For 4000 lives saved, and at a valuation of roughly $7 to $9 Million/life (US) to be consistent with US gov’t engineering practices and regulations, perhaps $30 to $40 billion to be consistent with other US policy initiatives.
If you even spend, say, $100 Billion on this environmental concern (implicitly valuing $25M/life), you will underinvest in other governmental activities (e.g. DOT) that valued life at $9M/life, so reprogramming funds from air pollution to DOT would be estimated to save more lives. At first SWAG (linearity/hand-waving) implicitly accepting an additional 6000 lives lost due to such a misinvestment.
Cf. https://en.wikipedia.org/wiki/Value_of_life#United_States
If you even spend, say, $100 Billion on this environmental concern (implicitly valuing $25M/life), you will underinvest in other governmental activities (e.g. DOT) that valued life at $9M/life, so reprogramming funds from air pollution to DOT would be estimated to save more lives. At first SWAG (linearity/hand-waving) implicitly accepting an additional 6000 lives lost due to such a misinvestment.