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 research
Check your area
Open the report for a county or state: its predicted potential and any reported testing data.
How we handle data
We never make up a number. Every figure on Radon411 comes from a named public agency, and 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 We do not publish content under an invented named expert or a fabricated "medically reviewed by" credit.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
If a figure, a citation or a piece of guidance on Radon411 is wrong, out of date, or does not match its source, tell us with the form on the corrections page. A correction is checked against the original source and, where confirmed, the page is updated and its "last updated" date changes to reflect it. 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. The same page says what to include and how a directory listing is corrected.
Commercial policy
Radon411 does not run lead generation: no "get matched" forms, no selling of visitor contact information. Directory listings link straight to the business's own website or phone number. If paid listings are ever offered, a paid plan could change only how a listing is presented; it can never create or alter a certification or verification status, or change the order of the directory. Affiliate links, where they exist, are disclosed where they appear; the affiliate disclosure explains them.
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.