INTRODUCTION
When it comes to climate change, the only certainty is uncertainty. As pointed out
by the Intergovernmental Panel on Climate Change (IPCC), there are many speculative
predictions about the timing, magnitude, and patterns of climate change. Nonetheless,
the IPCC (2007) states that warming of the climate system is indisputable and based on
current practices green house gas emissions are expected to grow. Ebi et al. (2008)
noted that the impact of climate change will vary on a regional basis in the United
States. It follows that the impacts of climate change on indoor air will also vary by
region. The indoor air of homes, as well as other built structures, is often directly, or
indirectly, affected by environmental conditions outside the structure. Since adults, as
well as children, spend the majority of their time indoors (Klepeis et al. 2001; Field et al.
1998; Wiley et al. 1991), concentrations of pollutants within a home significantly
contribute to overall exposures. Indoor air quality often reflects outdoor air quality. In
addition, indoor air quality will also be impacted indirectly by changes in the occupant’s
behavior (as the occupant adapts to climate change) that will affect the production and
persistence of pollutants (e.g., carbon dioxide, nitrogen oxides, sulphur oxides,
aldehydes, lead, volatile organic compounds, semivolatile organic compounds,
biological pollutants, etc.) generated within the home or building. For example,
behavioral changes that reduce air exchange rates, such as the use of a room air
conditioner in a home with low air exchange rates, often results in higher concentrations
of indoor air pollutants than what exists outdoors.
CHANGES IN RESIDENTIAL VENTILLATION PATTERNS
Extension of growing season and moderate weather
Longer spring and fall warm temperate periods will extend the time periods
windows may be kept open, especially in northern regions of the United States or
among lower income individuals, resulting in increased air exchange rates that will
translate into more outdoor aeroallergens and other air pollutants (e.g., ozone,
particulate matter, etc.) equilibrating with the residential air. Increased use of window or
whole house fans that increase the air exchange rates of the home will also increase
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