Table 2 Demographic characteristics of the study population by lead quartile subsets.
| Total (n = 449) | Blood lead quartile | p Value | ||||
|---|---|---|---|---|---|---|
| Quartile 1 (n = 112) | Quartile 2 (n = 113) | Quartile 3 (n = 113) | Quartile 4 (n = 111) | |||
| Blood lead level, μg/dl (mean (range)) | 22.7 (2.0–66.9) | 8.7 (2.0–13.2) | 16.9 (13.3–20.4) | 24.8 (20.6–29.4) | 40.4 (29.7–66.9) | |
| Homocysteine, μmol/l (mean (SD)) | 7.8 (3.3) | 7.2 (2.8)* | 8.1 (3.0) | 7.5 (2.7) | 8.5 (4.3)* | 0.022 |
| Age, years (mean (SD)) | 38.7 (10.7) | 39.9 (9.9) | 39.7 (11.0) | 37.5 (11.7) | 37.5 (9.7) | 0.153 |
| Exposure duration, years (mean (SD)) | 12.9 (9.8) | 14.1 (9.8) | 13.1 (9.9) | 11.9 (9.9) | 12.3 (9.1) | 0.375 |
| Race/ethnicity (%) | ||||||
| Vietnamese | 21.6 | 23.3 | 22.9 | 25.6 | 28.2 | |
| Chinese | 9.6 | 46.5 | 32.3 | 18.2 | 3.0 | |
| Malay | 8.7 | 6.8 | 20.5 | 34.1 | 38.6 | |
| Indian | 60.1 | 2.5 | 27.5 | 30.0 | 40.0 | |
| Current cigarette use (%) | ||||||
| Smoker | 49.8 | 54.5 | 47.8 | 49.6 | 46.4 | |
| Non‐smoker | 50.2 | 45.5 | 52.2 | 50.4 | 53.6 | |
| Alcoholic beverage use (%) | ||||||
| None | 23.0 | 33.3 | 16.8 | 28.3 | 11.8 | |
| Social drinker (<1 per week) | 44.9 | 37.8 | 51.3 | 41.6 | 48.2 | |
| Regular drinker (at least once a day) | 32.2 | 28.8 | 31.9 | 30.1 | 40.0 | |
*Significant difference (p = 0.03) one‐way ANOVA.