exposure to outdoor aeroallergens and other air pollutants. Under these conditions,
many of the climate change related exposures and health effects are similar to what
have been documented and projected for outdoor-related climate change related
adverse health effects (NIEHS 2010, Ebi et al. 2008, Wilby 2007, MMWR 2006).
For instance, in a recent review of the expected effects of climate change on
respiratory allergic diseases, D’Amato and Cecchi (2008) highlight expected changes in
Europe that that may have negative, climate change related, health effects on atopic
individuals. These factors that include an earlier start of the pollen season, an extended
duration of the growing season, an increase in long distant transport of pollen and
pollution, and increased pollen production may be similar to climate change related
events in the United States. While there are still many factors to investigate regarding
climate change and the magnitude and duration of aeroallergen exposures, increases in
carbon dioxide, humidity, and rainfall will undoubtedly increase allergy-related
respiratory diseases in the indoor environment (Ariano et al. 2009, Schmier and Ebi
2009, D'Amato et al. 2007, Singer et al. 2005, Beggs 2004) as well as increase the
allergenicity of the pollen (Shea et al. 2008, D'Amato et al. 2007, Beggs and Bambrick
2005).
As mentioned above, increased air exchange rates impact exposures to outdoor
pollutants such as particulate matter. Over the past 10 years, research examining the
infiltration of pollutants from the outdoor air to the indoor environment has provided new
insights (e.g., Abt et al. 2000, Monn 2001) into the relative contribution of outdoor
sources. Researchers have discovered that fine particles (PM 2.5 ), which have the
greatest adverse health effects among the various particle size fractions, generally have
higher infiltration rates into homes as compared to coarse and ultra fine particles (UFP)
(Liu and Nazaroff 2003, Long et al. 2001, Liu and Nazaroff 2001) and can exceed
indoor-outdoor ratios of 0.5 (Meng et al. 2005, Wallace 1996). While UFPs have been
found to have lower infiltration rates as compared to PM 2.5 , indoor concentrations
generally follow outdoor concentrations and depending on the size fraction can have
indoor-outdoor ratios similar to those for PM 2.5 (McAuley et al. 2010, Nazaroff 2010).
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