Indoor Air Pollutant Exposure for Life Cycle Assessment: Regional Health Impact Factors for Households

Human
exposure to indoor pollutant concentrations is receiving
increasing interest in Life Cycle Assessment (LCA). We address this
issue by incorporating an indoor compartment into the USEtox model,
as well as by providing recommended parameter values for households
in four different regions of the world differing geographically, economically,
and socially. With these parameter values, intake fractions and comparative
toxicity potentials for indoor emissions of dwellings for different
air tightness levels were calculated. The resulting intake fractions
for indoor exposure vary by 2 orders of magnitude, due to the variability
of ventilation rate, building occupation, and volume. To compare health
impacts as a result of indoor exposure with those from outdoor exposure,
the indoor exposure characterization factors determined with the modified
USEtox model were applied in a case study on cooking in non-OECD countries.
This study demonstrates the appropriateness and significance of integrating
indoor environments into LCA, which ensures a more holistic account
of all exposure environments and allows for a better accountability
of health impacts. The model, intake fractions, and characterization
factors are made available for use in standard LCA studies via www.usetox.org and in standard LCA software.