Table 1.
Distribution of greenness and PM2.5 concentration by greenness group in North Carolina and Michigan, 2001–2016.
| Mean | SD | Min | 25% | 50% | 75% | Max | IQRw | ||
|---|---|---|---|---|---|---|---|---|---|
| NC | |||||||||
| NDVI | Total | 0.62 | 0.07 | 0.00 | 0.60 | 0.63 | 0.66 | 0.74 | 0.06 |
| Low | 0.55 | 0.08 | 0.00 | 0.54 | 0.58 | 0.60 | 0.61 | 0.05 | |
| Medium | 0.63 | 0.01 | 0.61 | 0.62 | 0.63 | 0.64 | 0.65 | 0.02 | |
| High | 0.67 | 0.02 | 0.65 | 0.66 | 0.67 | 0.69 | 0.74 | 0.03 | |
| PM2.5 | Total | 8.30 | 1.45 | 3.61 | 7.63 | 8.35 | 8.89 | 15.73 | 1.25 |
| Low | 8.78 | 1.37 | 4.16 | 8.00 | 8.54 | 9.09 | 15.73 | 1.09 | |
| Medium | 8.49 | 1.24 | 4.02 | 8.00 | 8.44 | 8.85 | 15.12 | 0.85 | |
| High | 7.63 | 1.47 | 3.61 | 6.64 | 7.76 | 8.55 | 15.10 | 1.91 | |
| MI | |||||||||
| NDVI | Total | 0.46 | 0.06 | 0.00 | 0.42 | 0.48 | 0.50 | 0.62 | 0.08 |
| Low | 0.39 | 0.04 | 0.00 | 0.37 | 0.40 | 0.42 | 0.45 | 0.05 | |
| Medium | 0.47 | 0.01 | 0.45 | 0.46 | 0.48 | 0.49 | 0.49 | 0.03 | |
| High | 0.52 | 0.02 | 0.49 | 0.50 | 0.51 | 0.53 | 0.62 | 0.02 | |
| PM2.5 | Total | 8.23 | 1.57 | 1.80 | 7.53 | 8.05 | 9.01 | 17.33 | 1.47 |
| Low | 8.75 | 1.61 | 1.80 | 7.63 | 8.32 | 9.53 | 17.33 | 1.90 | |
| Medium | 8.39 | 1.31 | 2.98 | 7.69 | 8.11 | 9.15 | 16.15 | 1.45 | |
| High | 7.55 | 1.50 | 2.77 | 6.97 | 7.84 | 8.14 | 15.57 | 1.18 | |
Greenness was divided in groups of low, medium, and high as tertiles; state-specific cutoffs for greenness group: low (<0.61), medium (0.61–0.65), and high (≥0.65) for NC; low (<0.45), medium (0.45–0.49), and high (≥0.49) for MI
SD indicates standard deviation; Min, minimum; Max, maximum; IQRw interquartile range width; NDVI, Normalized Difference Vegetation Index