Derivation of rate D of deaths per time after intervention. This sketch illustrates the derivation of the evolution of the rate D of deaths per time after a step decrease of pollution. D is proportional to the density of boxes, each box representing the deaths per small time step δt. After exposure reduction the deaths are delayed and the boxes shifted to the right. The dashed boxes show from where the boxes are shifted by the intervention. ΔL(t) = LE gain at time t after intervention.