Table 3

Recommended questions for studies assessing secondhand smoke exposure (SHSe)

Question	Location	Source	Reliable^*	Validation air^*	Validation biomarker^*
Lifetime
Number of years living with a smoker	Home	Mother	Yes
Adulthood
Living with a regular smoker (yes/no)	Home	Wife	Yes
		Husband	Yes
		Mother	Yes
No. of years sharing the home with smoker(s)	Home	Spouse	Yes
No. of years sharing the home with smoker(s)	Home	Other HM	Yes
No. of pack-years of SHSe (number of cigarette packs smoked per day by the source × number of years the source has smoked)	Total	Parents	Yes
	Total	All HM	Yes
No. of cigarettes smoked	Home	All smokers		Nicotine/particulate matter
No. of cigarettes smoked	Work	All smokers		Nicotine
No. of smokers	Work	All smokers		Nicotine/particulate matter	Saliva cotinine
No. of hours of SHSe	Work	All smokers		Nicotine/particulate matter	Urine cotinine
No. of hours of exposure × no. of smokers × proximity to the participant	Total	All smokers		Nicotine
Childhood (past)
SHSe during childhood (yes/no)	Total	Mother	Yes
SHSe during childhood (yes/no)	Total	Father	Yes
SHSe while mother was pregnant (yes/no)	Total	Mother	Yes
No. of years sharing the home with smoker(s)	Home	Mother	Yes
		Father	Yes
		Other HM	Yes
No. of hours per day of SHSe	Total	Father	Yes
No. of hours per day of SHSe	Total	Other HM	Yes
No. of pack-years of SHSe	Total	Parents	Yes
No. of pack-years of SHSe	Total	All HM	Yes
Pregnant women (third trimester)
Hours of woman's SHSe at home	Home	All HM			Cord blood cotinine
Cigarettes per day smoked in their presence	Home	All HM			Cord blood cotinine
Cigarettes per day smoked in their presence	Home or work	All HM and coworkers			Cord blood cotinine
Childhood (current)
Smoking status of parent	Total	Mother			Saliva cotinine
Smoking status of parent	Total	Father			Saliva cotinine
Hours of child's SHSe at home	Home	All smokers		Nicotine^†
Cigarettes per day smoked	Total	Mother	Yes		Plasma cotinine
Cigarettes per day smoked	Total	All HM			Plasma cotinine
Cigarettes per day smoked in the home	Home	Mother	Yes		Urine cotinine
		Parents	Yes		Urine cotinine/hair nicotine
		All HM			Urine cotinine
		All HM and visitors			Urine cotinine
		All smokers			Hair nicotine
Cigarettes per day smoked in the presence of the child	Home	All smokers	Yes		Urine cotinine^†
Cigarettes per day smoked in the presence of the child	Total	All smokers			Hair nicotine
No. of cigarettes smoked	Total	Mother		Nicotine
No. of cigarettes smoked in the home	Home	All smokers		Nicotine	Urine cotinine
No. of cigarettes smoked in the home	Home	Mother			Urine cotinine
No. of cigarettes smoked in the presence of the child	Total	Mother		Nicotine
	Total	All smokers	Yes		Urine cotinine
	Home	Mother		Nicotine	Urine cotinine
	Home	Parents	Yes
	Car	Mother	Yes
Weekly no. of cigarettes smoked	Total	Mother			Urine cotinine
	Home	Mother	Yes	Nicotine
		Father	Yes
		Parents	Yes
Weekly no. of cigarettes smoked in the home in the presence of the child	Home	Mother	Yes
		Father	Yes
		Parents	Yes
		All smokers	Yes
Weekly no. of cigarettes smoked in the presence of the child	Total	All smokers	Yes
No. of smokers	Total	All HM			Hair nicotine/urine cotinine/serum cotinine
No. of smokers	Total	All HM and visitors			Urine cotinine
Cigarette butt counts in 24 h	Home	Mother			Urine cotinine
Cigarette butt counts × hours spent in living room	Home	Father			Urine cotinine

↵* κ ≥0.75 or correlation coefficient (r) ≥0.50.
↵† Reported by the smoking parent.
H, hair nicotine; HM, household members.