Who reviews pages, when they are updated, and what the dates mean

Every page on this site shows three dates. The published date is the day the page first went live. The last-updated date is the day its content last changed in a way that matters. The next-review date is the day we last checked the page’s records, plus the review period for that kind of page. All three come from the page’s own data, never from the day the site was built.

The modified date changes only when the content materially changes

A spelling fix or a layout change does not move the last-updated date. The date moves when a fact, a figure, a source or a rule on the page changes. When that happens, the page records what changed. The dates you see are the same dates in the page’s structured data. A search engine or a citation tool reads the same published and modified values a person does.

If a page carries radon figures, the source sits under the first number, with the survey’s full citation and edition. For a government source, the source line names the department, the page title, the government’s own date modified and the original link. That lets you tell a page we refreshed from a source that changed under it.

See how every number on this site is labelled and dated.

A new source, a guideline change or a reader report triggers a review

Any of these changes starts a review ahead of schedule:

• A new edition of the Cross-Canada Radon Survey
• A change to the Canadian Radon Guideline, or to Health Canada testing or mitigation guidance
• A revised Canadian standard, including the CGSB 149 series
• A federal, provincial, territorial or municipal code change
• A change to a public radon program or grant
• A device recall or a change to the C-NRPP listings, on pages naming devices
• New evidence that changes how a claim should be read

One example: Health Canada updated its home measurement guidance on 22 May 2026. It replaced older instructions, including any limiting testing to winter. That is the kind of change that moves every page on how to test.

A reader report that shows an error is a trigger too. It goes through the corrections process.

See which source backs which claim. Report an error you found. Read the current testing rule.

Dates are never bumped to make a page look new

A check that changes nothing moves the next-review date and leaves the last-updated date alone. Each kind of page has a review period. We check a page at least that often, and sooner after any trigger listed above. The next-review date is that period added to the day the page’s records were last checked.

• Credentials and registry pages: monthly
• Grant and device pages: every 3 months
• Health, testing and building code pages: every 6 months
• General information pages: once a year
• Regional and municipal pages: on each survey release
• Report editions: frozen; a new edition is a new page

A page is published only when its content and the records it reads are complete. Until then it is not on the live site. The list above is the schedule.

Pages carry the Index’s name, not a person’s

The Index publishes under its own name. Pages carry no personal bylines, and no one has an author or reviewer page. Individual radon professionals do not get pages either; they appear on their company’s page.

Every page is checked against ten rules:

• Never turn a regional statistic into a personal risk assessment
• Never call a product approved by Health Canada unless Health Canada says so
• Never call a contractor the best
• Never imply a listing is an endorsement
• Never use a vendor as the sole source for a health claim
• Always name the edition of the survey
• Always use the current Health Canada testing guidance
• Always separate Canada’s 200 Bq/m³ guideline from the WHO’s 100 Bq/m³ reference level
• Identify uncertainty where evidence is limited
• Do not exaggerate

Every claim follows one order: “Claim, then source, then publication or edition, then date, then evidence.”