Demographic characteristics of participants in different exposure groups
| Demographic characteristics | No exposure | Indirect exposure | Direct exposure |
|---|---|---|---|
| *p<0.05; all other group differences are not statistically significant (p>0.10). | |||
| Sample size | 17 | 17 | 15 |
| Infant | |||
| Female (%) | 59 | 56 | 47 |
| Mean age (months) | 7.6 | 6.1 | 7.7 |
| Race/ethnicity (%) | |||
| African American | 18 | 6 | 19 |
| White non-Hispanic | 29 | 69 | 63 |
| Mexican American | 12 | 0 | 6 |
| Multiracial | 29 | 0 | 13 |
| Other | 6 | 19 | 0 |
| Mother | |||
| Race/ethnicity (%) | |||
| African American | 18 | 6 | 13 |
| White non-Hispanic | 41 | 69 | 75 |
| Mexican American | 18 | 0 | 0 |
| Multiracial | 12 | 0 | 6 |
| Other | 12 | 25 | 6 |
| Education level* | |||
| Did not complete high school | 18 | 0 | 13 |
| Completed high school | 12 | 44 | 44 |
| Technical/vocational school | 0 | 6 | 25 |
| Some college | 41 | 44 | 19 |
| Completed college | 35 | 6 | 0 |
| Employment status | |||
| Not employed | 71 | 81 | 56 |
| Part time (<40 hours | 12 | 6 | 25 |
| full-time (⩾40 hours) | 19 | 13 | 19 |
| Household | |||
| Total income (median) | $24000 | $21000 | $25000 |
| Size of residence (median, square feet) | 639 | 586 | 736 |
| Number residents (median) | 4 | 4.5 | 4 |