. 2012 Jul 19;2(4):e001318. doi: 10.1136/bmjopen-2012-001318

Table 2.

Geometric means (and geometric standard deviations) of urinary analytes before and after 6 h of work by self-reported smoking status

Levels of urinary analytes (ng/l)	Before work (n=18)		After work (n=17)
Levels of urinary analytes (ng/l)	Non-smokers (n=10)	Smokers (n=8)	Non-smokers (n=9)	Smokers (n=8)
1-OH-naphthalene	672 (4)	1604 (3)	1978 (2)*	3395 (2)*
2-OH-naphthalene	1808 (2)	4316 (2)*	2670 (2)	6186 (2)* ‡
9-OH-phenanthrene	265 (4)	846 (2)*	713 (3)*	1572 (2)*
2-OH-fluorene	358 (3)	1495 (2)*	925 (3)*	2724 (2)* ‡
1-OH-pyrene	213 (3)	692 (2)*	498 (2)*	1002 (2)*
8-OHd-guanosine (μg/l)	8 (6)	12 (2)	29 (2)*	59 (2)* †

Using multiple comparisons: *p<0.05 when compared with non-smokers before work; †p<0.05 when compared with smokers before work; ‡p<0.05 when compared with non-smokers after work.