Table 1 Characteristics of the study population unit: mean±SD, number (%)

Age

42.1±9.1^a

47.3±6.8^b

39.8±8.0^a

44.0±10.5^a

38.8±11.5^a

<0.000^‡

Work duration

14.4±11.9^a

24.5±7.3^b

14.0±7.5^a

14.5±9.3^a

15.1±11.6^a

<0.000^‡

BMI^†

23.9±2.9^a

22.7±3.5^a

23.2±3.2^a

24.2±2.9^a

24.1±3.8^a

0.002^‡

Smoking

No

30(24.0)

32(39.0)

14(16.7)

73(28.4)

15(33.3)

0.017^§

Yes

95(76.0)

50(61.0)

70(83.3)

184(71.6)

30(66.7)

Alcohol drink frequency per week

2.03±1.44^a

1.65±1.53^a,b

1.96±1.54^a

1.95±1.62^a

1.31±1.34^b

0.046^‡

Blood Lead(μg/dl)

-

-

-

8.33±5.18

6.12±4.30

0.012^∥

Urine hippuric acid

-

0.57±0.58^a

0.28±0.36^b

-

0.37±0.54^b

0.001^‡

Urine methyl hippuric acid

-

0.04±0.10^a

0.14±0.17^b

-

0.07±0.12^a

<0.000^‡