Takishima T, Nakamura M, Sasaki M, Miyano M, Yamaya M, Sasaki H
First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
Am Rev Respir Dis. 1987 Nov;136(5):1278-80. doi: 10.1164/ajrccm/136.5.1278.
We measured pneumomagnetic field strength (PMFS) in 42 healthy control subjects living in districts of Northern Japan with low levels of road dust pollution and in 39 healthy subjects living in areas with high levels of road dust pollution. Suspended road dust produced by studded tires increases from 30 micrograms/m3 during the summer season to levels as high as 400 micrograms/m3 during the snow season in the downtown areas of Sendai, Japan. Road dust retained in the lungs, containing 3% iron, was magnetized from the surface of the chest wall, and PMFS was measured. Three to 5 sequential PMFS measurements were made in each subject in March and October of 1984 and 1985, and in March 1986. The PMFS in control subjects in March 1984 was 37 +/- 14 pico-Tesla (mean +/- SD) and did not significantly differ from the PMFS in October 1984 or that in March 1985. In March 1984, the PMFS of the subjects in highly polluted areas was 95 +/- 100 pico-Tesla (mean +/- SD) and was significantly higher than that of control subjects (p less than 0.01) and subsequently decreased in March 1985 and in March 1986, corresponding to a decrease in suspended road dust brought about by a campaign to eliminate the use of studded tires. Our findings suggest that some road dust caused by studded tires is retained in the lungs.
我们测量了居住在日本北部道路灰尘污染水平较低地区的42名健康对照者以及居住在道路灰尘污染水平较高地区的39名健康者的肺磁场强度（PMFS）。在日本仙台市中心，防滑轮胎产生的悬浮道路灰尘在夏季为30微克/立方米，在雪季可高达400微克/立方米。滞留在肺部的道路灰尘含铁量为3%，会从胸壁表面被磁化，进而测量PMFS。在1984年和1985年的3月和10月以及1986年3月，对每位受试者进行了3至5次连续的PMFS测量。1984年3月对照者的PMFS为37±14皮特斯拉（平均值±标准差），与1984年10月或1985年3月的PMFS无显著差异。1984年3月，高污染地区受试者的PMFS为95±100皮特斯拉（平均值±标准差），显著高于对照者（p<0.01），随后在1985年3月和1986年3月下降，这与消除防滑轮胎使用运动导致的悬浮道路灰尘减少相对应。我们的研究结果表明，防滑轮胎产生的一些道路灰尘会滞留在肺部。
