1001 Smart Cities
🇨🇳 Beijing

High-density air-quality monitoring and source-apportionment network

🤖 AI-generated summary of the sources below · 🔎 Last verified · ◆ 11 sourced claims, none individually verified yet

This overview was generated with AI from the public sources listed below and checked against them before publication. It has not had a complete human fact-check — treat it as a starting point and follow the sources.

How this atlas is made · What “last verified” means · What “source-checked” means · The full record behind this page

✎ Corrected 27 Aug 2026 Publication date recorded for 1 source. · 2 revisions in all What changed →

Beijing began publishing real-time PM2.5 readings in 2013 and has since built a two-tier network: 35 standard stations measuring six pollutants continuously, and — from 2016 — more than 1,000 compact sensors across communities and townships, backed by satellite remote sensing and laser radar. The municipal monitoring centre runs an analytical system that resolves around 125 components of PM2.5 to trace sources, and feeds a linkage model that forwards suspected pollution to enforcement departments. What the network decides is where inspectors go.

Live 📅 since 2013
Outcome🎯 Succeeded
Evidence📊 Independent
what does this mean?The strongest source is an independent non-academic evaluation: an audit office, a government or EU review, or an NGO. It grades who did the looking — not how well the project went. All four grades →
Run byBeijing Ecology and Environment Bureau
Scale🏙️ City-wide

📊 Impact

UNEP's 2019 review found Beijing's fine particulate pollution fell by 35% between 2013 and the end of 2017, and by 25% in the surrounding Beijing-Tianjin-Hebei region, and credited coal-boiler controls, cleaner domestic fuels and industrial restructuring for much of it rather than the instruments. The city's own monitoring centre reports the annual mean falling from 89.5 micrograms per cubic metre in 2013 to 27 in 2025, and heavily polluted days from 58 to one. The network's own product is targeting: the latest source apportionment puts 57% of Beijing's PM2.5 on regional transport and the remaining 43% on local sources, led by vehicle and residential emissions.

🎓 Lesson

Density buys resolution, not cleaner air. The compact sensors arrived in 2016, three years after the decline began, and the independent review credits boilers, fuel and factories for it. What the network changed is the address of the next inspection — and then the address of the argument: once apportionment puts most of the remaining particles on transport from outside the city, the work left is regional, and no municipal instrument can shorten it.

🌱 EnvironmentAir qualitySensors & IoTOpen data

Sources

↗ UNEP — A Review of 20 Years' Air Pollution Control in Beijing (independent)Published 29 June 2019 archived copyIndependent review of two decades of air-pollution control in Beijing; source for the ~35% PM2.5 decline over 2013-2017 and the ~25% regional decline, both quoted by the Climate & Clean Air Coalition. The report page states 29 June 2019.
↗ ICLEI — Clearing the skies (independent)Published 1 September 2023Independent account of the integrated network: created in 2016, using high-resolution satellite remote sensing and laser radar, with over 1,000 sensors distributed across the city.
↗ Climate & Clean Air Coalition (independent)Published 9 March 2019Quotes the UNEP review's headline findings and attributes much of the reduction to coal-boiler controls, cleaner domestic fuels and industrial restructuring.
↗ Xinhua — How technology boosts Beijing’s air pollution governance (state news agency)Published 8 August 2026Beijing Municipal Ecological and Environmental Monitoring Centre figures relayed by the state news agency: 35 standard stations and more than 1,000 compact sensors, ~125 PM2.5 components resolved, the regulation-monitoring-inspection linkage model, and the annual mean falling from 89.5 to 27 micrograms per cubic metre between 2013 and 2025.

📅 How old is the evidence?

Two clocks, kept apart: when this entry’s sources were published, and what has happened to its record in the atlas. Documented span: since 2013. 4 of 4 sources carry a publication date, from 9 March 2019 to 8 August 2026.

