Scientific evidence
Measurements, station and regional coverage, descriptive calculations, source records and stated limitations are the evidence available for review.
Current assessment status: station screen evaluated england assessment withheld
The station-level screen was evaluable, but the England-wide assessment remains withheld because the governed national coverage gate was not met.
This status describes what the current evidence can support. It is not a clean-air, safety, compliance or source-attribution finding.
Known source universe54Actual and potential sources retained
Operational sources9Record-bearing, not automatically validated
Monitoring sites133Within the evidenced geography
Fresh sites12896.2% coverage
Executed joins00 validated
Evidence gaps6Required dimensions below quality-validated
What this review can establish
- Which sources were registered, accessed and technically validated.
- The evidenced geography, time window, freshness and missingness.
- Which record joins were attempted, executed and validated.
- Which evidence dimensions and provenance fields remain incomplete.
- Reproducible screening patterns that require further corroboration.
What this review does not establish
- which source caused an observed concentration
- whether any operator breached a permit or law
- whether air was safe or dangerous
- whether a health effect occurred
- whether a location complied with a regulatory objective
- whether a zero-candidate result was incorrectly interpreted as absence of pollution
Evidence basis
- Evidenced geography
- England
- Monitoring time series
- 237
- Availability stages
- {'actual_operational': 9, 'actual_partial': 12, 'disabled': 1, 'potential_registered': 32}
Counts from heterogeneous sources describe records, products or catalogue entries. They must not be compared as pollutant magnitude or treated as equivalent evidence.
Evidence-dimension readiness
Quality validation, operational access and registered potential are kept separate. Independent verification is only possible where distinct authority families and compatible evidence are available.
| Dimension | Status | Best available sources | Independent families possible |
|---|---|---|---|
| ground measurement quality | quality validated | uk_air_sos_current_particle, laqn_imperial | Yes |
| comparator and background | quality validated | uk_air_sos_current_particle, laqn_imperial | Yes |
| official meteorology | operational validation pending | met_office_land_observations, met_office_global_spot | Yes |
| traffic activity | operational validation pending | dft_road_traffic | No |
| regional model context | operational validation pending | cams | No |
| fire and satellite context | operational validation pending | nasa_firms | Yes |
| regulatory and operational context | operational validation pending | environment_agency_public_register | Yes |
| competing source assessment | operational validation pending | environment_agency_public_register, dft_road_traffic, met_office_land_observations, met_office_global_spot, cams, nasa_firms | Yes |
| uncertainty and missingness | quality validated | uk_air_sos_current_particle, laqn_imperial | Yes |
| complete provenance | quality validated | uk_air_sos_current_particle, laqn_imperial | Yes |
Cross-reference execution
Input readiness is not execution. Execution is not scientific validation. A validated technical join is still not evidence of contribution or causation.
| Join | Status | Executed | Validated | Source stages |
|---|---|---|---|---|
| facility operator | candidate inputs available | No | No | environment_agency_public_register: records_downloaded, companies_house: credential_present |
| facility permit | candidate inputs available | No | No | environment_agency_public_register: records_downloaded, sepa_public_register: not_configured, nrw_public_register: not_configured, niea_records: not_configured |
| monitor facility spatial | candidate inputs available | No | No | uk_air_sos_current_particle: quality_validated, uk_air_atom: metadata_only, laqn_imperial: quality_validated, openaq: metadata_only, waqi: not_applicable_no_discovered_event, purpleair: records_downloaded |
| observation meteorology temporal | candidate inputs available | No | No | met_office_land_observations: records_downloaded, openweather: not_applicable_no_discovered_event, cams: records_downloaded |
| observation traffic | candidate inputs available | No | No | dft_road_traffic: records_downloaded, national_highways_webtris: not_configured |
| observation fire | candidate inputs available | No | No | nasa_firms: records_downloaded, nasa_earthdata_cmr: metadata_only, cdse_sentinel5p: metadata_only |
| observation regional background | candidate inputs available | No | No | uk_air_sos_current_particle: quality_validated, uk_air_atom: metadata_only, laqn_imperial: quality_validated, openaq: metadata_only, eea_air_quality: not_configured, emep_ebas: not_configured, cams: records_downloaded |
| facility emissions | candidate inputs available | No | No | naei: metadata_only, uk_prtr: not_configured, environment_agency_public_register: records_downloaded, waste_data_interrogator: not_configured |
| facility planning | blocked missing inputs | No | No | planning_data: not_applicable_no_discovered_event, local_planning_portals: not_configured |
| receptor population | blocked missing inputs | No | No | ons_geography: not_configured, ons_census_api: not_configured, nomis: credential_present, imd: not_configured, get_information_about_schools: not_configured, cqc_care_directory: not_configured, natural_england_designated_sites: not_configured |
| aggregate health context | blocked missing inputs | No | No | ohid_fingertips: not_configured |
Source universe and maturity
The complete known source universe remains visible, including unavailable, unimplemented and provenance-incomplete sources.
