Table 1.

Demographic characteristics (means), income, employment, on the job exposure to vehicle exhaust (number), and biomarker levels (means) of study populations.

	Urban Background	Near Highway	p
Demographic characteristics
Age (years)	53.7	54.7	0.79
Height (males, cm)	178.9	173.4	0.59
Weight (males, kg)	87.3	82.9	0.77
Height (females, cm)	166.9	157.7	0.38
Weight (females, cm)	69.6	72.8	0.38
Annual income			< 0.001
1 (<25,000)	1	4
2 (25,000–49,999)	0	7
3 (50,000–74,999)	2	7
4 (≥75,000)	13	1
Highest Degree			< 0.001
1 (did not complete high school)	1	1
2 (completed high school)	1	9
3 (completed junior college)	1	1
4 (completed college)	7	7
5 (completed graduate school)	10	2
Work status			0.08
1 (working full-time)	13	7
2 (working part-time)	2	7
3 (Unemployed)	0	2
4 (retired)	4	3
5 (disabled)	1	0
Exposure to vehicle exhaust at work (excludes 10 non-working subjects)			<0.01
1 (multiple hours per day)	1	4
2 (daily for less than one hour)	0	3
3 (once per week)	0	2
4 (once per month)	0	0
5 (never)	16	7
Total cholesterol (mg/dl)	144 (154)	175 (176)	0.11
Triglyceride (mg/dl)	50 (78.8)	53 (79.1)	0.91
LDL (mg/dl)	82 (92)	110 (113.3)	0.046
HDL (mg/dl)	43 (45.4)	41 (43.9)	0.87
Fibrinogen (mg/dl)	421.3 (422.7)	396.2 (418.3)	0.70
CRP (mg/L)	0.9 (1.1)	1.2 (3.4)	0.14