Spier C E, Little D E, Trim S C, Johnson T R, Linn W S, Hackney J D
Environmental Health Service, Rancho Los Amigos Medical Center, Downey, California.
J Expo Anal Environ Epidemiol. 1992 Jul-Sep;2(3):277-93.
We investigated activity patterns of 17 elementary school students aged 10-12, and 19 high school students aged 13-17, in suburban Los Angeles during the oxidant pollution season. Individuals' relationships between ventilation rate (VR) and heart rate (HR) were "calibrated" in supervised outdoor walking/jogging. Log VR was consistently proportional to HR; although "calibrations" were limited by a restricted range of exercise, and possibly by artifact due to mouthpiece breathing, which may cause overestimation of VR at rest. Each subject then recorded activities in diaries, and recorded HR once per minute by wearing Heart Watches, over 3 days (Saturday-Monday). For each activity the subject estimated a breathing rate--slow (like slow walking), medium (like fast walking), or fast (like running). VR ranges for each breathing rate and activity type were estimated from HR recordings. High-school students' diaries showed their aggregate distribution of waking hours as 68% slow inside, 8% slow outside, 10% medium inside, 9% medium outside, 1.5% fast inside, 1.5% fast outside. Elementary students' distribution was 47% slow inside, 15% slow outside, 20% medium inside, 12% medium outside, 2.5% fast inside, 3.5% fast outside. Sleep occupied 38% of high-school students' and 40% of elementary students' time; HR were generally lower in sleep than in slow waking activity. High school students' mean VR estimates were 13 L/min for slow breathing, 18 for medium, and 23 for fast; elementary students' were 14 slow, 18 medium, and 19 fast. VR distributions were approximately lognormal. Maximum estimated VR were approximately 70 L/min in elementary and approximately 100 L/min in high school students. Compared to adults studied similarly, students reported more medium or fast breathing, and had equal or higher VR estimates during slow and medium breathing despite their smaller size. These results suggest that, relative to body size, young people inhale larger doses of outdoor air pollutants than adults.
我们调查了17名年龄在10至12岁的小学生和19名年龄在13至17岁的高中生在洛杉矶郊区氧化剂污染季节的活动模式。在有监督的户外步行/慢跑过程中，对个体的通气率（VR）和心率（HR）之间的关系进行了“校准”。对数VR始终与HR成正比；尽管“校准”受到运动范围受限的限制，并且可能受到口含式呼吸导致的假象影响，口含式呼吸可能会导致静息时VR的高估。然后，每位受试者在日记中记录活动，并通过佩戴心率手表，在3天（周六至周一）内每分钟记录一次心率。对于每项活动，受试者估计呼吸频率——慢（如慢走）、中（如快走）或快（如跑步）。根据心率记录估算每种呼吸频率和活动类型的VR范围。高中生的日记显示，他们清醒时间的总体分布为：室内慢呼吸占68%，室外慢呼吸占8%，室内中呼吸占10%，室外中呼吸占9%，室内快呼吸占1.5%，室外快呼吸占1.5%。小学生的分布为：室内慢呼吸占47%，室外慢呼吸占15%，室内中呼吸占20%，室外中呼吸占12%，室内快呼吸占2.5%，室外快呼吸占3.5%。睡眠占高中生时间的38%，占小学生时间的40%；睡眠时的心率通常低于慢醒活动时的心率。高中生慢呼吸时的平均VR估计值为13升/分钟，中呼吸时为18升/分钟，快呼吸时为23升/分钟；小学生慢呼吸时为14升/分钟，中呼吸时为18升/分钟，快呼吸时为19升/分钟。VR分布近似对数正态分布。小学生的最大估计VR约为70升/分钟，高中生约为100升/分钟。与类似研究的成年人相比，学生报告的中呼吸或快呼吸更多，并且在慢呼吸和中呼吸期间，尽管他们体型较小，但VR估计值相等或更高。这些结果表明，相对于体型而言，年轻人吸入的室外空气污染物剂量比成年人更大。
