-review

  • 4 Citations (Scopus)

    Night work, light exposure, and melatonin on work days and days off

    Pedersen, S. D., Garde, A. H., Bonde, J. P. E., Christoffersen, J., Hansen, Å. M., Markvart, J., Schlünssen, V., Skene, D., Tilma Vistisen, H. & Kolstad, H. A., 2017, In : Chronobiology International. 34, 7, p. 942-955

    Research output: Contribution to journalJournal articleResearchpeer-review

    12 Citations (Scopus)

    Light Exposure Assessment of Danish Indoor, outdoor and Night-Shift Workers: Experiences from a field study

    Markvart, J., 2016

    Research output: Other contributionNet publication - Internet publicationCommunication

    Cite this

    Vested, A., Schlünssen, V., Burdorf, A., Andersen, J. H., Christoffersen, J., Daugaard, S., Flachs, E. M., Garde, A. H., Hansen, Å. M., Markvart, J., Peters, S., Stokholm, Z., Vestergaard, J. M., Vistisen, H. T., & Kolstad, H. A. (2019). A Quantitative General Population Job Exposure Matrix for Occupational Daytime Light Exposure. Annals of Work Exposures and Health, 63(6), 666-678. https://doi.org/10.1093/annweh/wxz031