When the Environmental Protection Agency unveiled a proposal this week to give states more latitude in regulating pollution from power plants within their borders, it came with a sobering forecast of its likely impact on Americans’ health.

By 2030, adoption of the Affordable Clean Energy Rule could lead to 470 to 1,400 additional premature deaths each year because of an increase in tiny airborne particles. Children with asthma could wind up missing 21,000 extra days of school annually, and up to 48,000 more people could experience “exacerbated asthma” as air quality deteriorates.