Table 1.
Baseline demographics and exposure of air pollutants in Taiwan.
| N = 161,970 | n | % | |
|---|---|---|---|
| Gender | Men | 70,948 | 43.8 |
| Women | 91,022 | 56.2 | |
| Age, years | mean, SD | 40.5 | 14.6 |
| Urbanization level | 1 (highest) | 55,898 | 34.5 |
| 2 | 52,644 | 32.5 | |
| 3 | 27,407 | 16.9 | |
| 4 (lowest) | 26,020 | 16.1 | |
| Exposure of air pollutants | |||
| SO2 level (daily average, ppb) | mean, SD | 4.98 | 2.41 |
| Min | 0.44 | ||
| Lower quartile | 3.38 | ||
| Median | 4.32 | ||
| Upper quartile | 6.03 | ||
| 90th percentile | 8.68 | ||
| Maximum | 14.1 | ||
| NOx level (daily average, ppb) | mean, SD | 36.3 | 35.1 |
| Min | 1.65 | ||
| Lower quartile | 23.4 | ||
| Median | 32.0 | ||
| Upper quartile | 38.6 | ||
| 90th percentile | 54.8 | ||
| Maximum | 426.7 | ||
| NO level (daily average, ppb) | mean, SD | 11.0 | 10.2 |
| Min | 0.32 | ||
| Lower quartile | 5.16 | ||
| Median | 8.58 | ||
| Upper quartile | 11.5 | ||
| 90th percentile | 24.1 | ||
| Maximum | 60.4 | ||
| NO2 level (daily average, ppb) | mean, SD | 22.6 | 6.57 |
| Min | 0.85 | ||
| Lower quartile | 18.2 | ||
| Median | 23.7 | ||
| Upper quartile | 24.5 | ||
| 90th percentile | 30.6 | ||
| Maximum | 38.6 | ||
| PM2.5 level (daily average, μg/m3) | mean, SD | 34.8 | 8.76 |
| Min | 1.00 | ||
| Lower quartile | 29.5 | ||
| Median | 33.3 | ||
| Upper quartile | 41.2 | ||
| 90th percentile | 47.7 | ||
| Maximum | 113.2 | ||
| Outcome | |||
| Nephrotic syndrome | Yes | 776 | 0.48 |
| Follow-up time, years | mean, SD | 11.7 | 0.99 |
The urbanization level was categorized by the population density of the residential area into 4 levels, with level 1 as the most urbanized and level 4 as the least urbanized. SO2, sulfur dioxide; NOx, nitrogen oxides; NO, nitrogen monoxide; NO2, nitrogen dioxide; PM, particulate matter; PM2.5, particles with aerodynamic diameter < 2.5 μm; SD, standard deviation.