Health Effects of Underground Workspaces (HEUW) cohort in Singapore: study design and baseline characteristics

The development of underground workspaces is a strategic effort towards healthy urban growth in ever-increasing land-scarce cities. Despite the growth in underground workspaces, there is limited information regarding the impact of this environment on worker’s health. The Health Effects of Underground Workspaces (HEUW) study is a cohort study which was set up to examine the health effects of working in underground workspaces. In this paper, we describe the rationale for the study, study design, data collection and baseline characteristics of participants. The HEUW study recruited 464 participants at baseline, of which 424 (91.4%) were followed-up at three months, and 334 (72.0%) after 12 months from baseline. We used standardized and validated questionnaires to collect information on socio-demographic and lifestyle characteristics, medical history, family history of chronic diseases, sleep quality, health-related quality of life, chronotype, psychological distress, occupational factors, and comfort levels with indoor environmental quality parameters. Clinical and anthropometric parameters including blood pressure, spirometry, height, weight, waist and hip circumference were also measured. Biochemical tests of participant’s blood and urine samples were conducted to measure glucose, lipids and melatonin levels. We also conducted objective measurements of an individual’s workplace environment, assessing air quality, light intensity, temperature, thermal comfort, bacterial and fungal counts. Findings from this study will help to identify modifiable lifestyle and environmental parameters that are negatively affecting worker’s health. The findings may be used to guide the development of more health-promoting workspaces that attempt to negate any potential negative health effects from working in underground workspaces