title: Quantifying uncertainty in health impact assessment: a case-study example on indoor housing ventilation.
abstract: Quantitative health impact assessment (HIA) is increasingly being used to assess the health impacts attributable to an environmental policy or intervention. As a consequence, there is a need to assess uncertainties in the assessments because of the uncertainty in the HIA models. In this paper, a framework is developed to quantify the uncertainty in the health impacts of environmental interventions and is applied to evaluate the impacts of poor housing ventilation. The paper describes the development of the framework through three steps: (i) selecting the relevant exposure metric and quantifying the evidence of potential health effects of the exposure; (ii) estimating the size of the population affected by the exposure and selecting the associated outcome measure; (iii) quantifying the health impact and its uncertainty. The framework introduces a novel application for the propagation of uncertainty in HIA, based on fuzzy set theory. Fuzzy sets are used to propagate parametric uncertainty in a non-probabilistic space and are applied to calculate the uncertainty in the morbidity burdens associated with three indoor ventilation exposure scenarios: poor, fair and adequate. The case-study example demonstrates how the framework can be used in practice, to quantify the uncertainty in health impact assessment where there is insufficient information to carry out a probabilistic uncertainty analysis.
authors.affiliation: Department of Social and Environmental Health Research, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, 15-17 Tavistock Place, London, WC1H 9SH, UK. Electronic address: marco.mesa-frias@lshtm.ac.uk.
authors.forename: Marco
authors.initials: M
authors.lastname: Mesa-Frias
authors.forename: Zaid
authors.initials: Z
authors.lastname: Chalabi
authors.forename: Anna M
authors.initials: AM
authors.lastname: Foss
mesh_terms: D062489:Health Impact Assessment / Q000592:standards*; D006798:Housing / Q000592:standards*; D006801:Humans; D008962:Models, Theoretical; D035501:Uncertainty
keywords: Environmental health; Health impact assessment; Housing; Modelling; Uncertainty