Open the full source register (54 sources)
| Source | Authority | Jurisdiction | Stage | Availability | Records | Capabilities | Provenance |
|---|---|---|---|---|---|---|---|
| Defra UK-AIR Sensor Observation Serviceuk_air_sos_current_particle | official | unrecorded | quality validated | actual operational | 237 | comparator and background, complete provenance, ground measurement quality, uncertainty and missingness | Complete |
| Defra UK-AIR Atom downloadsuk_air_atom | official | UK | metadata only | actual partial | 0 | Not mapped | Complete |
| Imperial College London LAQN APIlaqn_imperial | official_network | London_and_south_east | quality validated | actual operational | 654 | comparator and background, complete provenance, ground measurement quality, uncertainty and missingness | Complete |
| Environment Agency Public Registerenvironment_agency_public_register | official | England | records downloaded | actual operational | 23,559 | competing source assessment, regulatory and operational context | Complete |
| Planning Data APIplanning_data | official | England | not applicable no discovered event | potential registered | 0 | competing source assessment, receptor population context, regulatory and operational context | Complete |
| National Atmospheric Emissions Inventorynaei | official | unrecorded | metadata only | actual partial | 0 | competing source assessment, regulatory and operational context | Gaps recorded |
| Department for Transport Road Traffic Statistics APIdft_road_traffic | official | Great_Britain | records downloaded | actual operational | 10,000 | competing source assessment, traffic activity | Complete |
| OpenAQ v3openaq | provider_attributed | global | metadata only | actual partial | 0 | comparator and background, complete provenance, ground measurement quality, uncertainty and missingness | Complete |
| World Air Quality Index APIwaqi | provider_attributed | unrecorded | not applicable no discovered event | potential registered | 0 | comparator and background, complete provenance, ground measurement quality, uncertainty and missingness | Gaps recorded |
| OpenWeather current conditionsopenweather | commercial_provider | unrecorded | not applicable no discovered event | potential registered | 0 | competing source assessment, official meteorology | Gaps recorded |
| Met Office Weather DataHub Land Observationsmet_office_land_observations | official | UK | records downloaded | actual operational | 576 | competing source assessment, official meteorology, receptor population context | Complete |
| Met Office Weather DataHub Global Spotmet_office_global_spot | official | unrecorded | records downloaded | actual operational | 10 | competing source assessment, official meteorology | Gaps recorded |
| Copernicus Atmosphere Monitoring Servicecams | official_model | europe_global | records downloaded | actual operational | 2 | competing source assessment, regional model context | Complete |
| Copernicus Data Space STAC Sentinel-5Pcdse_sentinel5p | official | global | metadata only | actual partial | 0 | competing source assessment, fire and satellite context | Complete |
| NASA Earthdata Common Metadata Repositorynasa_earthdata_cmr | official | unrecorded | metadata only | actual partial | 27 | competing source assessment, fire and satellite context | Gaps recorded |
| PurpleAir APIpurpleair | community_sensor | unrecorded | records downloaded | actual operational | 286 | comparator and background, complete provenance, ground measurement quality, uncertainty and missingness | Gaps recorded |
| NewsAPInewsapi | secondary_discovery | global | not applicable no discovered event | potential registered | 0 | document discovery | Complete |
| NewsData.ionewsdata | secondary_discovery | global | credential present | actual partial | 0 | document discovery | Complete |
| SerpAPIserpapi | secondary_discovery | global | credential present | actual partial | 0 | document discovery | Complete |
| Companies House APIcompanies_house | official | UK | credential present | actual partial | 0 | competing source assessment, regulatory and operational context | Complete |
| Google Drive legacy archivegoogle_drive | mixed_unverified | unrecorded | archive disabled | disabled | 0 | Not mapped | Gaps recorded |
| OpenAI APIopenai | derived_non_evidentiary | unrecorded | credential present | actual partial | 0 | Not mapped | Gaps recorded |
| Gemini APIgemini | derived_non_evidentiary | unrecorded | credential present | actual partial | 0 | Not mapped | Gaps recorded |
| UK-AIR Data Selectoruk_air_bulk_historical | official | UK | not configured | potential registered | 0 | Not mapped | Complete |
| SEPA Public Registersepa_public_register | official | Scotland | not configured | potential registered | 0 | competing source assessment, regulatory and operational context | Complete |
| Natural Resources Wales Public Registernrw_public_register | official | Wales | not configured | potential registered | 0 | competing source assessment, regulatory and operational context | Complete |
| Northern Ireland environmental regulation recordsniea_records | official | Northern Ireland | not configured | potential registered | 0 | competing source assessment, regulatory and operational context | Complete |
