Corrections

Ours. A figure attached to the wrong county, a unit mislabelled, a ranking that sorts the wrong way, a caveat missing from a table. These are bugs in our pipeline or our writing, and we fix them and date the fix.

The source’s. Agencies revise. The NCI restates rates as registries mature, the EPA reissues air quality summaries when a monitor is recertified, and the CDC changes which states its model covers. When the underlying release changes, the next data build picks the change up and the build date on every page moves with it. We do not silently keep a superseded figure because it made a better headline.

• Fill a gap with an estimate of our own. If a source suppresses or omits a value, the page shows a dash. It will never show a state average standing in for a missing county.
• Quietly change a figure that a reader may have acted on. Substantive corrections are dated.
• Remove an unflattering number about a county because someone asked. The figure belongs to the agency that published it, not to us and not to the county.

Email admin@lung.com with the page, the figure, and what you think it should be. If you have the source release to hand, include it and we will be much faster.

We will check it against the release, tell you which of the two kinds of error it was, and fix it. If it turns out the figure is right, we will show you where it comes from rather than just asserting it.

Every page on this site is built from the same dated snapshot of the federal sources. The current build is 2026-08-21, and it is printed in the footer of every page so you always know the vintage of what you are reading. Sources, their periods and their limits are on the methodology page.