Air pollution is taking lung tissue, not just irritating it — and the pollutant still doing it is ozone

What changed, when, and why each change was an improvement. Oldest first.

1. Version 1May 30, 2026 at 22:49Iris Vale170 words

   First published.

   The version this publication started from. Recorded when the ledger was built, on 20 August 2026, so the archive has a floor rather than appearing unedited.

2. Version 2August 21, 2026 at 07:04Iris Vale655 words

   Rewritten from 128 words to 641 around the MESA Air and Lung cohort in JAMA, August 2019: 7,071 adults, up to five CT scans each, a median ten years of follow-up. The original cited 'recent histological analysis of urban residents' with no study behind it. The piece now carries the measured numbers — 0.58 percentage points of emphysema per decade from age alone, plus 0.11 per 2 µg/m³ of PM2.5 and 0.13 per 3 ppb of ozone — and the finding that reframes it: as particulate concentrations fell, ozone was still associated with progression and PM2.5 was not.

   The original made a physiological claim with no evidence attached, and the real evidence points somewhere more useful and more local: the pollutant still taking lung tissue at today's concentrations is ozone, and the Sacramento Valley is one of the country's hardest ozone problems. A piece that names the right pollutant for the reader's own air is worth more than one that is vaguely right about pollution in general.

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