Table 4.
Particulate air pollution levels on heavy–AD and non–heavy AD days, by definition type
| Type of day (number of days) | SPM (μg/m3) |
PM2.5 (μg/m3) |
||
|---|---|---|---|---|
| Heavy–AD days, as per the definition by the JMA (n = 5) | 39.6 | ± 15.1 | 37.5 | ± 12.1 |
| Non–heavy AD days, as per the definition by the JMA (n = 87) | 17.9 | ± 8.9 | 17.6 | ± 7.3 |
| Heavy–AD days, defined by daily median level ≥ 0.07 km−1 (detected by LIDAR) (n = 5) | 35.0 | ± 16.7 | 31.3 | ± 15.6 |
| Non–heavy AD days, defined by daily median level ≥ 0.07 km−1 (detected by LIDAR) (n = 87) | 18.1 | ± 9.3 | 18.0 | ± 7.9 |
| Heavy–AD days, defined by hourly level ≥ 0.1 km−1 (detected by LIDAR) (n = 8) | 31.8 | ± 17.0 | 29.5 | ± 14.5 |
| Non–heavy AD days, defined by hourly level ≥ 0.1 km−1 (detected by LIDAR) (n = 84) | 17.8 | ± 8.8 | 17.7 | ± 7.5 |
| Heavy–AD days defined by hourly level ≥ 0.07 km−1 (detected by LIDAR) (n = 20) | 28.1 | ± 12.6 | 27.1 | ± 10.8 |
| Non–heavy AD days, defined by hourly level ≥ 0.07 km−1 (detected by LIDAR) (n = 72) | 16.6 | ± 8.2 | 16.6 | ± 6.9 |
AD Asian dust, JMA Japan Meteorological Agency, LIDAR light detection and ranging, PM 2.5 particulate matter smaller than 2.5 μm, SPM suspended particulate matter