TABLE 3—

Associations Between Exposure to Workplace Secondhand Smoke and Level of Total NNAL, Nicotine, and Cotinine in the Postworkshift Urine of Nonsmoking Food Service Workers: Oregon, November 2004–August 2005

	No.a	Range of Levels (Untransformed)b	Mean Level (SD) (Untransformed)	Multiplicative Increase (95% CI)c
Total NNAL (pmol/mL)
Protected workers (reference)	31	0.01–0.18	0.02 (0.03)	1.00
Exposed workers	50	0.01–0.31	0.04 (0.05)	2.85d (1.77, 4.60)**
Total nicotine (ng/mL)
Protected workers (reference)	32	1.00–7.22	1.39 (1.33)	1.00
Exposed workers	52	1.00–319.00	44.36 (61.25)	15.12 (8.37, 27.33)**
Total cotinine (ng/mL)
Protected workers (reference)	32	1.00–5.35	1.4 (0.99)	1.00
Exposed workers	52	1.00–72.80	20.20 (18.27)	10.52 (6.90, 16.04)**

Notes. NNAL = 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol; SD = standard deviation; CI = confidence interval.

^aTotal NNAL (pmol/mL) could not be determined in 3 participants’ urine samples.

^bA value of half the limit of detection was used for nondetectable values. Limit of detection: cotinine, 2 ng/mL; nicotine, 2 ng/mL; NNAL, 0.007–0.01 pmol/mL depending on recovery.

^cBy exposure status. Multiplicative increase was based on linear regression and adjusted for participant age, gender, and exposure to secondhand smoke outside the workplace.

^dInterpretation: Being exposed to workplace secondhand smoke was significantly associated with an almost 300 percent increase in the level of total urinary NNAL.

** P < .001.