Choi Young W, Sunderman Michelle M, McCauley Martha W, Richter William R, Willenberg Zachary J, Wood Joseph, Serre Shannon, Mickelsen Leroy, Willison Stuart, Rupert Rich, Muñiz-Ortiz Jorge G, Casey Sara, Calfee M Worth
Battelle Memorial Institute, Columbus, OH, USA.
US Environmental Protection Agency, TW Alexander Drive, Research Triangle Park, NC, USA.
Appl Biosaf. 2021 Sep;26(3):139-53. doi: 10.1089/apb.21.926975. Epub 2021 Apr 9.
This study investigated formaldehyde decontamination efficacy against dried spores on porous and non-porous test surfaces, under various environmental conditions. This knowledge will help responders determine effective formaldehyde exposure parameters to decontaminate affected spaces following a biological agent release.
Prescribed masses of paraformaldehyde or formalin were sublimated or evaporated, respectively, to generate formaldehyde vapor within a bench-scale test chamber. Adsorbent cartridges were used to measure formaldehyde vapor concentrations in the chamber at pre-determined times. A validated method was used to extract the cartridges and analyze for formaldehyde via liquid chromatography. Spores of , , and were inoculated and dried onto porous bare pine wood and non-porous painted concrete material coupons. A series of tests was conducted where temperature, relative humidity, and formaldehyde concentration were varied, to determine treatment efficacy outside of conditions where this decontaminant is well-characterized (laboratory temperature and humidity and 12 mg/L theoretical formaldehyde vapor concentration) to predict decontamination efficacy in applications that may arise following a biological incident.
Low temperature trials (approximately 10°C) resulted in decreased formaldehyde air concentrations throughout the 48-hour time-course when compared with formaldehyde concentrations collected in the ambient temperature trials (approximately 22°C). Generally, decontamination efficacy on wood was lower for all three spore types compared with painted concrete. Also, higher recoveries resulted from painted concrete compared to wood, consistent with historical data on these materials. The highest decontamination efficacies were observed on the spores subjected to the longest exposures (48 hours) on both materials, with efficacies that gradually decreased with shorter exposures. Adsorption or absorption of the formaldehyde vapor may have been a factor, especially during the low temperature trials, resulting in less available formaldehyde in the air when measured.
Environmental conditions affect formaldehyde concentrations in the air and thereby affect decontamination efficacy. Efficacy is also impacted by the material with which the contaminants are in contact.
本研究调查了在各种环境条件下，甲醛对多孔和无孔测试表面上干燥孢子的去污效果。这些知识将有助于应急人员确定有效的甲醛暴露参数，以便在生物制剂释放后对受影响空间进行去污处理。
分别升华规定质量的多聚甲醛或蒸发福尔马林，在台式试验箱内产生甲醛蒸气。使用吸附剂滤筒在预定时间测量试验箱内的甲醛蒸气浓度。采用经过验证的方法提取滤筒，并通过液相色谱法分析甲醛。将炭疽芽孢杆菌、肉毒杆菌和产气荚膜梭菌的孢子接种并干燥在多孔裸松木和无孔涂漆混凝土材料试片上。进行了一系列试验，改变温度、相对湿度和甲醛浓度，以确定在该去污剂特性明确的条件（实验室温度和湿度以及12mg/L理论甲醛蒸气浓度）之外的处理效果，从而预测生物事件后可能出现的应用中的去污效果。
与在环境温度试验（约22°C）中收集的甲醛浓度相比，低温试验（约10°C）在整个48小时的时间过程中导致甲醛空气浓度降低。一般来说，与涂漆混凝土相比，所有三种孢子类型在木材上的去污效果都较低。此外，与木材相比，涂漆混凝土的回收率更高，这与这些材料的历史数据一致。在两种材料上暴露时间最长（48小时）的孢子的去污效果最高，随着暴露时间缩短，去污效果逐渐降低。甲醛蒸气的吸附或吸收可能是一个因素，特别是在低温试验期间，导致测量时空气中可用的甲醛较少。
环境条件会影响空气中的甲醛浓度，从而影响去污效果。去污效果还受到污染物接触材料的影响。
