Henry R J, Borganelli G N
Department of Pediatric Dentistry, University of Texas, USA.
Int J Paediatr Dent. 1995 Sep;5(3):157-61. doi: 10.1111/j.1365-263x.1995.tb00299.x.
Occupational exposure to low levels of nitrous oxide (N2O) have been associated with adverse health effects. The National Institute for Occupational Safety and Health has established a threshold guideline of 25 ppm N2O. The purpose of this laboratory study was to determine the effectiveness of a high-volume dental aspirator as a supplemental device to reduce ambient N2O levels in the operatory. The investigation evaluated four experimental groups that were assigned based on whether or not the aspirator was used and on the rate at which operatory ventilation was established (5 or 10 room air exchanges per hour). Ambient N2O levels were monitored at 30 cm from the nasal hood using an infrared spectrophotometer. The room air exchange rate was measured with a flow hood and then manipulated to the desired ventilation rate. N2O levels were detected with a spectrophotometer and data were recorded with a microprocessor that continuously collected data. The results demonstrated that both utilization of supplemental oral aspiration and increased operatory ventilation significantly reduced ambient N2O levels. It was concluded that a high-volume aspirator, when used in conjunction with the normal scavenging system, can significantly reduce ambient N2O levels to within the guidelines established by the National Institute for Occupational Safety and Health.
职业接触低水平的一氧化二氮（N₂O）已被证实与不良健康影响有关。美国国家职业安全与健康研究所已制定了25 ppm N₂O的阈值指南。本实验室研究的目的是确定大容量牙科抽吸器作为一种辅助设备，在操作间降低周围环境中N₂O水平的有效性。该调查评估了四个实验组，这些实验组是根据是否使用抽吸器以及操作间通风建立的速率（每小时5次或10次室内空气交换）来分配的。使用红外分光光度计在距鼻罩30厘米处监测周围环境中的N₂O水平。使用通风罩测量室内空气交换率，然后将其调节到所需的通风速率。用分光光度计检测N₂O水平，并用微处理器记录数据，该微处理器可连续收集数据。结果表明，使用辅助口腔抽吸和增加操作间通风均可显著降低周围环境中的N₂O水平。研究得出的结论是，大容量抽吸器与正常的清除系统一起使用时，可将周围环境中的N₂O水平显著降低至美国国家职业安全与健康研究所制定的指南范围内。
