Morning boost on individuals' psychophysiological wellbeing indicators with supportive, dynamic lighting in windowless open-plan workplace in Malaysia

RatnaKala Sithravel; Rahinah Ibrahim; Munn Sann Lye; Enoch Kumar Perimal; Normala Ibrahim; Nur Dalilah Dahlan

doi:10.1371/journal.pone.0207488

Morning boost on individuals' psychophysiological wellbeing indicators with supportive, dynamic lighting in windowless open-plan workplace in Malaysia

PLoS One. 2018 Nov 29;13(11):e0207488. doi: 10.1371/journal.pone.0207488. eCollection 2018.

Authors

RatnaKala Sithravel¹, Rahinah Ibrahim¹, Munn Sann Lye², Enoch Kumar Perimal³, Normala Ibrahim⁴, Nur Dalilah Dahlan¹

Affiliations

¹ Department of Architecture, Faculty of Design and Architecture, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
² Department of Community Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
³ Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
⁴ Department of Psychiatry, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.

Abstract

Workplace architectural lighting conditions that are biologically dim during the day are causing healthy individuals to experience light-induced health and performance-related problems. Dynamic lighting was reported beneficial in supporting individuals' psychological behavior and physiological responses during work period in Europe. It has yet to be investigated in workplaces with minimal/no natural daylight contribution in tropical Malaysia. Hence, an exploratory experimental study was initiated in an experimental windowless open-plan workplace in Universiti Putra Malaysia, Serdang. The aim was to identify dynamic lighting configurations that were more supportive of a morning boosting effect than the control constant lighting, to support dayshift individuals' psychophysiological wellbeing indicators during the peak morning work period. The immediate impact of a 2-hour morning exposure to overhead white LED (6500 K) with different horizontal illuminance levels and oscillations (lighting patterns) were investigated on physiological indicator limited to urinary 6-sulfatoxymelatonin, and psychological indicators for alertness, mood, visual comfort, cognitive and visual task performance. Not all of the investigated dynamic lighting configurations were supportive of a morning boost. Only configurations 500increased to750 and 500increased to1000 lx therapeutically supported most of the indicators. Both these configurations suppressed urinary 6-sulfatoxymelatonin, and improved alertness, cognitive performance, positive affect, and visual comfort better than 'visit 1: 500constant500' lx (control). The increasing oscillation was observed more beneficial for the morning boost in tropical Malaysia, which is in reverse to that specified in the human rhythmic dynamic lighting protocol developed by researchers from the Netherlands for application during winter. The findings from this study present the feasibility of dynamic architectural lighting acting as an environmental therapeutic solution in supporting the individuals' psychophysiological wellbeing indicators in windowless open-plan workplace in tropical Malaysia. Further investigations on the two prospective configurations are recommended to determine the better supportive one for the morning boosting effect in Malaysia.

Publication types

Clinical Trial
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Affect / physiology*
Circadian Rhythm
Cognition / physiology*
Female
Humans
Lighting*
Malaysia
Male
Melatonin / analogs & derivatives
Melatonin / urine
Task Performance and Analysis*
Workplace*

Substances

6-sulfatoxymelatonin
Melatonin

Grants and funding

This study was funded by Universiti Putra Malaysia, grant name: Putra Grant—Putra Graduate Initiative (GP-IPS), grant number: GP-IPS/2016/9483800V, URL: http://www.rmc.upm.edu.my/perkhidmatan_kami/permohonan_geran_penyelidikan/geran_universiti_putra_malaysia_geran_putra-2720?L=en. RI received this funding. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.