Table 1.
Characteristics of 857 Children With Information on Greenness Exposures and Mid-Childhood Cognitive Outcomes, Project Viva, Massachusetts, 1999–2010
| NDVI Early Childhood | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Variable | Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | Overall | |||||
| % | Mean (SD) | % | Mean (SD) | % | Mean (SD) | % | Mean (SD) | % | Mean (SD) | |
| Female sex | 43.22 | 58.42 | 49.32 | 54.04 | 51.34 | |||||
| White race | 56.78 | 61.88 | 78.73 | 84.68 | 71.30 | |||||
| Mother’s education level | ||||||||||
| Some college | 29.15 | 23.76 | 19.46 | 11.06 | 20.42 | |||||
| College degree or more | 60.80 | 71.78 | 77.38 | 86.38 | 74.68 | |||||
| Father’s education level | ||||||||||
| Some college | 26.63 | 26.24 | 19.46 | 11.91 | 20.65 | |||||
| College degree or more | 54.77 | 61.39 | 73.30 | 82.55 | 68.73 | |||||
| Household income at enrollment, $ | ||||||||||
| 40,000–70,000 | 29.15 | 25.25 | 22.62 | 10.64 | 21.47 | |||||
| >70,000 | 44.72 | 59.9 | 71.95 | 85.96 | 66.63 | |||||
| Age, years | 7.87 (0.84) | 7.83 (0.72) | 7.87 (0.77) | 7.83 (0.73) | 7.85 (0.77) | |||||
| Neighborhood median household income, $ | 46,557.59 (17,005.33) | 54,033.61 (17,757.75) | 64,709.90 (18,974.18) | 69,697.94 (21,489.68) | 59,355.23 (21,004.38) | |||||
| Maternal intelligence score | 104.79 (16.44) | 106.08 (14.63) | 109.5 (13.52) | 112.97 (11.56) | 108.55 (14.37) | |||||
| Exposure to greenness at birth | 0.4 (0.12) | 0.52 (0.09) | 0.59 (0.12) | 0.62 (0.16) | 0.54 (0.15) | |||||
| Exposure to greenness at early childhood | 0.38 (0.08) | 0.53 (0.03) | 0.63 (0.02) | 0.72 (0.04) | 0.57 (0.14) | |||||
| Exposure to greenness at mid-childhood | 0.46 (0.14) | 0.57 (0.08) | 0.64 (0.07) | 0.72 (0.07) | 0.6 (0.13) | |||||
| Mediators | ||||||||||
| Air pollution (black carbon) exposure | 0.72 (0.16) | 0.57 (0.14) | 0.49 (0.11) | 0.43 (0.12) | 0.55 (0.17) | |||||
| Physical activity, hours per day | 2.8 (1.64) | 2.72 (1.55) | 3.05 (1.62) | 2.95 (1.61) | 2.89 (1.61) | |||||
| Cognition measures at early childhood | ||||||||||
| Vocabulary | 101.81 (14.93) | 104.26 (13.87) | 105.16 (13.2) | 107.4 (13.04) | 104.88 (13.81) | |||||
| Motor abilities | 101.8 (11.33) | 103.03 (11.08) | 102.57 (10.15) | 103.43 (11.04) | 102.77 (10.88) | |||||
| Cognition measures at mid-childhood | ||||||||||
| Verbal intelligence score | 109.87 (16.4) | 113.66 (13.28) | 114.36 (12.98) | 116.97 (12.16) | 113.87 (13.92) | |||||
| Nonverbal intelligence score | 104.85 (17.59) | 108.23 (15.67) | 106.85 (16.25) | 109.59 (16.43) | 107.46 (16.55) | |||||
| Visual-motor abilities | 93.62 (17.86) | 90.2 (15.04) | 92.86 (17.52) | 95.28 (16.79) | 93.07 (16.92) | |||||
| Visual memory | 16.09 (4.64) | 17.34 (4.22) | 17.06 (4.41) | 17.78 (4.21) | 17.1 (4.4) | |||||
Abbreviations: NDVI, normalized difference vegetation index; SD, standard deviation.