Table 2.
Ratios between different air pollutants during different heavily polluted episodes in Beijing.
| Airborne pollutants | Stations | During other heavily polluted days | During the first alert | During the Second alert |
|---|---|---|---|---|
| PM2.5/SO2 | JCZX | 16.705 | 8.269 | 8.697 |
| DL | 15.043 | 11.314 | 11.385 | |
| YF | 8.033 | 15.243 | 27.141 | |
| PM2.5/CO | JCZX | 0.080 | 0.056 | 0.053 |
| DL | 0.082 | 0.063 | 0.070 | |
| YF | 0.066 | 0.054 | 0.052 | |
| PM2.5/NO2 | JCZX | 2.593 | 2.233 | 2.097 |
| DL | 3.565 | 2.790 | 3.035 | |
| YF | 3.622 | 3.662 | 3.708 | |
| SO2/CO | JCZX | 0.011 | 0.008 | 0.008 |
| DL | 0.011 | 0.008 | 0.012 | |
| YF | 0.008 | 0.004 | 0.002 | |
| NO2/CO | JCZX | 0.032 | 0.028 | 0.027 |
| DL | 0.026 | 0.023 | 0.025 | |
| YF | 0.018 | 0.015 | 0.014 | |
| PM2.5 accumulation rate/μg · m−3 · h−1 | JCZX | 5.6 | 1.8 | 3.9 |
| DL | 5.1 | 1.6 | 3.5 | |
| YF | 5.8 | 5.7 | 5.8 |
PM 2.5 accumulation rate = (Max PM2.5 concentration- 150 μg · m−3)/polluted hours.