Table 4.

Regression model for association between ozone and work history variables and serum malondialdehyde level in welders (n = 43)

Independent variable	R Square	P-value	Linear formula
Ozone	0.122	0.05	MDA = 3.557 + 1.647 Ozone
Work history	0.54	0.001	MDA = 3.179 + 0.188 Experience
Ozone and work history	0.632	0.001	MDA = 2.773 + 0.183 Experience + 1.435 Ozone