| Local authority planning portalslocal_planning_portals | official | UK_local | not configured | potential registered | 0 | competing source assessment, regulatory and operational context | Gaps recorded |
| Environment Agency flood monitoring APIea_flood_monitoring | contextual_source | England | not configured | potential registered | 0 | competing source assessment, official meteorology | Complete |
| Ordnance Survey Data Hubos_datahub | contextual_source | Great_Britain | not configured | potential registered | 0 | Not mapped | Complete |
| ONS Open Geography Portalons_geography | contextual_source | UK | not configured | potential registered | 0 | receptor population context | Complete |
| NOMIS / ONS population datanomis | contextual_source | UK | credential present | actual partial | 0 | receptor population context | Complete |
| Index of Multiple Deprivationimd | contextual_source | UK_nation_specific | not configured | potential registered | 0 | Not mapped | Complete |
| Get Information About Schoolsget_information_about_schools | contextual_source | England | not configured | potential registered | 0 | receptor population context | Complete |
| CQC care directorycqc_care_directory | contextual_source | England | not configured | potential registered | 0 | receptor population context | Complete |
| Contracts Findercontracts_finder | contextual_source | UK | not configured | potential registered | 0 | Not mapped | Complete |
| Find a Tender Servicefind_a_tender | contextual_source | UK | not configured | potential registered | 0 | Not mapped | Complete |
| Waste Data Interrogatorwaste_data_interrogator | contextual_source | England | not configured | potential registered | 0 | competing source assessment, regulatory and operational context | Complete |
| WhatDoTheyKnowwhatdotheyknow | secondary_discovery | UK | not configured | potential registered | 0 | Not mapped | Complete |
| ICO decision noticesico_decisions | contextual_source | UK | not configured | potential registered | 0 | Not mapped | Complete |
| OpenStreetMap / Overpassopenstreetmap_overpass | contextual_source | global | not configured | potential registered | 0 | receptor population context | Complete |
| Department for Transport Port Freight Statisticsdft_port_freight | official | UK | not configured | potential registered | 0 | competing source assessment, traffic activity | Complete |
| NASA FIRMS VIIRS and MODIS active fire datanasa_firms | contextual_source | global | records downloaded | actual operational | 313 | competing source assessment, fire and satellite context | Complete |
| UK Pollutant Release and Transfer Registeruk_prtr | official | UK | not configured | potential registered | 0 | competing source assessment, fire and satellite context, regulatory and operational context | Complete |
| Defra Local Air Quality Management and AQMA recordsdefra_aqma | official | UK | not configured | potential registered | 0 | comparator and background, complete provenance, ground measurement quality, uncertainty and missingness | Complete |
| Local authority LAQM annual status and detailed assessment reportslocal_authority_laqm_reports | official | UK_local | not configured | potential registered | 0 | Not mapped | Gaps recorded |
| National Highways WebTRIS traffic datanational_highways_webtris | official | England_strategic_road_network | not configured | potential registered | 0 | competing source assessment, traffic activity | Complete |
| OHID Fingertips Public Health Data APIohid_fingertips | official | England | not configured | potential registered | 0 | aggregate health context, receptor population context | Complete |
| ONS Census and population APIsons_census_api | official | England_and_Wales | not configured | potential registered | 0 | receptor population context | Complete |
| European Environment Agency air quality dataeea_air_quality | official | Europe | not configured | potential registered | 0 | comparator and background, complete provenance, ground measurement quality, specialist scientific context, uncertainty and missingness | Complete |
| EMEP/EBAS atmospheric composition observationsemep_ebas | provider_attributed | Europe_and_global | not configured | potential registered | 0 | comparator and background, document discovery, specialist scientific context | Complete |
| Natural England designated sites datanatural_england_designated_sites | official | England | not configured | potential registered | 0 | receptor population context | Complete |
| CEDA atmospheric and Earth observation archiveceda_archive | contextual_source | UK_and_global | credential present | actual partial | 0 | comparator and background, competing source assessment, fire and satellite context, specialist scientific context | Complete |
| Google Earth Enginegoogle_earth_engine | contextual_source | global | not configured | potential registered | 0 | competing source assessment, fire and satellite context | Complete |
Uncertainty and limitations
- Freshness, missingness, measurement method, spatial representativeness and source independence constrain interpretation.
