Severity of Respiratory Symptoms: A Multivariable Analysis of SHS Exposure

Introduction: This study seeks to: 1) characterize participant secondhand smoke (SHS) exposure; and 2) Identify whether there is an association between biological and self-reported SHS exposure measures and respiratory symptomatology.

Methods: A telephone interview assessing a range of self-reported SHS exposure sources and respiratory symptoms was completed in 279 biologically confirmed non-smoker adults recruited from the 2011-2012 Florida Behavioral Risk Factor Surveillance System. Participants provided by mail hair and saliva samples for determination of nicotine and cotinine levels. A factor analysis of 14 respiratory symptom items identified three dimensions which served as dependent variables in multivariable regression modeling: chest symptoms (i.e. coughing); mucus accumulation symptoms (i.e. phlegm); and nasal symptoms (i.e. runny nose), with alpha reliabilities ranging from 0.67-0.88. Multivariable modeling was done for the three dimensions. 

Results:  Sixty-five percent of participants reported SHS exposure during the previous 7 days, 27% of participants had saliva cotinine levels indicating recent exposure to SHS, and 60% of participants had hair nicotine levels indicating longer-term exposure. Severity of chest symptoms was significantly associated with cotinine levels and self-reported exposure in public indoor places and restaurants (p’s<0.05). Severity of mucus accumulation symptoms was significantly associated with saliva cotinine levels and self-reported exposure inside of a car (p’s<0.05). Severity of nasal symptoms is significantly associated with self-reported exposure in public indoor places and restaurants (p<0.05).

Conclusions: Salivary Cotinine as opposed to hair nicotine levels were more consistently associated with respiratory symptoms. SHS exposure in public places significantly impacts the respiratory health. Policies regulating tobacco use in public venues may lead to reduced health effects.