Pulmonary responses in current smokers and ex-smokers following a two hour exposure at rest to clean air and fine ambient air particles

Background: increased susceptibility of smokers to ambient pm may potentially promote development of copd and accelerate already present disease.objectives: to characterize the acute and subacute lung function response and inflammatory effects of controlled chamber exposure to concentrated ambient fine particles (cafp) with mmad ≤ 2.5 microns in ex-smokers and lifetime smokers.methods: eleven subjects,aged 35-74 years,came to the laboratory 5 times; a training day and two exposure days separated by at least 3 weeks,each with a post-exposure visit 22 h later. double-blind and counterbalanced exposures to clean air (mean 1.5 ± 0.6 μg/m3) or cafp (mean 108.7 ± 24.8 μg/m3 ) lasted 2 h with subjects at rest.results: at 3 h post-exposure subjects' dtpa clearance half-time significantly increased by 6.3 min per 100 μg/m3 of cafp relative to clean air at 22 h post-exposure they showed significant reduction of 4.3% per 100 μg/m3 in fev1 and a significant dlco decrease by 11.1% per 100 μg/m3 of cafp relative to clean air at both 3 h and 22 h the hdl cholesterol level significantly decreased by 4.5% and 4.1%,respectively. other blood chemistries and markers of lung injury,inflammation and procoagulant activity were within the normal range of values at any condition.conclusions: the results suggest that an acute 2 h resting exposure of smokers and ex-smokers to fine ambient particulate matter may transiently affect pulmonary function (spirometry and dlco) and increase dtpa clearance half-time. except for a post exposure decrease in hdl no other markers of pulmonary inflammation,prothrombotic activity and lung injury were significantly affected under the conditions of exposure. © 2013 hazucha et al.; licensee biomed central ltd.