Comparative progression of atherosclerosis in ApoE-/- mice exposed to environmental tobacco smoke and concentrated ambient particles

There are many similarities in the nature and extent of the risks that have been associated with the inhalation of environmental tobacco smoke (ETS) and ambient air fine particulate matter (PM2.5). Both of these complex mixtures affect lung growth in children, and elevate cardiovascular disease and lung cancer in adults. In this study, we exposed ApoE knockout mice to ETS at a concentration of 450 mu g/m(3) for 6 hr/day, 5 day/wk, for 6 months. Our results showed that intermittent long-term exposure to this relatively low concentration of ETS significantly exacerbated atherosclerosis lesion progression and reduced the survival in atherosclerosis susceptible mice. Using ultrasound biomicroscopy, side stream smoke significantly exacerbated plaque progression at 4 months after the start of exposure. These results were comparable to that produced in a similar mouse model exposed to the same regimen of concentrated ambient particles at an average concentration of 85 mg/m(3).