Yes. Children breathe more rapidly and have developing lungs, making them more vulnerable to radon-induced cellular damage. The EPA emphasizes mitigation for homes with children, particularly where they sleep on lower floors.
More detail
Children have roughly 2x the breathing rate of adults per kilogram of body weight, and their lung tissue is in active cellular division throughout childhood. Both factors increase the dose-rate of radon-daughter alpha radiation per unit of indoor exposure. Long-term exposure during childhood appears to carry higher per-unit-exposure cancer risk than equivalent adult exposure, though epidemiological data is harder to isolate. Practical implication for Cincinnati households: if a child sleeps in a basement bedroom or in a finished lower-level family room with extended hours of use, the household-weighted exposure picture is meaningfully worse than for an upper-floor-only sleeping configuration. Mitigation cost-benefit math tilts strongly toward "mitigate" at the borderline 2.0-4.0 pCi/L range when children are present. Cincinnati school context: Ohio's radon law does not set a school testing schedule, but EPA recommends that all schools be tested and the Ohio Department of Health recommends retesting school buildings every five years or after significant renovation. Parents concerned about exposure during school hours can ask the school for its most recent radon test result. Home is typically the higher-exposure environment.