- Model, satellite, inventory, regulatory, traffic and media records are different evidence classes and are not interchangeable with ground measurements.
- A technical join demonstrates record linkage only; it does not demonstrate contribution or causation.
Questions for scientific review
- Are the selected measurements fresh, quality-eligible and spatially representative for the stated geography?
- Were comparator roles, averaging periods, units and measurement methods shown to be compatible?
- Were meteorology and competing-source evidence aligned to the same time window?
- Which joins were executed against real records, and what were their match and duplicate rates?
- Which plausible alternative explanations remain untested?
These questions are intended to make the output challengeable and reproducible rather than persuasive.
Scientific and legal boundary
Screening evidence only — no causal source attribution, legal or regulatory determination, health finding, safety declaration or compliance conclusion.
Named facilities, operators, permits, roads, fires and planning records are contextual evidence. Inclusion or proximity never implies contribution, fault, breach or causation.
Supporting pages
MethodsSource utilisationEvidence readinessOverall reportCorrections and enquiriesAI and model assurance
Review current deterministic execution, prohibited automated uses, evaluation gates and model provenance.
Scientific evidence and software assurance are different
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: 121; not eligible or not assessed: 6. 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.
What the source counts mean
Registered is not the same as used. Only record-bearing sources are operational, and only sources that passed the project quality-validation contract are quality validated.
54registered / known sources
9operational record-bearing sources
2quality-validated sources
32potential / not-yet-operational sources
Analytical breadth boundary. Registration does not mean a source contributed to the current pollutant statistics.
Evidence categories
| Evidence dimension | Best current stage | Best available sources |
|---|---|---|
| ground measurement quality | quality validated | uk_air_sos_current_particle, laqn_imperial |
| comparator and background | quality validated | uk_air_sos_current_particle, laqn_imperial |
| official meteorology | operational validation pending | met_office_land_observations, met_office_global_spot |
| traffic activity | operational validation pending | dft_road_traffic |
| regional model context | operational validation pending | cams |
| fire and satellite context | operational validation pending | nasa_firms |
| regulatory and operational context | operational validation pending | environment_agency_public_register |
| competing source assessment | operational validation pending | environment_agency_public_register, dft_road_traffic, met_office_land_observations, met_office_global_spot, cams, nasa_firms |
| uncertainty and missingness | quality validated | uk_air_sos_current_particle, laqn_imperial |
| complete provenance | quality validated | uk_air_sos_current_particle, laqn_imperial |
Complete governed source register
| Source | Stage | Authority | Records |
|---|---|---|---|
| Defra UK-AIR Sensor Observation Serviceuk_air_sos_current_particle | quality validated | official | 237 |
| Defra UK-AIR Atom downloadsuk_air_atom | metadata only | official | 0 |
| Imperial College London LAQN APIlaqn_imperial | quality validated | official_network | 654 |
| Environment Agency Public Registerenvironment_agency_public_register | records downloaded | official | 23,559 |
| Planning Data APIplanning_data | not applicable no discovered event | official | 0 |
| National Atmospheric Emissions Inventorynaei | metadata only | official | 0 |
| Department for Transport Road Traffic Statistics APIdft_road_traffic | records downloaded | official | 10,000 |
| OpenAQ v3openaq | metadata only | provider_attributed | 0 |
| World Air Quality Index APIwaqi | not applicable no discovered event | provider_attributed | 0 |
| OpenWeather current conditionsopenweather | not applicable no discovered event | commercial_provider | 0 |
| Met Office Weather DataHub Land Observationsmet_office_land_observations | records downloaded | official | 576 |
| Met Office Weather DataHub Global Spotmet_office_global_spot | records downloaded | official | 10 |
