Primary evidence product · England 30-day official monitoring review
National coverage criteria met
What England's monitoring data showed
This Air Quality Project analysed 9,491 valid pollutant-day observations across 4,201 unique station-days from 142 reporting stations, covering 9 of 9 English regions between 2026-08-12 and 2026-09-10.
Descriptive pollutant findings
These are measured 30-day station and regional patterns. They are not source-attribution, exposure, health or legal-compliance findings.
Carlisle Morton A595 · North West · 30 valid days
Highest eligible regional median: North West (4.40 µg/m³).
WHO-context pollutant-day observations: 27
Maidstone Upper Stone Street · South East · 30 valid days
Highest eligible regional median: South East (9.75 µg/m³).
WHO-context pollutant-day observations: 2
Sheffield Barnsley Road · Yorkshire and the Humber · 28 valid days
Highest eligible regional median: London (14.35 µg/m³).
WHO-context pollutant-day observations: 160
Interpretation boundary: provisional official monitoring evidence; WHO guideline comparisons are contextual and are not UK legal exceedance counts.
ASSESSMENT UNAVAILABLE
No England-wide current environmental assessment is published because the governed monitoring coverage and freshness gate was not met.
The station-level PM2.5 operational screen is reported separately and cannot override the governed England-wide coverage/freshness gate.
Evidence acquisition: PASSED. 11 configured joins remain pending or blocked. The PM2.5 operational screen and England-wide current assessment are distinct from the 30-day England AURN review. Screening evidence only; no source attribution, legal or health finding.
Current publication status
Source-collection integrity
Passed
Confirms current-data acquisition, provenance and quality-stage mechanics only.
Live SOS source coverage
Coverage Gap
107 of 129 governed PM sites represented through SOS; 82.9% against a 85.0% live-source threshold.
This governs the live/current SOS route only; it is not the England 30-day AURN review completeness metric.
Scientific episode release
Operational screen complete
Adjusted PM2.5 candidate count: 0; eligible station assessments: 68; not eligible or not assessed: 59; required missing dimensions: none reported.
Acquisition status distinguishes primary monitoring evidence from mandatory contextual sources. A degraded context harvest may support a clearly labelled data-availability release, but not an environmental episode, source, compliance, exposure or health finding. No England-wide current environmental assessment is published because the governed monitoring coverage and freshness gate was not met. No episode was available for corroboration. Cross-source convergence was not applicable to an episode in this run.
A green harvest gate is not a pollution-source finding. Source attribution, causation, permit breach, exposure and health conclusions remain prohibited unless the separate scientific gate passes.
Evidence acquired and classified
What the platform successfully collected this run
14 source streams reached connectivity or a stronger stage. Each source remains separately labelled by evidence role and validation maturity.
Record counts belong to different evidence classes and are not added together as a single scientific total. Downloaded context is not automatically treated as validated environmental evidence.
Current observatory position
Evidence platform active; scientific release constrained
This Air Quality Project is operating in an England Phase 1 scope with a UK-ready architecture. Official measurements drive discovery, and each release is limited to the geography actually evidenced. The unproven legacy Google Drive archive is disabled and contributes no measurement, anomaly, corroboration or scientific finding. Every displayed number is generated from the latest validated workflow output and is withheld when its source stage is insufficient.
Latest generated UTC: 2026-09-11T12:53:25Z
Active and validated data streams
| Data stream | Validated stage | Records / series | Evidence role |
|---|---|---|---|
| Imperial College London LAQN API | Quality Validated | 769 | ground monitoring network |
| Defra UK-AIR Sensor Observation Service | Quality Validated | 237 | ground measurement |
| Environment Agency Public Register | Records Downloaded | 23,554 | regulatory record |
| Department for Transport Road Traffic Statistics API | Records Downloaded | 10,000 | official traffic baseline |
| Met Office Weather DataHub Land Observations | Records Downloaded | 576 | official meteorology |
| NASA FIRMS VIIRS and MODIS active fire data | Records Downloaded | 350 | satellite fire context |
| PurpleAir API | Records Downloaded | 287 | low cost sensor network |
| Met Office Weather DataHub Global Spot | Records Downloaded | 10 | official forecast meteorology |
| Copernicus Atmosphere Monitoring Service | Records Downloaded | 2 | atmospheric model |
| NASA Earthdata Common Metadata Repository | Metadata Only | 28 | satellite catalogue |
| OpenAQ v3 | Metadata Only | 0 | ground measurement aggregator |
| National Atmospheric Emissions Inventory | Metadata Only | 0 | emissions inventory |
| Defra UK-AIR Atom downloads | Metadata Only | 0 | official download catalogue |
| Copernicus Data Space STAC Sentinel-5P | Metadata Only | 0 | satellite catalogue |
Mandatory stream limitations
- planning_data: observed Not Applicable No Discovered Event; required Records Downloaded.
