Americans spend an average of more than 65% of their time in their own home or others' homes, the health impacts of indoor air pollution has remained elusive.  Jennifer Logue, from Lawrence Berkeley National Lab (California, USA), and colleagues combined disease incidence and Disability Adjusted Life Years (DALYs)-based health impact models to estimate the population average health costs related to chronic inhalation of air pollutants in U.S. residences. The team used disease impact models and incidence to identify those indoor air pollutants with the greatest impacts on health. Acrolein, formaldehyde, and small particles of particulates accounted for most of the negative effects from indoor air pollutants.  Formaldehyde and acrolein had the largest estimated number of annual DALYs lost per 100,000 people of all the various indoor pollutants considered, at 46 and 47, respectively.  While the DALY losses associated with hospitalization were low for each pollutant, the estimated DALYs lost because of incidents of stroke, chronic bronchitis, and premature death related to PM(2.5) (fine particles in ambient air 2.5 micrometers or less in size) also was a contributor to the annual health impact, with the central estimate for disability adjusted life years lost due to all indoor air pollutants as 1,100 per 100,000 people.