Background and context
The importance of good mental health in the workplace has been demonstrated regularly recent in literature. As many as 14.7% of people report to experience mental health related issues in the workplace, which the Health and Safety Executive (HSE) equated led to ~17 million lost working days in 2021/2022. [1] [2] Alongside these statistics, the importance of good health and well-being in the workplace is further supported by the United Nations’ Sustainable Development Goals; given that adults spend the majority of their time in the workplace, ensuring a safe working environment is one of the critical factors in the maintenance of both mental and physical health. [7]

“Mental health needs to be seen as every bit as important as physical health within the workplace.”– World Health Organization

It is widely accepted that good occupational hygiene is a vital part of ensuring workplace health and safety by proactively acting to limit the risk factors. More recently, the focus has been directed towards mental health and the significant role it places in workplace well-being, productivity and job satisfaction, highlighting the importance of mental health within occupational hygiene. [8] Although well-being historically fell within its own sector, there has always been overlap with occupational hygiene (Figure. 1), and now occupational hygiene could pay an even greater role in supporting positive mental health due to the impact that working environments and conditions can have on individuals’ day-to-day well-being. [1] In this review, we explore some of the specific ways in which good occupational hygiene can support positive mental health in the workplace.

Discussion

The promotion of excellent occupational hygiene in the workplace, through training and awareness, is an essential way to support the health of the working population, both mentally and physically. A focus on good occupational hygiene by the employer, would proactively manage risks to health and safety before serious outcomes arise, such as depression or anxiety. [9] One of the main risk factors to poor mental health in the workplace is the changeable nature of working environments, with construction workers among those at the highest risk of suicide, noted at 3.7 times higher than the national average in 2020, and mental health concerns. [3] [10]

Good occupational hygiene in the workplace could directly improve mental health within these settings. When exploring some of the reasons behind poor mental health among construction workers, 21% of those questioned reported that a main concern is risk of injury or poor health and safety measures (Figure 2). [11] This result highlights the ongoing need for occupational hygiene training and how awareness of occupational hygiene can benefit workers within the construction industry particularly.

The Thames Tideway Tunnel project is a prime example of how good occupational hygiene can be easily incorporated into construction projects; with a dedicated team of occupational hygienists to improve awareness of health and safety as well as construction-related-ill-health which included stress-related issues and concerns. The Tideway team put in place multiple initiatives led by their team of occupational hygienists, such as actor-based trainings to drive engagement and the novel health impact frequency rate (HIFR), which had originally been designed and piloted during the construction of the Olympic Park for the London 2012 games, to regularly assess the quality of occupational hygiene and worker health. Ultimately, the occupational hygiene initiatives put in place led to exemplary scores in the Occupational Health Impact (OHI) Index, which takes into consideration areas such as stress. This demonstrated directly how good occupational hygiene can support positive mental health and well-being within a work-place setting. [4]

Figure 2: The causes of stress and anxiety among construction workers. Adapted from Bevan et al., 2022

Another factor which could be impacting the mental health of workers, and where good occupational hygiene can support positive mental health, has not been explored in as much detailed. However, there is emerging evidence that suggests air quality could directly impact employee well-being. [12] Air pollution is widely accepted as a physical risk factor to human health, with research now looking into the risk that air pollution poses to mental health generally, as well as with specific mental disorders. Poor air quality, defined in WHO guidelines as particulate matter with aerodynamic diameters of ≤2.5 μm (PM2.5) and ≤10 μm (PM10), including but not limited to ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide, can be improved directly through good occupational hygiene looking at air ventilation and appropriate personal protective equipment. [13]

Figure 3: Routes of adverse brain effects caused by particulate matter. Adapted from Bhui et al., 2023

