Company
About Radon411
Know the radon situation where you live.
Radon411 exists to answer one question well: what is the radon situation where a specific person lives, and what should they do about it. The location report, built from official government and scientific data, is the center of the site. The maps, guides, product comparisons and professional directory help a reader understand that answer and act on it.
How we handle data
We never make up a number. Every figure in Radon411's radon data comes from a named public agency, and a product's specifications are its maker's own, attributed to the maker. The methodology page explains what each kind of figure means. Where a figure is not available for a place, the page says so plainly rather than showing a guess or a silent zero. The data sources page names every agency we use and when each was last checked.
Editorial content
Explanatory and educational content on Radon411, including the questions, guides and level explainers under /resources/ and /radon-levels/, is written and maintained by the Radon411 Editorial Team. We do not publish content under an invented named expert or a fabricated "medically reviewed by" credit. Where a page would benefit from a licensed professional's review and that review has not yet happened, we say review is pending rather than imply it occurred. What we do claim is narrower and true: content is checked for factual accuracy against EPA, CDC, WHO and USGS source material, and every page states the date it was last updated.
How we handle mistakes
Every figure, citation and piece of guidance on Radon411 follows the official publication behind it, and figures change when the publishing agency issues an update. The corrections page sets this out. We do not quietly delete a page instead of fixing it, and we do not leave a known error live because it is inconvenient to change.
Commercial policy
Featured listings in the professionals directory are paid placements, labelled Featured where they appear. Product links go to Amazon and are affiliate links; the affiliate disclosure explains them.
How we research
Check your area
Open the free page for a county or state: its predicted potential and any reported testing data.
Imagery
Photographs and illustrations
Radon411 uses a photograph only where it shows exactly what the sentence beside it describes, and uses drawings everywhere else. The four photographs on the site are archive pictures of a material, a house and radon work. None shows a home, a test or a system that Radon411 was involved in. Each is in the public domain or dedicated to it (CC0, the Public Domain Mark, or a work of the U.S. federal government), so none needs a credit, and each is credited anyway.
The drawings of people, houses, tools and radon systems are original to Radon411. They are illustrations, not portraits of anyone. The state outlines are drawn from Census Bureau cartographic boundary files.
- A technician in a high-visibility vest holds a card reading "Do not disturb, radon test in progress" under a pair of radon detectors on a wall. U.S. Navy photo by Petty Officer 1st Class Sean P Rinner, Wikimedia Commons, public domain.
- A sump pump standing on a covered pit in the corner of a concrete floor, in black and white. United States Department of Energy, Wikimedia Commons, public domain.
- A small shingled house standing on a concrete foundation, with bare ground around it. YellowstoneNPS, Flickr, public domain.
- A close view of coarse-grained granite split by a deep crack. Kent G. Budge, Wikimedia Commons, CC0.
