Table 1_Quantifying aerosol and microbial exposure of healthcare workers in endoscopy suites: a time-based study.docx

ObjectivesThis study aimed to quantify aerosol and microbial exposure levels during different working hours, analyze temporal air pollution trends in the endoscopy suite, and provide evidence to optimize infection prevention strategies.
MethodsA portable laser particle counter and an airborne bacteria sampler were used to measure aerosol particle concentrations and microbial loads at four time points: before the commencement of work (baseline), and 1, 2, and 3 h after work initiation. Continuous data collection was conducted over 10 consecutive working days. Air quality assessments were performed through scientific evaluation according to relevant international and national standards.
ResultsQualified rates for aerosols ≥0.5 μm increased by 20–30% during the 3 working hours compared to baseline levels. Microbial qualified rates remained at 100% throughout the study period. Aerosol concentrations across all particle sizes significantly increased with working hours (p < 0.01). The growth rate of 5–10 μm aerosols was higher than that of 0.3–5 μm particles (p < 0.01). After 3 h, concentrations of 0.5–25 μm and 0.3–10 μm aerosols increased by 1.48-fold and 1.3-fold compared to baseline values. Total microbial colonies positively correlated with work duration, polyp detection frequency, biopsy procedures performed, and procedure duration (p < 0.05). Microbial analysis identified 12 species, predominantly bacteria (79.6%) and fungi (20.4%).
ConclusionThis study highlights trends in aerosol and microbial contamination over time and identifies four factors influencing microbial counts in the endoscopy suite. We propose some recommendations to reduce exposure risks for HCWs and patients.

研究目的
本研究旨在量化不同工作时段的气溶胶（aerosol）与微生物暴露水平，分析内镜诊疗室（endoscopy suite）的空气污染时间变化趋势，并为优化感染防控策略提供依据。

研究方法
本研究采用便携式激光粒子计数器（portable laser particle counter）与空气微生物采样器（airborne bacteria sampler），在4个时间点分别测定气溶胶粒子浓度（aerosol particle concentrations）与微生物载荷（microbial loads）：工作开始前（基线（baseline）水平）、工作启动后1、2及3小时。连续10个工作日开展持续数据采集，并依据相关国际及国家标准开展科学的空气质量评估（air quality assessments）。

研究结果
与基线（baseline）水平相比，工作3小时内≥0.5μm气溶胶（aerosol）的合格率提升了20%~30%。研究全程微生物合格率均维持在100%。不同粒径（particle sizes）气溶胶浓度均随工作时长显著升高（p<0.01）；5~10μm粒径气溶胶的增长率（growth rate）高于0.3~5μm粒径粒子（p<0.01）。工作3小时后，0.5~25μm与0.3~10μm粒径气溶胶浓度较基线（baseline）分别升高1.48倍与1.3倍。总微生物菌落数（total microbial colonies）与工作时长、息肉检出频次（polyp detection frequency）、活检操作（biopsy procedures）次数及操作时长（procedure duration）均呈正相关（positively correlated）（p<0.05）。微生物分析共鉴定出12个物种，其中以细菌（79.6%）与真菌（20.4%）为主。

研究结论
本研究阐明了内镜诊疗室（endoscopy suite）气溶胶与微生物污染随时间的变化趋势，并明确了4项影响内镜室微生物计数的因素。本研究提出若干建议，以降低医护人员（Healthcare Workers，HCWs）与患者的暴露风险。