Table 2.

Demographic characteristics and biomarker levels by ethnic group

Dominican (n = 66)African-American (n = 47)
Demographic variables% (n)% (n)
Sex (n = 66, 47)
 Female57.6 (38)53.2 (25)
 Male42.4 (28)46.8 (22)
Smoker in home (n = 66, 46)a
 Yes16.7 (11)37.0 (17)
 No83.3 (55)63.0 (29)
Child around smoker during 48 hours before urine collection (n = 63, 46)
 Yes23.8 (15)26.1 (12)
 No76.2 (48)73.9 (34)
Mother without a high school diplomab (n = 65, 47)
 Yes38.5 (25)38.3 (18)
 No61.5 (40)61.7 (29)
Mother received medicaid during pregnancyb (n = 66, 46)
 Yes90.9 (60)87.0 (40)
 No9.1 (6)13.0 (6)
Specific gravity adjusted urinary naphthol levelsGeometric mean (min–max); 95% CIGeometric mean (min–max); 95% CI
 1-Naphthol3,340 (329–138,000); (2,330–4,770)3,490 (78.0–161,000); (2,250–5,430)
 2-Naphtholc5,260 (200–132,000); (3,960–6,970)3,010 (147–17,000); (2,340–3,860)
 NAPHd10,800; 95% CI (8,210–14,200)7,660; 95% CI (5,440–10,800)
Unadjusted urinary naphthol levelsGeometric mean (Min–Max)Geometric mean (Min–Max)
 1-Naphthol2,970 (113–138,000)2,890 (82.0–67,700)
 2-Naphthol4,680 (246–52,900)2,470 (150–10,300)
Chromosomal aberrations% (n)% (n)
Translocation
 Yes16.7 (11)19.1 (9)
 No83.3 (55)80.9 (38)
Stable aberration
 Yes30.3 (20)31.9 (15)
 No69.7 (46)68.1 (32)
Mean aberration frequencyMean (SD)Mean (SD)
 Translocation0.072 (0.179)0.092 (0.233)
 Stable aberration0.148 (0.252)0.155 (0.299)
  • aProportion of children with smokers in the house between African-American and Dominican children differs by χ2, P = 0.02.

  • bData obtained during pregnancy.

  • cDifference in 2-naphthol levels (ln-transformed) between 2 ethnic groups is significant, P = 0.007; no other variables differed between the 2 ethnic groups.

  • dFor NAPH, only 95% CI values are given.