Table 3. Seasonal variation in PM2.5 and its chemical components in Nagoya from April 2003 to December 2007.
| Spring | Summer | Autumn | Winter | |||||||||
| n | Mean (µg/m3) |
(SD) (µg/m3) |
n | Mean (µg/m3) |
(SD) (µg/m3) |
n | Mean (µg/m3) |
(SD) (µg/m3) |
n | Mean (µg/m3) |
(SD) (µg/m3) |
|
| PM2.5 | 165 | 24.56 | (11.20) | 321 | 22.56 | (11.23) | 166 | 24.86 | (14.52) | 274 | 23.79 | (13.97) |
| Sulfate | 165 | 6.39 | (3.82) | 321 | 6.75 | (5.04) | 166 | 4.47 | (3.32) | 274 | 4.35 | (3.13) |
| Nitrate | 165 | 1.83 | (2.25) | 321 | 0.56 | (1.18) | 166 | 1.37 | (1.67) | 274 | 2.33 | (2.48) |
| Chloride | 165 | 0.16 | (0.25) | 321 | 0.04 | (0.09) | 166 | 0.29 | (0.39) | 274 | 0.62 | (0.59) |
| Ammonium | 162 | 2.96 | (1.72) | 321 | 2.65 | (1.89) | 166 | 2.15 | (1.75) | 274 | 2.62 | (1.92) |
| Sodium | 162 | 0.16 | (0.09) | 321 | 0.14 | (0.10) | 166 | 0.17 | (0.09) | 274 | 0.14 | (0.08) |
| Potassium | 162 | 0.16 | (0.10) | 321 | 0.12 | (0.09) | 166 | 0.17 | (0.11) | 274 | 0.16 | (0.11) |
| Magnesium | 162 | 0.02 | (0.01) | 321 | 0.02 | (0.01) | 166 | 0.02 | (0.01) | 274 | 0.02 | (0.01) |
| Calcium | 162 | 0.07 | (0.08) | 321 | 0.04 | (0.04) | 166 | 0.05 | (0.05) | 274 | 0.05 | (0.05) |
| Elemental carbon | 148 | 3.04 | (1.84) | 309 | 3.43 | (1.68) | 155 | 4.20 | (2.62) | 274 | 3.60 | (2.35) |
| Organic carbon | 148 | 4.61 | (2.22) | 309 | 4.44 | (1.74) | 155 | 5.52 | (2.50) | 274 | 4.86 | (2.24) |
PM2.5, fine particulate matter; SD, standard deviation.