A listed limitation means the relevant stream has not yet reached the required validation stage. It is shown openly rather than replaced with stale data or a false success state.
Current data service
Live monitoring active across 124 fresh sites
175 of 237 time series were inside the freshness window and 0 preliminary screening observation(s) were selected for follow-up.
Context joins are reported by state, not as misleading zero findings
No current event bundle is fabricated when observations are stale. Linkage readiness is retained for the next evaluable event, while source contribution and causation remain outside automated output.
Episode evidence bundles
No preliminary screening event was available for an episode bundle in this run.
Unvalidated legacy material is excluded by design
The legacy Google Drive archive contributes no measurement, anomaly, corroboration or finding. Any historic record must be reacquired from its original publisher and independently validated before it can influence This Air Quality Project output.
Practical result: the current national review is based on newly acquired official monitoring evidence rather than inherited unverified material.
Scientific boundary
This status describes acquisition, validation and evidence-integration readiness. It is not source attribution, a permit-compliance finding, an exposure estimate, a health-risk assessment or a legal determination.
Scientific evidence and software assurance are different
Scientific evidence
Measurements, station and regional coverage, descriptive calculations, source records and stated limitations are the evidence available for review.
Engineering assurance
Automated checks confirm that the pipeline followed its declared rules. They do not constitute peer review, accreditation, regulatory approval or institutional endorsement.
Operational PM2.5 screening interpretation
Adjusted PM2.5 candidate count: 0; eligible station assessments: 68; not eligible or not assessed: 59. A count of zero means only that no eligible assessment crossed every current operational criterion. It does not establish absence of pollution, harmless concentrations, assessment of every station or screening of all pollutants.
Formal false-discovery-rate control has not been established. The live screen does not identify a source and is not a health assessment or regulatory determination.
Why the monitoring denominators differ
The observatory publishes separate products with separate eligibility gates. Their counts must not be treated as one denominator.
133current-screen identified sites
—30-day review stations with governed evidence
—AURN sites discovered by the review inventory
- Discovered sites are the discovery inventory before eligibility filters.
- 30-day review stations have governed evidence for the completed window.
- Current-screen sites belong to the separate operational PM2.5 screen.
Series terminology
Identified series are configured/discovered pollutant time series. Reporting series supplied accepted numeric observations. Fresh series/sites meet the governed freshness window.
235 / 237reporting / identified series
124current sites meeting freshness gate
Routine evidence convergence
237ordinary current observations eligible for routine convergence
2 / 2applicable routine joins executed
0routine joins fully validated
Routine convergence runs independently of anomaly detection. A day with zero screening candidates can still produce useful meteorology and monitor-role corroboration.
Sentinel-5P processing state
45recent catalogue items discovered
0 / 1bounded products processed
0QA-valid pixels retained across processed products
Satellite processing status: not configured product download credentials. Sentinel-5P Level-2 products are column/context evidence, not ground-level monitor concentrations. The processing receipt retains product-specific QA, product identifiers, hashes, numerical summaries and compact provenance imagery.
Traffic evidence: what is actually available
10,000 official DfT traffic recordsrecords downloaded
2025AADF evidence year
annual average daily flowtemporal resolution
The build acquired official DfT AADF records for 2025, providing annual traffic and vehicle-class baseline context.
Boundary. Annual AADF evidence is not contemporaneous event traffic. Event-specific traffic still requires time-aligned observations such as WebTRIS or equivalent official data before traffic can support an episode-level competing-source assessment.
Operational PM2.5 screen: threshold and multiplicity boundary
The current screen uses operational screening parameters including a 24-hour PM2.5 mean floor of 15 µg/m³ and a robust station-history score of 3 or greater. These are project screening parameters, not UK legal limits, WHO guideline values, health thresholds, or evidence of a pollution source.
Calibration status. Until an empirical null, sensitivity analysis and dependence-aware calibration are published, the project does not claim that the nominal Benjamini–Hochberg alpha establishes a validated false-discovery rate. The scores are screening statistics rather than calibrated p-values.
WHO context is not UK legal compliance
For NO₂, the WHO 2021 annual air-quality guideline is 10 µg/m³, while the UK statutory annual-mean limit value/objective is 40 µg/m³. WHO-context pollutant-day counts must not be interpreted as UK legal exceedance counts.