Table 2: Correlation coefficient (r) between ozone concentrations in Japan and industrial waste gas emissions in China from 2000 to 2009.
| Pref. | Number of stations | ( r ) 1-hr | ( r ) max. 1-hr |
| Hokkaido | 23 | 0.80 | 0.78 |
| Aomori | 6 | 0.60 | 0.48 |
| Akita | 5 | 0.70 | 0.53 |
| Yamagata | 10 | -0.67 | -0.80 |
| Niigata | 28 | 0.98 | 0.96 |
| Toyama | 25 | 0.20 | -0.19 |
| Ishikawa | 22 | 0.80 | 0.58 |
| Fukui | 22 | 0.89 | 0.70 |
| Tottori | 3 | 0.76 | 0.51 |
| Shimane | 7 | -0.35 | -0.66 |
| Yamaguchi | 19 | 0.89 | 0.81 |
| Fukuoka | 40 | 0.84 | 0.81 |
| Saga | 9 | 0.82 | 0.82 |
| Nagasaki | 18 | 0.85 | 0.84 |
| Kumamoto | 20 | 0.91 | 0.91 |
| Kagoshima | 9 | 0.83 | 0.76 |
| Okinawa | 4 | 0.08 | -0.13 |