An interesting area of research is the impact of small particulates that may be able to cross the blood-brain barrier once inhaled (Figure 3), these smaller particulates are also much more likely to be inhaled deeper into the lungs and have a greater impact on health. [13] Although it should be noted that further research is needed into this topic to address the current knowledge gaps, good occupational hygiene would ensure that all necessary ventilation measures are in place in line with any government guidelines, e.g., HSE for the UK. The involvement of an occupational hygienist, or the educating of workers on principles of air quality as part of an occupational hygiene qualification would allow for easy identification of any risk factors and ensure that air pollution is minimised to avoid any impact of poor air quality thus supporting the positive mental health of workers. [14]

Further to this, improvements to working conditions through good practice of occupational hygiene have proved especially beneficial to workers in high-strain jobs (high job demand, low job control) and potentially most beneficial to older employees due to age-specific effects of physical environments and job intensity. Estimates from a recent study suggested that good occupational hygiene, leading to improvements in the physical working environment, could drop the GHQ score for older workers by up to 4.37 points, and the risk of depression in these workers could also be reduced by 11.4 probability points. [5] These results quantify the impact of good occupational hygiene on supporting positive mental health within the workforce.

Conclusion

When considering the role that occupational hygiene plays in supporting good mental health, we must also consider tactics required to do so, improving awareness of occupational hygiene and medicine in the workplace through encouraging open discussion, prioritising safe working environments, and introducing well-being initiatives are all areas that can be explored further by employers when considering their approach to occupational hygiene. [6]
It is clear that good occupational hygiene supports positive mental health in the workplace by improving working conditions and proactively managing health risks. This is essential, as mental health significantly impacts productivity and well-being, with 14.7% of workers experiencing mental health issues. [1] Enhancing occupational health services (OHS) and awareness can mitigate work-related stress, depression, and anxiety, which in 2021/22 caused 17 million lost working days in the UK. [2] Effective occupational hygiene practices, such as ensuring air quality and safety measures, are particularly beneficial in high-risk industries like construction and other high-job demand, low-job control settings where we saw the biggest increases in mental health scoring following an improvement to the physical workplace environment in older employees. [13] [5] Additionally, promoting healthy environments and open dialogue can help bridge the gap between mental and physical health care, fostering overall employee well-being.

References
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[3] Demou, et al., “Group-level workplace interventions to improve mental health in low control, high-demand office-based jobs. A scoping review,” Annals of Work Exposures and Health, p. 68(4):335–350, 2024.
[4] Jones, et al., “Raising the bar for occupational health management in construction,” Proceedings of the Institution of Civil Engineers – Civil Engineering, p. 172(4):183-190, 2019.
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[6] The Lancet, “Improving mental health in the workplace,” The Lancet, p. 390(10107):P2015, 2017.
[7] British Occupational Hygiene Society (BOHS), “How Occupational Hygiene and Health Underpins Every One of The United Nations Sustainable Development Goals,” 2022.
[8] Consulting, Qualitas Occupational, “Emerging Trends in Occupational Hygiene: What Businesses Need to Know for 2024,” 2024. [Online]. Available: https://qualitasoc.com/trends-in-occupational-hygiene-2024/.
[9] Jain, et al., “The Role of Occupational Health Services in Psychosocial Risk Management and the Promotion of Mental Health and Well-Being at Work,” Int J Environ Res Public Health, p. 18(7):3632, 2021.
[10] Mates in Mind, “Mental Health in UK Construction: The Statistics,” 2022. [Online]. Available: https://www.matesinmind.org/news/mental-health-in-uk-construction-the-statistics.
[11] Bevan, et al., “Supporting the mental health of self employed construction workers” Institute for Employment Studies (IES), 2022.
[12] Christoforou, et al., “Elucidating an Association Between Air Pollution and Mental Health,” Annals of Work Exposures and Health, p. 67(Suppl 1):i90, 2023.
[13] Bhui, et al., “Air Quality and Mental Health: Evidence, Challenges and Future Directions,” BJPsych Open, p. 9(4):e120, 2023.
[14] Health and Safety Executive (HSE), “Ventilation in the Workplace,” [Online]. Available: https://www.hse.gov.uk/ventilation/overview.htm.