A cross-sectional study of secondhand smoke exposure and respiratory symptoms in non-current smokers in the U.S. trucking industry: SHS exposure and respiratory symptoms

Table 1 Characteristics and SHS exposure of 1,562 non-current smoking workers in the U.S. unionized trucking industry

Continuous variables	Median (IQR)
Age (years)	54 (48–61)
BMI (kg/m²)	29.0 (25.8-31.3)
Total years lived with smokers (years)	20 (7–30)
Pack-years of active smoking*	15 (5–30)
Years since quit smoking*	22 (17–30)
Categorical Variables	N	(%)
Male	1331	85.2
Caucasian	1404	89.9
Former smoker	692	44.3
Job title
Terminal worker	203	13.0
Driver	791	50.6
Office worker	228	14.6
Retired	308	19.7
Region of Residency
South	494	31.6
West	278	17.8
Midwest	521	33.4
Northeast	269	17.2
Living in urban area	1034	66.2
Exposed to SHS in the past 7 days	990	63.4
Current SHS exposure
Recent home exposure	158	10.4
Recent workplace exposure	413	30.6
Recent recreational exposure	1127	80.5
Childhood SHS exposure	1077	70.1
Respiratory symptoms
Chronic cough	153	9.8
Chronic phlegm	183	11.7
Any wheeze	718	47.8
Any symptom	793	50.8

IQR = interquartile range; BMI = body mass index.
* Among never smokers and former smokers who quit at least 10 years before completing the questionnaire.

ISSN: 1471-2458