“…A spatial ecological design can be used to estimate the impacts of air pollution on health by comparing geographical contrasts in air pollution and infection risk across contiguous small areas ( Huang et al, 2018 , Napier et al, 2018 , Rushworth et al, 2014 ). In such studies, the outcome data are counts of disease cases occurring in each areal unit while the pollution concentrations in each areal unit are typically estimated by applying Kriging (see Diggle and Ribeiro, 2007 ), to data from a sparse monitoring network, or by computing averages over modelled concentrations (grid level) from an atmospheric dispersion model ( Wu et al, 2020 , Maheswaran et al, 2006 , Lee et al, 2009 , Warren et al, 2012 ), or by combining both to obtain a better prediction ( Huang et al, 2018 , Vinikoor-Imler et al, 2014 , Sacks et al, 2014 ).…”