Table 1. Average concentrations* of atmospheric air pollutants in the study communities.
| SPM (µg/m3) Mean (SD) |
NO2 (ppb) Mean (SD) |
SO2 (ppb) Mean (SD) |
|
| Ichikawa (School A) | 41.7 (3.2) | 25.3 (2.5) | 6.3 (0.6) |
| Ichikawa (School B) | 42.7 (2.9) | 23.7 (1.5) | 6.3 (0.6) |
| Ichikawa (School C) | 40.3 (6.5) | 29.0 (2.0) | 6.3 (1.5) |
| Kimitsu | 28.0 (1.0) | 19.0 (1.0) | 4.7 (1.2) |
| Obitsu | 26.7 (2.5) | 11.7 (2.1) | 4.3 (0.6) |
*: Data are shown as the mean values (SD) of the annual average concentrations of air pollutants for the 3 year period 1998-2000, measured at ambient air monitoring stations located near the study schools.
SPM: Suspended particulate matter
NO2: Nitrogen dioxide
SO2: Sulfur dioxide
ppb: parts per billion
SD: Standard deviation