A method for measuring upper respiratory tract vapor uptake and its applicability to quantitative inhalation risk assessment.
A method for measuring upper respiratory tract vapor uptake and its applicability to quantitative inhalation risk assessment.
复制标题
一种测量上呼吸道蒸气吸收的方法及其在定量吸入风险评估中的适用性。
DOI：
10.1080/089583799196727
复制
发表时间：
1999
影响因子：
2.1
通讯作者：
Morris,JB
中科院分区：
文献类型：
--
作者：
Morris,JB
要彻底了解任何物质的毒性，就需要了解接触浓度与传递到关键目标部位的剂量之间的关系。对于吸入暴露尤其如此，因为吸入的颗粒和蒸汽不会均匀地存款在呼吸道中。本报告详细描述了测量大鼠上呼吸道（URT）吸收蒸汽的方法。使用麻醉的动物模型，其中插入两个气管内导管：一个通向肺以促进呼吸，另一个通向鼻子以允许通过鼻道进行空气采样。将动物置于仅鼻暴露室中，通过鼻吸入试验蒸汽长达1 h。根据吸入（灭菌室）空气和排出URT的空气之间的蒸汽浓度差计算吸收效率。摄取数据提供乙醛和尼古丁蒸汽，并建议实验设计，包括多个空气流动制度和吸入浓度进行说明。由于非生理气流状态和手术的侵入性，通过这种方法获得的数据不一定反映正常呼吸动物的吸收效率。这样得到的数据最好用于支持和验证国家的最先进的区域蒸汽吸收的数学模拟模型。这些模型提高了科学的严谨性，减少了吸入材料定量风险评估的不确定性。
A thorough understanding of the toxicity of any substance requires knowledge of the relationships between exposure concentration and dose delivered to the critical target site. This is particularly true for inhalation exposures because inspired particles and vapors do not deposit uniformly in the respiratory tract. The current report describes in detail a methodology for measuring upper respiratory tract (URT) uptake of vapors in the rat. A urethane-anesthetized animal model is utilized in which two endotracheal tubes are inserted: one leading toward the lung to facilitate respiration, and the other toward the nose to allow air sampling through the nasal passages. The animal is placed in a nose-only exposure chamber and test vapor is drawn through the nose for periods up to 1 h. Uptake efficiency is calculated from the difference in vapor concentration between the inspired (chamber) air and air exiting the URT. Uptake data are provided for acetaldehyde and nicotine vapors, and a suggested experimental design that includes multiple air flow regimes and inspired concentrations is described. The data obtained by this methodology are not necessarily reflective of uptake efficiencies in normally breathing animals due to the nonphysiologic airflow regimes and the invasiveness of the procedure. The data so obtained are best utilized to support and validate state-ofthe-art mathematical simulation models of regional vapor uptake. These models increase scientific rigor and reduce uncertainty in quantitative risk assessments for inhaled materials.