Wallace L, Nelson W, Ziegenfus R, Pellizzari E, Michael L, Whitmore R, Zelon H, Hartwell T, Perritt R, Westerdahl D
U.S. Environmental Protection Agency, Washington, DC.
J Expo Anal Environ Epidemiol. 1991 Apr;1(2):157-92.
The U.S. Environmental Protection Agency and the California Air Resources Board studied the exposures of 51 residents of Los Angeles, California, to 25 volatile organic chemicals (VOCs) in air and drinking water in 1987. A major goal of the study was to measure personal, indoor, and outdoor air concentrations, and breath concentrations of VOCs in persons living in households that had previously been measured in 1984. Other goals were to confirm the marked day-night and seasonal differences observed in 1984; to determine room-to-room variability within homes; to determine source emission rates by measuring air exchange rates in each home; and to extend the coverage of chemicals by employing additional sampling and analysis methods. A total of 51 homes were visited in February of 1987, and 43 of these were revisited in July of 1987. The results confirmed previous TEAM Study findings of higher personal and indoor air concentrations than outdoor concentrations of all prevalent chemicals (except carbon tetrachloride); higher personal, indoor, and outdoor air concentrations in winter than in summer; and (in winter only) higher outdoor concentrations at night than in the daytime. New findings included the following: (1) room-to-room variability of 12-hour average concentrations was very small, indicating that a single monitor may be adequate for estimating indoor concentrations over this time span; (2) "whole-house" source emission rates were relatively constant during both seasons, with higher rates for odorous chemicals such as p-dichlorobenzene and limonene (often used in room air fresheners) than for other classes of chemicals; (3) breath concentrations measured during morning and evening were similar for most participants, suggesting the suitability of breath measurements for estimating exposure in the home; (4) limited data obtained on two additional chemicals-toluene and methylene chloride-indicated that both were prevalent at fairly high concentrations and that indoor air concentrations exceeded outdoor concentrations by a factor of about three.
1987年，美国环境保护局和加利福尼亚空气资源委员会对加利福尼亚州洛杉矶市的51名居民接触空气和饮用水中25种挥发性有机化合物（VOCs）的情况进行了研究。该研究的一个主要目标是测量1984年曾进行过测量的家庭中居民的个人、室内和室外空气中VOCs的浓度以及呼出气体中的浓度。其他目标包括确认1984年观察到的显著的昼夜和季节差异；确定家庭内各个房间之间的差异；通过测量每个家庭的空气交换率来确定源排放率；以及采用额外的采样和分析方法扩大化学物质的覆盖范围。1987年2月共走访了51户家庭，其中43户在1987年7月再次接受走访。结果证实了之前“室内环境暴露测量（TEAM）研究”的发现：所有常见化学物质（四氯化碳除外）的个人和室内空气浓度高于室外浓度；冬季的个人、室内和室外空气浓度高于夏季；并且（仅在冬季）夜间的室外浓度高于白天。新的发现包括：（1）12小时平均浓度在各个房间之间的差异非常小，这表明在这个时间段内，使用单个监测器可能就足以估算室内浓度；（2）两个季节中“全屋”源排放率相对恒定，对于有气味的化学物质，如对二氯苯和柠檬烯（常用于室内空气清新剂），其排放率高于其他类别的化学物质；（3）大多数参与者在早晨和晚上测量的呼出气体浓度相似，这表明呼出气体测量适用于估算家庭中的暴露情况；（4）关于另外两种化学物质——甲苯和二氯甲烷——获得的有限数据表明，这两种物质都普遍存在且浓度相当高，并且室内空气浓度比室外浓度高出约三倍。
