Table 4.

Analysis of benzene classified into quartiles at the census tract of the birth residence and acute leukemia by age at leukemia diagnosis/index age for controls. Estimates are presented as odds ratios (OR) and 95% confidence intervals (CI).

Age at Leukemia Diagnosis/Index Age	All Ages	0–4 years	5–9 years	10–14 years	15–19 years
Number of Children	1320	663	326	147	184
	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)
Unadjusted
0.11-<0.39 μg/m3	Referent	Referent	Referent	Referent	Referent
0.39-<0.67 μg/m3	0.98 (0.68, 1.43)	0.92 (0.54, 1.58)	0.99 (0.46, 2.14)	1.45 (0.54, 3.89)	0.81 (0.28, 2.33)
0.67-<0.91 μg/m3	1.05 (0.72, 1.51)	1.22 (0.73, 2.05)	0.69 (0.32, 1.50)	1.22 (0.39, 3.88)	1.00 (0.38, 2.62)
0.91-2.03 μg/m3	1.17 (0.81, 1.68)	1.28 (0.76, 2.17)	1.26 (0.62, 2.56)	0.79 (0.27, 2.29)	0.95 (0.36, 2.51)
Adjusted for Urbanization and Maternal Education
0.11-<0.39 μg/m3	Referent	Referent	Referent	Referent	Referent
0.39-<0.67 μg/m3	1.06 (0.71, 1.58)	1.01 (0.56, 1.81)	1.07 (0.46, 2.44)	1.66 (0.53, 5.17)	0.71 (0.23, 2.19)
0.67-<0.91 μg/m3	1.21 (0.79, 1.87)	1.41 (0.77, 2.61)	0.76 (0.31, 1.88)	1.90 (0.44, 8.12)	0.96 (0.33, 2.82)
0.91-2.03 μg/m3	1.28 (0.83, 1.97)	1.45 (0.77, 2.73)	1.36 (0.59, 3.16)	1.15 (0.31, 4.24)	0.83 (0.27, 2.60)
Adjusted for Maternal Education
0.11-<0.39 μg/m3	Referent	Referent	Referent	Referent	Referent
0.39-<0.67 μg/m3	0.97 (0.67, 1.41)	0.92 (0.54, 1.58)	0.98 (0.45, 2.11)	1.35 (0.48, 3.75)	0.71 (0.23, 2.15)
0.67-<0.91 μg/m3	1.07 (0.73, 1.55)	1.25 (0.74, 2.10)	0.67 (0.31, 1.47)	1.37 (0.38, 4.95)	0.96 (0.36, 2.56)
0.91-2.03 μg/m3	1.13 (0.78, 1.63)	1.28 (0.75, 2.17)	1.21 (0.59, 2.48)	0.86 (0.28, 2.66)	0.83 (0.30, 2.33)