Overview
- The Minnesota Pollution Control Agency issued an air quality alert covering noon to 9 p.m. Friday for the Twin Cities because ozone is expected to push the Air Quality Index into the orange range.
- Officials say the spike is caused by ground‑level ozone formed when volatile organic compounds and nitrogen oxides from vehicles and industry react in strong sunlight during hot, low‑humidity conditions.
- This alert is not related to wildfire smoke, and health officials warn that masks do not filter ozone because it is a gas rather than fine particles.
- The MPCA advised people with asthma, COPD or other lung or heart conditions to limit outdoor exertion and recommended reducing driving, avoiding mid‑day refueling and postponing gasoline‑powered lawn equipment.
- State forecasters warned on May 7 that a strong El Niño and drier, warmer weather raise the season’s risk of both more ozone episodes and future smoke days, which could lead to additional alerts this summer.