Norkaew Saowanee, Narikawa Sumiyo, Nagashima Ukyo, Uemura Ryoko, Noda Jun
Faculty of Public Health, Thammasat University, Khlong Nueng, Klong Luang, Pathum Thani, 12121, Thailand.
Research Unit in Occupational Ergonomics, Thammasat University, Khlong Nueng, Klong Luang, Pathum Thani, 12121, Thailand.
Heliyon. 2024 Feb 22;10(5):e26574. doi: 10.1016/j.heliyon.2024.e26574. eCollection 2024 Mar 15.
The COVID-19 pandemic highlighted the dangers of airborne transmission and the risks of pathogen-containing small airborne droplet inhalation as an infection route. As a pathogen control, Weakly Acidic Hypochlorous Water (WAHW) is used for surface disinfection. However, there are limited assessments of air disinfection by WAHW against airborne pathogens like bioaerosols. This was an empirical study evaluating the disinfection efficacy of WAHW in an atmospheric simulation chamber system against four selected model bacteria. The strains tested included (SA), (EC), (PA), and (PAO1). Each bacterial solution was nebulized into the chamber system as the initial step, and bioaerosol was collected into the liquid medium by a bio-sampler for colony forming units (CFU) determination. Secondly, the nebulized bacterial bioaerosol was exposed to nebulized double distilled water (DDW) as the control and nebulized 150 ppm of WAHW as the experimental groups. After the 3 and 30-min reaction periods, the aerosol mixture inside the chamber was sampled in liquid media and then cultured on agar plates with different dilution factors to determine the CFU. Survival rates were calculated by a pre-exposed CFU value as a reference point. The use of WAHW decreased bacterial survival rates to 1.65-30.15% compared to the DDW control. PAO1 showed the highest survival rates and stability at 3 min was higher than 30 min in all experiments. Statistical analysis indicated that bacteria survival rates were significantly reduced compared to the controls. This work verifies the bactericidal effects against Gram-positive/negative bioaerosols of WAHW treatment. As WAHW contains chlorine in the acid solution, residual chlorine air concentration is a concern and the disinfection effect at different concentrations also requires investigation. Future studies should identify optimal times to minimize the treated time range and require measurements in a real environment.
新冠疫情凸显了空气传播的危险性以及吸入含病原体的微小空气飞沫作为一种感染途径的风险。作为一种病原体控制手段，弱酸性次氯酸水（WAHW）被用于表面消毒。然而，关于WAHW对生物气溶胶等空气传播病原体进行空气消毒的评估有限。这是一项实证研究，评估了WAHW在大气模拟舱系统中对四种选定的模式细菌的消毒效果。测试的菌株包括金黄色葡萄球菌（SA）、大肠杆菌（EC）、铜绿假单胞菌（PA）和恶臭假单胞菌（PAO1）。作为第一步，将每种细菌溶液雾化到舱系统中，然后通过生物采样器将生物气溶胶收集到液体培养基中以测定菌落形成单位（CFU）。其次，将雾化的细菌生物气溶胶暴露于雾化的双蒸水（DDW）作为对照组，以及雾化的150 ppm WAHW作为实验组。在3分钟和30分钟的反应期后，对舱内的气溶胶混合物在液体培养基中进行采样，然后在具有不同稀释因子的琼脂平板上培养以确定CFU。以预先暴露的CFU值作为参考点计算存活率。与DDW对照组相比，使用WAHW可将细菌存活率降低至1.65 - 30.15%。在所有实验中，PAO1显示出最高的存活率，且3分钟时的稳定性高于30分钟时。统计分析表明，与对照组相比，细菌存活率显著降低。这项工作验证了WAHW处理对革兰氏阳性/阴性生物气溶胶的杀菌效果。由于WAHW在酸性溶液中含有氯，残余氯的空气浓度是一个问题，不同浓度下的消毒效果也需要研究。未来的研究应确定最佳时间，以尽量缩短处理时间范围，并需要在实际环境中进行测量。
