Ambient air pollution in gastrointestinal endoscopy unit

Background The gastrointestinal endoscopy unit is frequently exposed to gastrointestinal gas expelled from patients and electrocoagulated tissue through carbonation. This can be potentially harmful to the health of not only the healthcare personnel but also patients who undergo endoscopy. This study aimed to measure the air quality in the endoscopy unit. Methods We measured indoor air quality indices (CO 2 , total volatile organic compounds (VOCs), PM 2.5 , NO 2 , CO, and ozone) using portable passive air quality monitoring sensors in the procedural area, recovery area, and cleansing-of-equipment area, at 1-min intervals for 1 week, and the type and number of endoscopic procedures were recorded. Results CO 2 , PM 2.5 , NO 2 , and ozone levels were the highest in the cleansing area, followed by the procedural and recovery areas, and VOC level was highest in the procedural area. The proportion of poor-quality level of CO 2 and VOCs was highest in the procedural area and that of NO 2 was highest in the cleansing area. The proportion of tolerable to poor-quality (exceeding acceptable level) level of CO 2 and total VOCs in the procedural area was 26% and 19.2% in all measurement times, respectively. The proportion of tolerable to poor-quality level of NO 2 in the cleansing area of the endoscopy unit was 32.1% in all measurement times. Multivariate analyses revealed that tolerable to poor-quality (exceeding acceptable level) level of VOCs was associated with the number of endoscopic procedures (odds ratio, 1.79; 95% confidence interval, 1.42–2.27) and PM 2.5 level (1.27, 1.12–1.44). Moreover, tolerable to poor-quality level of CO 2 was associated with the number of colonoscopy (5.35, 1.19–24.02), especially with electrocoagulation procedures (24.31, 1.31–452.44) in the procedural area. Conclusions Healthcare personnel and patients who undergo endoscopy are frequently exposed to ambient air pollution. Health-related protective strategies for ambient air pollution in the endoscopy unit are warranted. ClinicalTrials.gov registration number NCT03724565.