Table 3.

Exposure-response between exhaled CO at the end of the working day and CO in ambient air

	2 last hours AmbCO			4 last hours AmbCO			6 last hours AmbCO
	βa	βb	p	βa	βb	p	βa	βb	p
exhCO at the end of the shift	0.31	0.34	< 0.001	0.20	0.22	< 0.001	0.13	0.14	0.01
Exposure to tobacco smoke		0.12	0.17		0.17	0.27		0.11	0.54
Exposure to biomass		0.07	0.08		0.09	0.13		0.19	0.10
Any comorbidities		0.11	0.14		0.12	0.14		0.09	0.14
Abnormal lung function		0.01	0.25		0.03	0.20		0.05	0.18
Marital status		0.02	0.28		0.01	0.21		0.04	0.16

ambCO ambient carbon monoxide, exhCO exhaled carbon monoxide

^acrude values

^badjusted values