27 In their study, Tsai et al28 found that vehicle selleck kinase inhibitor exhaust significantly influenced the total PAH exposure (11.4 ��g/m3). Urinary 1- hydroxypyrene levels in both mechanics and fuel attendants (3.02 ug/mol creatinine) at a Taiwan highway toll station were significantly higher than those of controls (0.41 ug/mol creatinine).28 In 2003, Bartimaeus and Jacobs showed that considerable exposure to petrol or its products over a long period of time could cause nephrotoxicity in motor mechanics.29 Kuusimaki et al30 found high concentrations of 1-hydroxypyrene in bus-garage workers and waste collectors (0.125 ��g mol/mol creatinine) when compared with controls (0.055 ��g mol/mol creatinine).31 Autrup et al reported higher urinary 1- hydroxypyrene level for suburban/rural bus drivers (0.25 ��g mol/mol creatinine).

32 Burgaz et al have reported a higher urinary 1-hydroxypyrene levels in taxi drivers (0.57 ��g mol/mol creatinine).33 Other researchers have also reported higher urinary 1- hydroxypyrene in professional drivers (0.181 ��g mol/mol creatinine) and commercial drivers (0.263 ��g mol/mol creatinine).33 From our findings, none of the three personal factors (age, work experience, and smoking habit) had a significant effect on predicting urinary 1- hydroxypyrene level in the different occupations. The highest concentration of 1-OHP was recorded in a 28-year-old fuel attendant with just 8 years working experience and no smoking history (Table 3) while a 60-year-old subject with 40 years exposure had no trace of urinary 1-hydroxypyrene.

Smoking is the most widely studied confounder of environmental and occupational PAH exposure studies and the most preventable risk factor for lung cancer,34 coronary heart disease,35 and chronic obstructive pulmonary disease.36 Overall, our study showed no significant correlation between cigarette smoking and increased urinary 1-hydroxypyrene of all three occupations. In this study, 1-hydroxypyrene was detected in only 20% of smokers. Several researchers found cigarette smoking to be correlated with an elevated urinary 1-hydroxypyrene. Merlo et al37 found that the average urinary 1-hydroxypyrene for smoking traffic officers (0.201 ��g mol/mol creatinine) was higher than their non-smoking counterparts (0.102 ��g mol/ mol creatinine) and Chuang et al reported that smoking office employees also had higher 1-OHPY levels (0.179 ��g mol/mol creatinine) when compared with their non-smoking counterparts (0.067 ��g mol/ mol creatinine).31 Ichiba et al38 reported a decrease in urinary 1-hydroxypyrene and 2-naphthol after smoking cessation. A study by Carmella and co-workers in 200939 also showed that smoking cessation among 17 Brefeldin_A smokers at various times corresponded to a decrease in their 1-hydroxypyrene concentrations.