Air quality in Cornwall: the AQMAs, the monitoring and the 2026–2031 action plan

Cornwall's statutory air quality position has changed more in the last two years than in the previous ten. Six Air Quality Management Areas have been revoked since November 2024. Three remain. A new action plan has been drafted but, as far as the public record shows, not yet adopted.

This page sets out what is currently declared, on what evidence, and where the published data lives. Everything below is sourced to Cornwall Council or Defra. It reflects the position as at 12 August 2026.

What an AQMA is, briefly

Under Part IV of the Environment Act 1995, as amended by the Environment Act 2021, a local authority must review air quality in its area and declare an Air Quality Management Area wherever an air quality objective is being, or is likely to be, exceeded. Declaration triggers a duty to produce an Air Quality Action Plan. When monitoring shows sustained compliance — in practice five consecutive years, in line with Defra's LAQM.TG22 guidance — the authority consults Defra and may revoke.

The objectives that matter in Cornwall are both for nitrogen dioxide: an annual mean of 40 µg/m³, and a 1-hour mean of 200 µg/m³ not to be exceeded more than 18 times a year (2025 ASR, Appendix E).

The three AQMAs currently declared

Every AQMA in Cornwall is, and has always been, a road-traffic NO₂ designation. None relates to particulate matter or to industry.

Source: Defra UK-AIR AQMA register for Cornwall Council and the draft AQAP, Table 2-1.

Two of the three are still in exceedance. In 2024, worst-case relevant exposure was 42.3 µg/m³ at TDF6 in Tideford and 41.3 µg/m³ in Launceston, against the 40 µg/m³ objective. Gunnislake has been compliant for two consecutive years; the council intends to keep the designation until three years of robust compliance.

Tideford is the only Cornish AQMA on a National Highways road. The A38 through the village carried an annual average daily flow of 21,938 vehicles (DfT, 2024) with a significant heavy-goods share, past houses with no setback from the carriageway. The draft plan calculates the reductions in road NOₓ needed to reach compliance: 8% at TDF6, 5% at LAN5 in Launceston.

The six AQMAs revoked

Revocation dates as recorded on the Defra register. Each revocation followed a Defra-reviewed evidence report; all six reports are published on the council's AQMA page.

Revocation does not end monitoring. Cornwall Council designates these six as Air Quality Areas of Concern and continues diffusion tube monitoring in each, with Priority 5 of the draft action plan committed to maintaining compliance there.

How Cornwall monitors

In 2024 the council ran passive NO₂ diffusion tube monitoring at 117 sites, and continuous monitoring at three, all in Truro: TRU8M (Treliske) and TRU18M (Tregolls), both measuring NO₂ by chemiluminescence and PM10 by light scattering, and TRU29M (Highertown), PM10 only. Tubes were supplied by Somerset Scientific Services to August 2024 and Gradko International from September, both UKAS-accredited and participating in the AIR proficiency testing scheme.

Separately, Defra's national network operates one automatic station in Cornwall: Saltash Callington Road, an AURN urban traffic site measuring PM10 and PM2.5 hourly since 2013. It is not a council site, and there is no AURN NO₂ station in the county.

Three points matter when reading the published numbers. Tube results are bias-adjusted, annualised where data capture falls below 75%, and distance-corrected where the tube is not at a point of relevant exposure. Three Truro sites exceeded 40 µg/m³ in 2024 but fall below 30 µg/m³ once corrected to the nearest façade — which is why Truro's AQMA was still revocable.

The action plan: draft, not adopted

The plan currently linked from the council's air quality pages is the Cornwall Air Quality Action Plan of November 2020, published alongside the Clean Air for Cornwall Strategy in December 2020. The draft says that plan ran to November 2025.

Its replacement, the draft Air Quality Action Plan 2026–2031, is dated 28 November 2025. Consultation opened on 2 December 2025 and the survey closed on 30 January 2026 (Let's Talk Cornwall; the council's news item states 31 January). The document is explicit about its own status: it "is a draft version and will be adopted from (to be confirmed)", and its consultation chapter is still a template marked to be completed.

As at 12 August 2026 there is no published record that the 2026–2031 plan has been adopted, and the council's air quality pages still present the 2020 plan. Treat it as a draft until the council says otherwise.

Its five stated priorities are: reduce transport emissions in and beyond the AQMAs; support behaviour change through schools and employers; strengthen monitoring and public access to data, including online dashboards; embed air quality in planning and infrastructure decisions; and maintain compliance in the Air Quality Areas of Concern.

Where the published data lives

• Annual Status Reports 2017–2025 — cornwall.gov.uk air quality. The 2025 ASR (June 2025, covering calendar year 2024) is the most recent published; it carries every tube location, monthly result and QA/QC calculation in its appendices.
• AQMA boundaries, declaration and revocation dates — Defra UK-AIR, the authoritative register.
• Interactive monitoring map — the council's ArcGIS viewer.
• Revocation reports — on the AQMA page.
• The Environmental Protection team can be reached at cep@cornwall.gov.uk.

Why we wrote this

Make Sense is based in Falmouth. Cornwall is our own county, and the statutory picture here is genuinely hard to read across three websites, so we assembled it in one place.

We are building a multi-sensor pod that mounts to vehicles already making their rounds, so that ordinary journeys can survey air quality, road surface condition and building heat loss. The first vehicle system is in build. We are not monitoring anything in Cornwall today, we have no relationship with Cornwall Council, and nothing on this page is endorsed by them. Reference-grade and diffusion tube networks remain the statutory evidence base; mobile sensing is a different instrument for a different question — spatial coverage between fixed points.

If you work on air quality in Cornwall, in a council, a parish, a network or a university, and you would find it useful to compare notes, we would be glad to hear from you. Get in touch.

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Sources

• Cornwall Council, Air Quality Management Areas — https://www.cornwall.gov.uk/environment/environmental-protection/air-quality/air-quality-management-areas/
• Cornwall Council, Air quality (ASRs, map, strategy) — https://www.cornwall.gov.uk/environment/environmental-protection/air-quality/
• Cornwall Council, 2025 Air Quality Annual Status Report (June 2025) — https://www.cornwall.gov.uk/media/4jmcqwva/cornwall-council-asr-2025.pdf
• Cornwall Council, Cornwall Air Quality Action Plan (November 2020) — https://www.cornwall.gov.uk/media/s13lt3sr/cornwall-action-plan-04-11-2020.pdf
• Cornwall Council, Draft Air Quality Action Plan 2026–2031 (28 November 2025) — https://letstalk.cornwall.gov.uk/air-quality
• Cornwall Council news, "Have your say on Cornwall Council's plan to improve air quality" (2 December 2025) — https://www.cornwall.gov.uk/council-news/environment-culture-and-planning/have-your-say-on-cornwall-council-s-plan-to-improve-air-quality/
• Cornwall Council, Clean Air for Cornwall Strategy (2020) — https://www.cornwall.gov.uk/media/4mzjd4l5/clean-air-for-cornwall-strategy-web.pdf
• Defra UK-AIR, AQMA register for Cornwall Council — https://uk-air.defra.gov.uk/aqma/local-authorities?la_id=447
• Defra UK-AIR, Saltash Callington Road site information (UKA00569) — https://uk-air.defra.gov.uk/networks/site-info?uka_id=UKA00569
• Environment Act 1995, Part IV — https://www.legislation.gov.uk/ukpga/1995/25/part/IV