When the sources were published

  1. Climate and Clean Air Coalition (CCAC) · international organisationClimate & Clean Air Coalition (independent)
  2. UN Environment Programme (UNEP) · international organisationUNEP — A Review of 20 Years' Air Pollution Control in Beijing (independent)
  3. ICLEI – Local Governments for Sustainability · ngoICLEI — Clearing the skies (independent)
  4. Xinhua News Agency · pressXinhua — How technology boosts Beijing’s air pollution governance (state news agency)

Every source, with links ↑

What happened to this record

  1. Entered the record
  2. 1 source added
  3. Sources last read
  4. Publication date recorded for 1 source

Every revision, permanent →

Show your work What this page rests on and what it can’t tell you · all 11 claims with their sources · the forensic record

Evidence Passport · public beta 11 addressable claims, 4 source dossiers, one permanent baseline. The passport is unreviewed — an AI-assisted structural migration, not a human or expert endorsement. Every revision keeps a permanent copy under revision history.

Inspect the claims, one by one — verbatim text, sources and caveats for all 11

The text below is copied verbatim from the published record. Each claim names the source dossiers that carry it; caveats stay attached to the claim they qualify.

Claim 1 clm-658968e5e4b7710c quantitative
Beijing began publishing real-time PM2.5 readings in 2013
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Xinhua, citing the municipal monitoring centre: 'compared with 58 heavily polluted days in 2013, when the city officially began releasing PM2.5 monitoring data'.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Xinhua — How technology boosts Beijing’s air pollution governance (state news agency)
Claim 2 clm-0f149e2f6edc9044 quantitative
35 standard stations measuring six pollutants continuously
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Xinhua: 'Figures show 35 standard monitoring stations across the city continuously measure six major pollutants'.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Xinhua — How technology boosts Beijing’s air pollution governance (state news agency)
Claim 3 clm-48aa7becd965228d quantitative
and — from 2016 — more than 1,000 compact sensors across communities and townships, backed by satellite remote sensing and laser radar
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
ICLEI: 'In 2016, a cutting-edge integrated air quality monitoring network was created, utilizing advanced technologies such as high-resolution satellite remote sensing and laser radar. In Beijing, a dense PM2.5 monitoring network was set up, with over 1000 sensors distributed across the city.' Xinhua gives the current figure as 'more than 1,000 compact sensors deployed across communities and townships'.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. ICLEI — Clearing the skies (independent)
  2. Xinhua — How technology boosts Beijing’s air pollution governance (state news agency)
Claim 4 clm-856d48f684749027 quantitative
an analytical system that resolves around 125 components of PM2.5 to trace sources
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Xinhua: 'The center has developed an analytical system that can identify around 125 components of PM2.5, covering most of its composition and helping researchers trace pollution sources.'
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Xinhua — How technology boosts Beijing’s air pollution governance (state news agency)
Claim 5 clm-049637deb028dd27 descriptive
feeds a linkage model that forwards suspected pollution to enforcement departments
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Xinhua: 'Using more than 30 intelligent algorithms, the platform automatically analyzes data and identifies potential pollution risks, based on which monitoring staff identify the most pressing problems and forward them to enforcement departments.'
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Xinhua — How technology boosts Beijing’s air pollution governance (state news agency)
Claim 6 clm-8949cdf50d19cab6 quantitative
UNEP's 2019 review found Beijing's fine particulate pollution fell by 35% between 2013 and the end of 2017, and by 25% in the surrounding Beijing-Tianjin-Hebei region
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The Climate & Clean Air Coalition, quoting the UNEP review: 'In 2013 Beijing adopted more systematic and intensive measures for air pollution control. By the end of 2017 fine particulate pollution (PM2.5) fell by 35% and by 25% in the surrounding Beijing-Tianjin-Hebei region.'
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. UNEP — A Review of 20 Years' Air Pollution Control in Beijing (independent)
  2. Climate & Clean Air Coalition (independent)
Claim 7 clm-77183db29b82ae10 descriptive
credited coal-boiler controls, cleaner domestic fuels and industrial restructuring for much of it rather than the instruments
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
CCAC: 'Much of this reduction came from measures to control coal-fired boilers, provide cleaner domestic fuels, and industrial restructuring.'
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Climate & Clean Air Coalition (independent)
Claim 8 clm-a81c66dfbb2ac036 quantitative
The city's own monitoring centre reports the annual mean falling from 89.5 micrograms per cubic metre in 2013 to 27 in 2025, and heavily polluted days from 58 to one
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Xinhua: 'The annual average PM2.5 concentration … fell from 89.5 micrograms per cubic meter in 2013 to 27 micrograms per cubic meter in 2025, a decline of nearly 70 percent' and 'In 2025, Beijing recorded 311 days with good air quality and only one heavily polluted day, compared with 58 heavily polluted days in 2013'.
Caveat
The operator's own figures, relayed by the state news agency; no independent verification of the 2025 value has been published.