| Copernicus Atmosphere Monitoring Servicecams | records downloaded | official_model | 2 |
| Copernicus Data Space STAC Sentinel-5Pcdse_sentinel5p | metadata only | official | 0 |
| NASA Earthdata Common Metadata Repositorynasa_earthdata_cmr | metadata only | official | 27 |
| PurpleAir APIpurpleair | records downloaded | community_sensor | 286 |
| NewsAPInewsapi | not applicable no discovered event | secondary_discovery | 0 |
| NewsData.ionewsdata | credential present | secondary_discovery | 0 |
| SerpAPIserpapi | credential present | secondary_discovery | 0 |
| Companies House APIcompanies_house | credential present | official | 0 |
| Google Drive legacy archivegoogle_drive | archive disabled | mixed_unverified | 0 |
| OpenAI APIopenai | credential present | derived_non_evidentiary | 0 |
| Gemini APIgemini | credential present | derived_non_evidentiary | 0 |
| UK-AIR Data Selectoruk_air_bulk_historical | not configured | official | 0 |
| SEPA Public Registersepa_public_register | not configured | official | 0 |
| Natural Resources Wales Public Registernrw_public_register | not configured | official | 0 |
| Northern Ireland environmental regulation recordsniea_records | not configured | official | 0 |
| Local authority planning portalslocal_planning_portals | not configured | official | 0 |
| Environment Agency flood monitoring APIea_flood_monitoring | not configured | contextual_source | 0 |
| Ordnance Survey Data Hubos_datahub | not configured | contextual_source | 0 |
| ONS Open Geography Portalons_geography | not configured | contextual_source | 0 |
| NOMIS / ONS population datanomis | credential present | contextual_source | 0 |
| Index of Multiple Deprivationimd | not configured | contextual_source | 0 |
| Get Information About Schoolsget_information_about_schools | not configured | contextual_source | 0 |
| CQC care directorycqc_care_directory | not configured | contextual_source | 0 |
| Contracts Findercontracts_finder | not configured | contextual_source | 0 |
| Find a Tender Servicefind_a_tender | not configured | contextual_source | 0 |
| Waste Data Interrogatorwaste_data_interrogator | not configured | contextual_source | 0 |
| WhatDoTheyKnowwhatdotheyknow | not configured | secondary_discovery | 0 |
| ICO decision noticesico_decisions | not configured | contextual_source | 0 |
| OpenStreetMap / Overpassopenstreetmap_overpass | not configured | contextual_source | 0 |
| Department for Transport Port Freight Statisticsdft_port_freight | not configured | official | 0 |
| NASA FIRMS VIIRS and MODIS active fire datanasa_firms | records downloaded | contextual_source | 313 |
| UK Pollutant Release and Transfer Registeruk_prtr | not configured | official | 0 |
| Defra Local Air Quality Management and AQMA recordsdefra_aqma | not configured | official | 0 |
| Local authority LAQM annual status and detailed assessment reportslocal_authority_laqm_reports | not configured | official | 0 |
| National Highways WebTRIS traffic datanational_highways_webtris | not configured | official | 0 |
| OHID Fingertips Public Health Data APIohid_fingertips | not configured | official | 0 |
| ONS Census and population APIsons_census_api | not configured | official | 0 |
| European Environment Agency air quality dataeea_air_quality | not configured | official | 0 |
| EMEP/EBAS atmospheric composition observationsemep_ebas | not configured | provider_attributed | 0 |
| Natural England designated sites datanatural_england_designated_sites | not configured | official | 0 |
| CEDA atmospheric and Earth observation archiveceda_archive | credential present | contextual_source | 0 |
| Google Earth Enginegoogle_earth_engine | not configured | contextual_source | 0 |
Cross-source joins
Routine convergence is separate from episode investigation. This build formed 237 ordinary observation rows and executed 2 of 2 applicable routine meteorology/comparator joins; 0 were fully validated. The configured episode/research register separately records 0 of 11 joins executed and 0 technically validated. A zero episode count or a not-applicable episode join is not evidence that routine cross-source capability is absent. Join-ready means inputs/contracts exist, not that the join was executed or scientifically validated.
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.
234 / 237reporting / identified series
128current 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
42recent 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.