Table 5.

Analysis of benzene classified into quartiles at the census tract of the birth residence and acute leukemia by year of birth. Estimates are presented as odds ratios (OR) and 95% confidence intervals (CI). Statistically significant estimates are indicated in bold.

Year of Birth	All Years	1979-1989	1990-1994	1995-1999	2000-2004	2005-2010
Number of Cases	307	34	45	67	102	59
Number of Controls	1013	102	142	216	355	198
	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)
Unadjusted
0.11-<0.39 μg/m³	Reference	Reference	Reference	Reference	Reference	Reference
0.39-<0.67 μg/m³	0.97 (0.67, 1.41)	0.70 (0.22, 2.24)	1.03 (0.38, 2.81)	0.80 (0.36, 1.76)	1.16 (0.63, 2.15)	1.37 (0.48, 3.91)
0.67-<0.91 μg/m³	1.07 (0.73, 1.55)	0.87 (0.29, 2.55)	0.83 (0.28, 2.45)	0.74 (0.36, 1.52)	0.87 (0.45, 1.68)	3.15 (1.22, 8.13)
0.91-2.03 μg/m³	1.13 (0.78, 1.63)	0.62 (0.20, 1.90)	1.30 (0.51, 3.29)	0.75 (0.35, 1.60)	1.11 (0.59, 2.07)	3.53 (1.35, 9.27)
Adjusted for Urbanization and Maternal Education
0.11-<0.39 μg/m³	Reference	Reference	Reference	Reference	Reference	Reference
0.39-<0.67 μg/m³	1.06 (0.71, 1.58)	0.53 (0.16, 1.79)	1.70 (0.54, 5.28)	0.80 (0.34, 1.86)	1.15 (0.59, 2.25)	2.22 (0.67, 7.39)
0.67-<0.91 μg/m³	1.21 (0.79, 1.87)	0.63 (0.17, 2.32)	2.16 (0.58, 8.09)	0.77 (0.34, 1.75)	0.87 (0.40, 1.88)	5.70 (1.69, 19.26)
0.91-2.03 μg/m³	1.28 (0.83, 1.97)	0.39 (0.10, 1.56)	3.17 (0.96, 10.49)	0.70 (0.30, 1.65)	1.03 (0.49, 2.17)	6.73 (1.86, 24.40)
Adjusted for Maternal Education
0.11-<0.39 μg/m³	Reference	Reference	Reference	Reference	Reference	Reference
0.39-<0.67 μg/m³	0.98 (0.68, 1.43)	0.59 (0.18, 1.91)	1.12 (0.40, 3.17)	0.78 (0.35, 1.75)	1.18 (0.63, 2.19)	1.40 (0.49, 4.01)
0.67-<0.91 μg/m³	1.05 (0.72, 1.51)	0.80 (0.26, 2.50)	1.08 (0.34, 3.48)	0.75 (0.36, 1.57)	0.90 (0.46, 1.75)	3.22 (1.24, 8.39)
0.91-2.03 μg/m³	1.17 (0.81, 1.68)	0.50 (0.15, 1.69)	1.44 (0.54, 3.89)	0.68 (0.31, 1.50)	1.07 (0.56, 2.02)	3.60 (1.35, 9.55)