Many IEQ-improvement measures not addressed in this web site could be implemented; for example, reductions in indoor pollutant sources other than dampness and mold. Reductions in indoor tobacco smoking in homes may be a large opportunity. Also, the presented estimates have not considered some important reductions in adverse health outcomes, such as the reduced risk of cancer when indoor chemical pollutants are decreased through pollutant source control or increased ventilation. Finally, the IEQ improvement measures could be implemented in a broader range of buildings; for example, ventilation rates could be increased in homes, schools, or retail buildings.
A broad evaluation of the potential health benefits of improved IEQ is available for Europe . The benefits are expressed in units of disability-adjusted life years (DALYS), which are a measure of total disease burden accounting for adverse health effects, disability, and years of lost life. The health effect categories considered are allergy and asthma, cardiovascular disease, chronic obstructive pulmonary disease, lung cancer, sick building syndrome, infectious respiratory disease, and carbon monoxide poisoning. The indoor pollutant categories considered are combustion products, volatile organic compounds, radon, pathogens (e.g., virus and bacteria), and carbon monoxide. The analysis indicates that for Europe, with 2.4 times the U.S. population, the annual potential benefits are: 145,000 DALYS from fixing heating and combustion systems such as banning unvented appliances and using range hoods on all gas stoves; 898,000 DALYs from ventilation and air conditioning improvements including developing and applying health based ventilation rate guidelines and regular system maintenance; and 579,000 DALYs from improvements in water systems and moisture management including building design and maintenance to prevent dampness, exhaust ventilation in kitchen, bath and laundry rooms, and avoiding buildings and building features that do not dry as a result of airflows. These are estimates of the maximum potential health benefits, not the practically-achievable benefits. They should not be summed, because of overlaps in the benefits projected from the different IAQ-improvement measures. A large portion of the avoided DALYs associated with ventilation and air conditioning improvements result from reduced exposures to outdoor air pollutants, especially particulate matter. No analogous estimates are available for the United States.