We will estimate the health benefits associated with the reduction of exposure to particulate air pollution (PAP) from WP2 practices. HIA is the application of existing, validated, concentration-response functions (CRFs) to background rates of morbidity to assess the impact on population health of specified changes in exposure. Using this HIA methodology, we will assess by how much, if at all, the burden of disease would be reduced if identified exposure reduction measures were implemented at national scales.

HIA will be conducted for a range of scenarios, assuming varying levels of success of the specific practices. Impact on health will be calculated by application of CRFs to background rates of disease, population and changes in PAP concentrations attributed to the selected interventions. For mortality impacts, we will start with core PM-health relationships as reviewed by WHO, and the work of Global Burden of Disease (GBD). We will consider more recent evidence on attribution of particles and, if indicated, the shape of the CRFs at relatively high concentrations (compared to those in North America and Europe where the main cohort studies were carried out) and CRFs for implementation will be decided.

For morbidity, we will start from the core set of PM-disease combinations that, following review of HIAs by WHO, US EPA, GBD and others, were proposed for application in LMICs and more widely, i.e. respiratory and cardiovascular hospital admissions; Restricted Activity Days (RADs); acute bronchitis in children aged 6-12 or 6-18 years; and acute lower respiratory illness (ALRI) in children aged <5 years. We will review the appropriateness of these for use in Indonesia and Nepal, and augment them with assessments of uncertainty in the parameters to derive CRFs that are relevant to these populations. Implementation of the CRFs will depend intrinsically on the availability of background rates of the selected health outcomes in children in Indonesia and Nepal. Mortality and morbidity rates will be accessed from national sources or wider statistics (e.g. mortality: World Health Organization; morbidity: the GBD results tool). Where suitable data cannot be sourced from the relevant countries, we will investigate the applicability of using available data from similar countries.