Descriptive statistics for child-specific analysis variables (n=12 516 school districts with ≥100 children)
| Variable | Min. | Max. | Mean | SD |
| Proportion of (prop.) children | 0.030 | 0.620 | 0.238 | 0.041 |
| Prop. children in poverty | 0.000 | 0.930 | 0.190 | 0.126 |
| Prop. children in poverty squared | 0.000 | 0.865 | 0.052 | 0.066 |
| Prop. children that are foreign-born | 0.000 | 0.333 | 0.019 | 0.028 |
| Prop. children that have a disability | 0.000 | 0.444 | 0.044 | 0.030 |
| Prop. children that are black, non-Hispanic | 0.000 | 0.985 | 0.060 | 0.133 |
| Prop. children that are Hispanic (all races) | 0.000 | 0.993 | 0.130 | 0.185 |
| Prop. children that are Asian/Pacific Islander (API), non-Hispanic | 0.000 | 0.643 | 0.018 | 0.042 |
| Prop. children that are American Indian, non-Hispanic | 0.000 | 0.986 | 0.023 | 0.093 |
| Prop. children that are multiracial/other race, non-Hispanic | 0.000 | 0.332 | 0.034 | 0.026 |
| Prop. households with children that rent | 0.005 | 0.864 | 0.086 | 0.053 |
| Maximum total LCR | 10.930 | 826.309 | 35.076 | 14.692 |
| Maximum point LCR* | 0.000 | 776.801 | 1.347 | 8.081 |
| Maximum on-road mobile LCR* | 0.000 | 102.580 | 5.681 | 5.936 |
| Other descriptive statistics† | ||||
| Total population (all ages) | 282 | 8 175 133 | 24 915 | 115 893 |
| Total child population (<18) | 100 | 1 768 111 | 5989 | 26 579 |
| Area in km2 | 0.32 | 231 745.81 | 707.48 | 3708.92 |
*The minimum values for point and on-road are 0.000001. 0.000001 was added to all values to transform the few 0 values into very low values, which allowed for those school districts to be included in the models. An alternative approach is to remove those school districts, but a sensitivity analysis revealed that the two approaches are equivalent so we chose to keep all districts in the analysis.
†These variables were not included in the multivariate analysis but are included here for descriptive purposes.
LCR, lifetime cancer risk.