Read the whole report
Check units, device type, test duration, exact location, dates, building conditions, possible interference, laboratory or device information, and who conducted the measurement.
Why results vary
Weather, season, ventilation, HVAC operation, foundation conditions, occupancy patterns, and test duration can affect observed concentration. One short-term result may not represent the year-round average.
Choose the next step
For professional interpretation, use an appropriately Iowa-certified measurement professional. If valid evidence supports mitigation, use an Iowa-credentialed mitigation specialist. Medical questions belong with a healthcare professional.
Common questions
Does 3.9 pCi/L mean no action is needed?
No. EPA says levels below 4 pCi/L still pose risk and recommends considering reduction between 2 and 4 pCi/L.
Does 4 pCi/L diagnose exposure or illness?
No. It is an action level for a measured building concentration, not a personal dose or medical diagnosis.
Primary sources
Claims checked August 2, 2026. Guidance can change; confirm the current source before acting.