The effects of secondhand smoke exposure on HRCT findings among asbestos-exposed workers.
OBJECTIVE
There is evidence suggesting that secondhand smoke (SHS) exposure is causally linked to adverse respiratory effects. We examined the relations between the exposure to SHS and radiological signs in chest high-resolution computed tomography (HRCT).


METHODS
Asbestos-exposed workers (n=633) were imaged with HRCT, primarily to investigate potential occupational lung disease. After excluding current smokers, the study population included 361 ex- and 141 never-smokers. They answered a questionnaire on occupational exposures, smoking habits and SHS exposure. HRCT images were assessed for emphysema, ground-glass, irregular/linear and rounded opacities, honeycombing and several other signs. Regression analyses were adjusted for asbestos exposure, ex-smoking, age, body mass index and potential reader effect.


RESULTS
Due to missing data the multivariate analyses were restricted to 310 participants aged 47.5-87.0 years. Their lifetime SHS exposure ranged between 0 and 193.5 pack-years (mean 23.5), and exposure in the past 12 months 0-30 packs (0.43). Total (B=0.005, 95% confidence intervals (95% CI) 0.002-0.008, p=0.000) and workplace (B=0.006, 95% CI 0.003-0.009, p=0.001) cumulative SHS exposures were significantly related to ground-glass opacities. Total SHS exposure in the last 12 months (B=0.027, 95% CI 0.000-0.054, p=0.048) and workplace exposure (B=0.027, 95% CI 0.000-0.054, p=0.048) were also significantly related to ground-glass opacities. Positive effects of SHS were also detected on irregular/linear opacities.


CONCLUSIONS
SHS exposure in the last 12 months and over lifetime significantly increases ground-glass opacity in HRCT, suggesting an early or subclinical desquamative interstitial pneumonia/respiratory bronchiolitis. This study further supports that SHS has adverse effects on the lungs that can be detected by X-ray methods.
Vierikko
Tuula
T
The Department of Diagnostic Radiology, Tampere University Hospital, FI-33521 Tampere, Finland. tuula.vierikko@fimnet.fi
Järvenpää
Ritva
R
Uitti
Jukka
J
Virtema
Pauliina
P
Oksa
Panu
P
Jaakkola
Maritta S
MS
Autti
Taina
T
Vehmas
Tapio
T
D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000633:toxicity*; D001194:Asbestos / Q000633:toxicity*; D015992:Body Mass Index; D016022:Case-Control Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008168:Lung / Q000000981:diagnostic imaging*; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D012044:Regression Analysis; D012907:Smoking / Q000009:adverse effects; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed
D000393:Air Pollutants; D014028:Tobacco Smoke Pollution; D001194:Asbestos