Table 1.
Descriptive statistics by proximity to lead mine: WLS graduates and siblings.
| Obser-vations | Full Sample (N = 8583) | Stratified by Exposure |
|||
|---|---|---|---|---|---|
| No Lead Mine (N = 8259) | Lead Mine (N = 324) | p value | |||
| Demographics | |||||
| Baseline Age, M ± SD | 8583 | 64.4 ± 3.8 | 64.4 ± 3.8 | 64.0 ± 3.8 | 0.052 |
| Female, N(%) | 8583 | 4601 (54) | 4427 (54) | 174 (54) | 0.971 |
| Childhood Variables | |||||
| Live in lead mining town, N(%) | 8583 | 324 (4) | |||
| Parents' Education, N(%) | 8496 | 0.783 | |||
| <12 years | 4318 (51) | 4163 (51) | 155 (49) | ||
| High school graduate | 2604 (31) | 2503 (31) | 101 (32) | ||
| Some college or more | 1574 (19) | 1513 (19) | 61 (19) | ||
| Log(parents' wages), M ± SD | 8151 | 5.0 ± 3.2 | 5.0 ± 3.1 | 2.8 ± 3.3 | <0.001 |
| Parents >$50 of non-wage income, N(%) | 8454 | 3382 (40) | 3164 (39) | 218 (69) | <0.001 |
| Rural, N(%) | 8583 | 4355 (51) | 4055 (49) | 300 (93) | <0.001 |
| Farm, N(%) | 8583 | 2570 (30) | 2374 (29) | 196 (60) | <0.001 |
| Southwest WI, N(%) | 8583 | 1563 (18) | 1239 (15) | 324 (100) | <0.001 |
| Adolescent IQ Z-Score, M ± SD | 8583 | 0.0 ± 1.0 | 0.0 ± 1.0 | −0.1 ± 1.1 | 0.081 |
| Adult Variables | |||||
| Education, N(%) | 8230 | 0.007 | |||
| High school or less | 4571 (56) | 4376 (55) | 195 (63) | ||
| Some college | 1360 (16) | 1327 (17) | 33 (10) | ||
| Bachelor's degree | 2299 (28) | 2216 (28) | 83 (27) | ||
| Net Worth, N(%) | 7637 | 0.328 | |||
| Q1 (≤76,000) | 1924 (25) | 1837 (25) | 87 (29) | ||
| Q2 (76,001 to 148,000) | 1906 (25) | 1837 (25) | 69 (24) | ||
| Q3 (148,001 to 290,000) | 1903 (25) | 1834 (25) | 69 (24) | ||
| Q4 (≥290,001) | 1904 (25) | 1837 (25) | 67 (23) | ||
| Fair/Poor Health, N(%) | 8579 | 862 (10) | 831 (10) | 31 (10) | 0.770 |
| Hypertension, N(%) | 8574 | 4160 (49) | 4018 (49) | 142 (44) | 0.085 |
| Heart Disease, N(%) | 8573 | 1300 (15) | 1269 (15) | 31 (10) | 0.004 |
| Cognitive Variables | |||||
| 2004 Memory/Attention Z-Score, M ± SD | 6638 | 0.0 ± 1.0 | 0.0 ± 1.0 | 0.0 ± 1.1 | 0.456 |
| 2011 Memory/Attention Z-Score, M ± SD | 5088 | −0.3 ± 0.8 | −0.3 ± 0.8 | −0.5 ± 0.9 | 0.002 |
| 2004 Language/Executive Z-Score, M ± SD | 8238 | 0.0 ± 1.0 | 0.0 ± 1.0 | −0.2 ± 0.9 | <0.001 |
| 2011 Language/Executive Z-Score, M ± SD | 6215 | −0.2 ± 0.8 | −0.2 ± 0.8 | −0.4 ± 0.8 | <0.001 |
Note: p-values derived from chi-squared tests (for categorical variables) or t-tests (for continuous variables. “Observations” column indicates the number of sample respondents who were not missing data for each variable before imputation.