Don't discount the impact of reduction of air pollution on all causes of mortality. It's not often discussed, but every so often someone makes the connection between small particulates and heart attacks, etc.
Short-term exposure can increase the risk of heart attack, stroke, arrhythmias and heart failure in susceptible people, such as the elderly or those with pre-existing medical conditions, according to the statement."
https://www.heart.org/en/health-topics/consumer-healthcare/w...
Risks are generally thought to be immediate, but very low.