Elevated internal exposure of children in simulated acute inhalation of volatile organic compounds: effects of concentration and duration
Elevated internal exposure of children in simulated acute inhalation of volatile organic compounds: effects of concentration and duration
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DOI：
10.1007/s00204-004-0599-3
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发表时间：
2005-02-01
影响因子：
6.1
通讯作者：
Gundert-Remy, U
中科院分区：
文献类型：
--
作者：
Abraham, K;Mielke, H;Gundert-Remy, U
近年来，在推导基于健康的接触限值时，人们越来越关注易受影响的亚群，特别是儿童。我们研究了儿童和成人吸入苯乙烯作为典型的3类挥发性有机化合物（VOC）时的动力学差异，即，一种具有低反应性和低水溶性的气体，允许高速率的肺泡吸收。根据急性接触指导水平（AEGL）方案中的情景，使用基于生理学的动力学模型，在广泛的空气传播浓度范围内（1-1000 ppm）模拟内部接触，接触时间长达8小时。从文献中获得特定解剖和生理参数以及特定化合物数据。儿童动脉血中的计算浓度高于成人，新生儿中最高。对于8小时暴露于低浓度，计算出的新生儿动脉浓度比成人高2.3倍。这主要是由于相对较高的通气率和不成熟的代谢。随着空气中浓度的增加，动脉浓度（新生儿/成人）的比率在环境空气中130 ppm时增加到最大值3.8，并随着浓度的进一步增加而下降到1.7。这是因为新生儿的代谢在比成人低的浓度下变得非线性。在高浓度下，代谢在两个年龄组中都达到饱和。对于较短的暴露，浓度比（新生儿/成人）的剂量依赖性不太明显。这是第一篇表明种内评估因子可能随暴露浓度和持续时间而变化的文章。
When deriving health-based exposure limits in recent years, increasing attention has been drawn to susceptible subpopulations, in particular to children. We investigated the differences in kinetics between children and adults during inhalation of styrene as a typical category-3 volatile organic compound (VOC), i.e., a gas with a low reactivity and low water solubility allowing a high rate of alveolar absorption. Internal exposure was simulated using a physiologically based kinetic model over a broad range of airborne concentrations (1-1000 ppm) and for an exposure time of up to 8 h according to the scenario in the acute exposure guideline level (AEGL) program. Age-specific anatomical and physiological parameters and compound-specific data was derived from the literature. The calculated concentrations in arterial blood are higher in children than in adults, and are highest in the newborn. For an 8-h exposure to low concentrations, the calculated arterial concentration in the newborn is higher by a factor of 2.3 than in the adult. This is due mainly to the relatively high ventilation rate and the immature metabolism. With increasing airborne concentration, the ratio of arterial concentrations (newborn/adult) increases to a maximum of 3.8 at 130 ppm in ambient air, and declines with further increments of concentration to a value of 1.7. This is because the metabolism of the newborn becomes non-linear at lower concentrations than in adults. At high concentrations, metabolism is saturated in both age groups. For shorter exposures, the dose dependency of the concentration ratios (newborn/adult) is less pronounced. This is the first article to show that the intraspecies assessment factor may vary with concentration and duration of exposure.