TABLE 3.
Associations Between Hazardous Air Pollutants and Autism Spectrum Disorder From Hierarchical Semi-Bayes Modelsa,b by Urban/Rural Classification and State
| Urban/Rural |
State |
||||||
|---|---|---|---|---|---|---|---|
| Unit Changec (ng/m3) |
100% Rural | Mixed | 100% Urban | NC | WV | All | |
| No. Children | 881 | 1446 | 850 | 1931 | 1246 | 3177 | |
| No. Cases | 89 | 177 | 108 | 201 | 173 | 374 | |
| OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | ||
| Acetaldehyde | 756 vs. 238 | 1.3 (0.6–2.9) | 1.3 (0.5–3.6) | 0.8 (0.3–2.4) | 1.4 (0.5–4.1) | 1.0 (0.5–2.1) | 1.1 (0.6–2.3) |
| Acrolein | 109 vs. 53 | 1.2 (0.6–2.5) | 1.4 (0.7–2.6) | 0.9 (0.5–1.9) | 1.3 (0.7–2.7) | 1.2 (0.6–2.2) | 1.2 (0.7–2.1) |
| Acrylonitrile | 1.4 vs. 0.2 | 0.9 (0.4–2.0) | 1.0 (0.5–2.4) | 0.8 (0.3–2.5) | 0.6 (0.2–2.4) | 1.0 (0.5–1.8) | 0.8 (0.5–1.5) |
| Arsenic compounds | 0.21 vs. 0.03 | 0.9 (0.5–1.6) | 1.2 (0.8–1.8) | 0.9 (0.2–4.3) | 0.9 (0.3–2.9) | 0.9 (0.7–1.3) | 1.0 (0.8–1.3) |
| Benzene | 1438 vs. 742 | 1.1 (0.6–2.0) | 1.0 (0.5–1.8) | 1.0 (0.5–1.9) | 1.0 (0.5–1.9) | 0.9 (0.5–1.6) | 0.9 (0.5–1.6) |
| Beryllium compounds | 0.031 vs. 0.003 | 0.6 (0.1–2.5) | 1.6 (0.4–5.9) | 2.1 (0.4–11) | 1.1 (0.3–4.9) | 0.9 (0.2–4.6) | 0.9 (0.4–2.1) |
| 1,3-Butadiene | 79 vs. 18 | 1.1 (0.4–3.2) | 1.7 (0.7–4.3) | 1.0 (0.3–3.6) | 1.6 (0.5–4.8) | 1.4 (0.6–3.4) | 1.5 (0.7–3.3) |
| Cadmium compounds | 0.07 vs. 0.01 | 1.2 (0.4–3.5) | 0.8 (0.4–1.9) | 1.2 (0.3–4.7) | 1.2 (0.4–3.2) | 0.6 (0.3–1.6) | 1.1 (0.6–2.0) |
| Chloroform | 90 vs. 83c | 1.0 (0.9–1.1) | 1.0 (0.9–1.1) | 1.0 (0.9–1.1) | 1.0 (0.9–1.1) | 1.0 (0.9–1.1) | 1.0 (0.9–1.1) |
| Chromium compounds | 3.4 vs. 0.2 | 1.1 (0.3–4.2) | 1.4 (0.5–4.4) | 0.7 (0.1–3.6) | 0.7 (0.2–2.9) | 2.0 (0.7–5.4) | 1.2 (0.6–2.5) |
| Coke oven emissionsb | Any vs. none | 1.4 (0.7–2.7) | 0.9 (0.5–1.7) | 1.8 (0.8–4.2) | NE | 1.2 (0.8–1.7) | 1.2 (0.8–1.8) |
| 1,3-Dichloropropene | 71 vs. 14 | 1.7 (0.5–6.4) | 1.8 (0.5–5.9) | 0.9 (0.2–3.5) | 1.2 (0.3–4.2) | 1.7 (0.5–5.2) | 1.9 (0.8–4.8) |
| Diesel particulate matter | 1844 vs. 1025 | 0.9 (0.5–1.6) | 1.0 (0.7–1.6) | 0.9 (0.6–1.5) | 1.1 (0.6–1.9) | 1.0 (0.7–1.5) | 1.1 (0.8–1.5) |
| Ethylbenzene | 441 vs. 82 | 0.6 (0.1–2.3) | 1.2 (0.3–5.0) | 0.9 (0.2–4.2) | 1.5 (0.3–6.6) | 0.5 (0.1–2.0) | 0.7 (0.2–2.6) |
| Ethylene oxide | 8.4 vs. 0.5 | 0.8 (0.3–2.4) | 1.0 (0.5–2.1) | 1.0 (0.3–3.2) | 0.5 (0.1–1.9) | 1.2 (0.6–2.2) | 1.0 (0.6–1.6) |
| Formaldehyde | 1074 vs. 589 | 1.0 (0.6–1.7) | 1.0 (0.6–1.7) | 0.9 (0.5–1.7) | 1.1 (0.6–1.7) | 0.9 (0.5–1.5) | 0.9 (0.6–1.4) |
| Hexane | 523 vs. 120 | 1.4 (0.4–4.9) | 1.1 (0.3–3.3) | 1.0 (0.3–3.6) | 1.1 (0.3–4.2) | 0.9 (0.3–2.5) | 1.0 (0.4–2.8) |
| Hydrazine | 2.4 E-4 vs. 3.4 E-6 | 0.5 (0.2–1.1) | 0.8 (0.4–1.4) | 0.4 (0.1–1.3) | 1.0 (0.3–3.7) | 0.7 (0.4–1.1) | 0.6 (0.4–0.9) |
| Lead compounds | 3.1 vs. 0.3 | 0.9 (0.3–2.7) | 0.7 (0.3–1.5) | 0.3 (0.1–1.3) | 0.6 (0.2–1.5) | 0.9 (0.5–1.9) | 0.7 (0.4–1.1) |
| Manganese compounds | 7.1 vs. 0.4 | 1.2 (0.5–3.3) | 0.7 (0.3–1.6) | 0.6 (0.1–3.4) | 0.7 (0.2–2.6) | 0.8 (0.4–1.8) | 0.8 (0.4–1.4) |
