INDIANAPOLIS — Concerns about elevated particulate matter in the air is prompting a Knozone Action Day in Indianapolis.

The Indianapolis Office of Sustainability said the declaration comes as the Indiana Department of Environmental Management notes smoke is lingering in the area of Marion, Boone, Hendricks, and Hamilton Counties. High particulate matter values have been monitored on Indy’s west side.

The particulate matter is coming from the Walmart distribution center in Plainfield. A plume of black smoke was sent into the air, which was visible for miles. The fire also dumped debris and ashes on surrounding areas.

This is the first Knozone Action Day for 2022. They are issued when ozone or fine particulate matter (PM2.5) levels rise above certain thresholds.

During these days, the air quality may become unhealthy for sensitive individuals, especially active children, the elderly, and anyone suffering from lung disease or other serious health problems.

The Office of Sustainability says air pollutants like ozone and particulate matter pose a public health and environmental justice issue as they can cause increased hospitalizations, asthma, bronchitis, heart attacks, chronic obstructive pulmonary disease (COPD), and premature death, according to the American Public Health Association. 10.9% of Indianapolis residents live with asthma, and 8.6% of Indianapolis residents live with COPD; both these figures are higher than the national average.

IDEM encourages everyone to help reduce fine particles in the air by making changes to daily habits. You can:

  • Avoid burning wood in fireplaces or wood-fired boilers and any other unnecessary fires.
  • Reminder: Indiana’s open burning laws make it illegal to burn trash and generally prohibit open burning. Visit for more information.
  • Reduce activity time outdoors to reduce unhealthy exposure to fine particulate matter.
  • Combine errands into one trip.
  • Avoid using gasoline-powered equipment or gas-powered recreational vehicles.
  • Keep your engine tuned, and don’t let your engine idle (e.g., at a bank or restaurant drive-thru).
  • Conserve energy by turning off lights or setting the thermostat to 70 degrees or lower.