Table 7.

Linear regression for the dependent variables Co, Cu, As, Pb and Zn (µg/L) (after logarithmic transformation) in the exposed workers, internal control and external control groups

Other independent variables considered in the models that resulted not significant: Residence area (ref. urban); Alcohol consumption (units/week); Overall time spent in urban traffic in the last 48 hours before urine collection (minutes); Presence of fast roads within 500 m of the residence (ref. no)

*non smokers: urinary cotinine >200 ng/ml

ns=not significant