Study Reveals Impact of Lighting and Noise on ICU Staff Productivity

A recent study conducted in a Tokyo hospital’s intensive care unit (ICU) has highlighted how lighting and noise levels significantly affect healthcare workers’ satisfaction and productivity. Over a three-month period, researchers assessed the indoor environmental quality (IEQ) in the ICU, revealing that insufficient natural light and excessive ambient noise contribute to a challenging work environment for medical staff.

The findings, led by Assistant Professor Wataru Umishio and Associate Professor Takuya Oki from the Institute of Science Tokyo, suggest that improving these environmental factors can enhance not only worker satisfaction but also the quality of patient care. The study was conducted between July and September 2023 and published in the journal Intensive and Critical Care Nursing.

Impact of Environmental Factors on Healthcare Workers

ICUs are inherently noisy environments due to life-support machines and the rapid movement of healthcare professionals attending to patients. This noise, coupled with limited access to natural light, creates a stressful and fatiguing atmosphere. The Japanese Ministry of Health, Labor, and Welfare has recognized the importance of addressing these issues in its work-style reforms, which began in April 2024 to improve conditions for healthcare workers.

The Japanese Society of Intensive Care Medicine (JSICM) has established guidelines to enhance patient comfort, which indirectly supports healthcare workers by reducing their stress levels. These guidelines include recommendations for optimal lighting, noise reduction, and maintaining acceptable temperature and humidity levels.

Research conducted by the team at the Institute of Science Tokyo involved both objective measurements of air quality and subjective assessments through questionnaires distributed to ICU staff. The study examined four key IEQ domains: thermal comfort, lighting, acoustics, and air quality.

Findings and Recommendations for Future ICU Design

The results indicated that while air quality metrics were generally within acceptable limits for carbon dioxide and particulate matter, lighting and noise levels fell short of the JSICM recommendations. Specifically, light illuminance varied widely, with some areas receiving adequate natural daylight while others did not. Noise levels exceeded the recommended limits, and temperatures in single-bed rooms were approximately 3 °C below what is considered optimal.

Survey responses reflected these concerns, with over 60% of healthcare workers expressing dissatisfaction with the overall IEQ in the ICU. Dissatisfaction was particularly pronounced regarding the acoustic environment, where nearly three-quarters of respondents reported issues related to noise from medical equipment and inadequate natural light.

Umishio emphasized the need for future ICU designs to prioritize elements that support both staff productivity and patient care. He advocates for the implementation of designs that integrate daylight and robust acoustic solutions, stating, “Coordinated efforts between architectural environmental engineering and critical care teams offer a practical pathway to enhance staff experience.”

The study underscores the critical need for healthcare facilities to consider environmental factors that impact worker productivity and well-being. By addressing lighting and noise issues, hospitals can create more effective and supportive work environments for their staff, ultimately benefiting patient outcomes as well.

For more information, refer to the study by Wataru Umishio et al, titled “Multi-domain indoor environmental quality in intensive care units from a healthcare worker perspective: An observational study in Japan,” published in Intensive and Critical Care Nursing (2026). DOI: 10.1016/j.iccn.2025.104257.