MI SB0490

Requires the department to forecast air quality index (AQI) at least 24 hours in advance and publicize forecasts on its website and through other means using accurate meteorological and topographical procedures.

Mandates the department declare "action days" for geographic areas when moderate or worse air quality is expected, with special designation of "winter thermal inversion action days" for November through March conditions.

Directs the department to review its AQI reporting and forecasting program within 180 days and potentially revise ozone or PM 2.5 standards, pollution prevention measures, and industry emissions restrictions when thermal inversions are forecast.

Requires the department director to convene a workgroup including public health experts, air quality experts, environmental organizations, and residents from high-pollution areas to study thermal inversions and recommend state actions to improve air quality and protect public health.

Takes effect 90 days after enactment into law.