Every figure in Radon411's radon data comes from an official public agency, and the data sources page lists each one with its coverage and the date it was last checked. We do not take figures from readers, and we do not change a figure on request.
When a figure changes
Figures change when the agency behind them publishes an update, and the page then follows the new publication.
If a figure looks different elsewhere
Compare it with the agency's own publication. The figure here follows that publication, so the publishing agency is the place to raise a question about the figure itself. What each kind of number means is on the methodology page.
Professional listings
Licenses in the directory come from the issuing body's own records, and change when those records do. A business's name, address, phone and licenses are copied from the state's public license list, so the state's licensing program is the place to change them at the source; the directory follows its next list.
A business can also ask for its own listing to be corrected or removed, from the “Something wrong with this listing?” link on its profile. The request counts only once the business confirms it with a code emailed to its published address on record, or to an address at its own website's domain. A person then reviews it; no listing changes or disappears automatically.