| Mercury compounds | 0.3 vs. 0.1 | 1.2 (0.5–3.1) | 0.9 (0.4–2.2) | 1.0 (0.3–3.2) | 0.9 (0.4–2.2) | 1.1 (0.5–2.4) | 1.2 (0.7–2.1) |
| Methyl tert-butyl ether (MTBE) | 100 vs. 30 | 1.6 (0.7–3.6) | 0.8 (0.4–1.7) | 0.9 (0.4–2.3) | 0.9 (0.4–2.1) | 1.2 (0.6–2.2) | 0.9 (0.5–1.5) |
| Methylene chloride | 640 vs. 183 | 1.2 (0.4–3.3) | 1.2 (0.6–2.5) | 1.9 (0.8–4.7) | 1.5 (0.6–3.3) | 1.0 (0.4–3.0) | 1.4 (0.7–2.5) |
| Nickel compounds | 1.7 vs. 0.1 | 1.2 (0.4–3.4) | 0.9 (0.4–2.0) | 1.8 (0.6–4.9) | 0.8 (0.2–3.3) | 0.9 (0.4–1.8) | 1.1 (0.6–1.9) |
| Perchloroethylene | 271 vs. 155 | 1.1 (0.6–2.0) | 1.2 (0.7–2.0) | 1.0 (0.6–1.7) | 1.1 (0.7–1.9) | 1.1 (0.6–1.8) | 1.1 (0.7–1.7) |
| Polycyclic aromatic hydrocarbons group (PAH7) | 4.9 vs. 1.2 | 0.7 (0.2–3.2) | 0.3 (0.1–1.0) | 1.0 (0.5–1.9) | 0.9 (0.4–1.8) | 0.9 (0.2–3.6) | 0.7 (0.4–1.3) |
| Propionaldehyde | 208 vs. 56 | 1.2 (0.4–3.3) | 1.3 (0.5–3.6) | 1.1 (0.4–3.5) | 1.1 (0.4–3.4) | 1.2 (0.5–3.1) | 1.5 (0.6–3.6) |
| Propylene dichloride | 0.08 vs. 0.01 | 0.7 (0.2–3.2) | 0.9 (0.2–3.2) | 0.8 (0.2–3.9) | 0.8 (0.2–3.7) | 0.6 (0.2–2.4) | 0.8 (0.3–2.3) |
| Quinoline | 0.0051 vs. 0.0001 | 1.5 (0.7–3.3) | 1.1 (0.6–2.1) | 2.1 (0.8–5.6) | 2.1 (0.4–11) | 1.3 (0.8–2.1) | 1.4 (1.0–2.2) |
| Styrene | 41 vs. 5 | 0.8 (0.2–2.7) | 1.1 (0.5–2.8) | 2.0 (0.6–6.1) | 2.0 (0.6–6.9) | 1.6 (0.8–3.2) | 1.8 (1.0–3.1) |
| 1,1,2,2-Tetrachloroethane | 0.8 vs. 0.1 | 1.0 (0.2–5.6) | 1.2 (0.4–3.8) | 0.8 (0.2–3.5) | 0.7 (0.1–3.2) | 1.9 (0.5–7.3) | 1.2 (0.4–3.2) |
| Toluene | 3018 vs. 582 | 0.4 (0.1–2.8) | 0.3 (0.1–1.6) | 0.6 (0.1–3.5) | 0.5 (0.1–3.0) | 0.6 (0.1–3.4) | 0.4 (0.1–1.3) |
| Trichloroethylene | 129 vs. 85 | 1.1 (0.7–1.6) | 1.1 (0.8–1.5) | 1.0 (0.7–1.5) | 1.1 (0.8–1.5) | 1.0 (0.7–1.5) | 1.0 (0.8–1.3) |
| Vinyl chloride | 2.0 vs. 0.3 | 0.9 (0.3–3.3) | 0.8 (0.3–2.5) | 1.3 (0.3–5.0) | 0.8 (0.2–3.3) | 0.9 (0.4–2.4) | 0.9 (0.4–2.0) |
| Xylenes | 1935 vs. 505 | 1.0 (0.3–4.2) | 1.4 (0.4–4.9) | 0.7 (0.2–2.7) | 1.3 (0.3–4.9) | 0.9 (0.3–3.1) | 1.1 (0.4–3.4) |
The semi-Bayes estimates arise from a model including all HAPs except for coke oven emissions and a priori confounders race (non-Hispanic white, black, other), maternal education (<HS, HS, college), maternal age (quadratic splines with 3 knots), smoking in pregnancy (yes, no), marital status, census tract median household income (quadratic splines with 3 knots), and urbanicity (quadratic splines with 3 knots) and also include a second-stage model with a pre-specified residual variance in estimates (τ2) of 0.209 (6-fold range) and exchangeability predictors of known human developmental neurotoxicant, placental transfer, confidence level in HAP model estimates, and similarity between outdoor and indoor concentrations.
Coke oven emissions were not correlated with any other HAP and so were not adjusted for other HAPs or included in semi-Bayes models.
Unit change corresponds to the 80th percentile versus 20th percentile among controls for both states combined, except for chloroform which exhibited low variability and for which we compared the 95th versus the fifth percentile.
NE indicates not estimable.