Table 1

Selected investigations of associations between passive smoking, chronic respiratory symptoms, and self-reports of doctor-diagnosed asthma, chronic bronchitis and emphysema

Reference no.	Study population	Study period	Exposure assessment		Other exposures	Outcome	Results
Reference no.	Study population	Study period	Periods	Location	Other exposures	Outcome	Results
34	Adventist Health Study, (n = 3914), ⩾25 years of age	1977–87	Childhood and adulthood		Home and work	Outdoor TSP, past smoking	Symptoms and doctor-diagnosed asthma, chronic bronchitis, emphysema	Childhood exposure only
								RR = 1.1 (95% CI 0.7 to 1.7)
								Childhood and past adult exposure
								RR = 1.7 (95% CI 1.3 to 2.2)
								Childhood and current adult exposure
								RR 2.0 (95% CI 1.2 to 3.2)
35	Philadelphia, 219 non-smokers with self-report of obstructive respiratory disease, 657 controls	1985–86	Adulthood		Home	—	Doctor-diagnosed asthma, chronic bronchitis, or emphysema	Passive smoking:
								<1 ppd, OR = 1.2 (95% CI 0.8 to 1.7)
								⩾1 ppd, OR = 1.9 (95% CI 1.2 to 2.9)
23	Eight areas in Switzerland, (n = 4197), 18–60 years of age	—	Past 12 months		Home and work	—	Self-reports of symptoms and diagnosis	Passive smoking:
								Wheezing, OR = 1.9 (95% CI 1.4 to 2.7)
								Chronic bronchitis, OR = 1.7 (95% CI 1.3 to 2.2)
								Dyspnoea, OR = 1.5 (95% CI 1.2 to 1.8)
								Doctor-diagnosed asthma, OR = 1.4 (95% CI 1.0 to 1.9)

TSP = total suspended particulates.