Sources carrying this claim

  1. Xinhua — How technology boosts Beijing’s air pollution governance (state news agency)
Claim 9 clm-ccaeebf7b11f6633 quantitative
the latest source apportionment puts 57% of Beijing's PM2.5 on regional transport and the remaining 43% on local sources, led by vehicle and residential emissions
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Xinhua: 'The latest analysis showed that regional transport contributed 57 percent of Beijing's PM2.5 pollution. Among local sources that accounted for the remaining 43 percent, vehicle emissions and residential sources represented the largest share of pollution.'
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Xinhua — How technology boosts Beijing’s air pollution governance (state news agency)
Claim 10 clm-ac727549a4d5e0d6 quantitative
The compact sensors arrived in 2016, three years after the decline began
Published field
lesson · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
ICLEI dates the integrated network with over 1,000 sensors to 2016; the CCAC dates the intensified control measures and the measured decline to 2013.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. ICLEI — Clearing the skies (independent)
  2. Climate & Clean Air Coalition (independent)
Claim 11 clm-34556852de7e046c descriptive
once apportionment puts most of the remaining particles on transport from outside the city, the work left is regional
Published field
lesson · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The 57%/43% split between regional transport and local sources is the monitoring centre's own latest apportionment as reported by Xinhua.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Xinhua — How technology boosts Beijing’s air pollution governance (state news agency)
Forensic record — source dossiers, gaps, hashes and the exact revision this page renders

This layer records what is known about each source, what is still missing, and the exact snapshot this page is rendering. A missing date, archive or hash stays visible as missing.

unreviewed Revision 2026-08-27-source-dating effective 2026-08-26 · created 2026-08-27

Awaiting operator and domain-expert review; publication of this revision implies neither.

sha256:607a2cfae4cc734ee407a16456a621e6f0bcb2eb8d5368a138332385f7d797fd
Revision history → Permanent version link → Machine-readable record → Evidence Constitution →
11
of 11 claims mapped
4
source dossiers
4
publication dates recorded
1
archives linked
0
exact locators
0
content captures hashed

Governance facts carried by the record

Operator
Beijing Ecology and Environment Bureau
Actor types
city-government
Funding model
Not recorded
Funding description
Not recorded
Cost
Not recorded
Ownership
Not recorded
Decision rights
Not recorded
Exit conditions
Not recorded

4 source dossiers

UNEP — A Review of 20 Years' Air Pollution Control in Beijing (independent) unep.org · 1 linked claim

Open original source ↗

Stable source ID
src-89d5da7d0e10b635
Publisher
Name not classified · unep.org
Type / language
web-page · language not classified
Published
2019-06-29
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
Open archived copy ↗ · 2026-01-19
Content hash
No captured content hash
Locator
Open the recorded source note

Independent review of two decades of air-pollution control in Beijing; source for the ~35% PM2.5 decline over 2013-2017 and the ~25% regional decline, both quoted by the Climate & Clean Air Coalition. The report page states 29 June 2019.

Descriptive only — not page/paragraph exact
Claims linked
ICLEI — Clearing the skies (independent) sustainablemobility.iclei.org · 2 linked claims

Open original source ↗

Stable source ID
src-ec7e146ac8042367
Publisher
Name not classified · sustainablemobility.iclei.org
Type / language
web-page · language not classified
Published
2023-09-01
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Independent account of the integrated network: created in 2016, using high-resolution satellite remote sensing and laser radar, with over 1,000 sensors distributed across the city.

Descriptive only — not page/paragraph exact
Claims linked
Climate & Clean Air Coalition (independent) ccacoalition.org · 3 linked claims

Open original source ↗

Stable source ID
src-3f3768226a3bbd4d
Publisher
Name not classified · ccacoalition.org
Type / language
web-page · language not classified
Published
2019-03-09
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Quotes the UNEP review's headline findings and attributes much of the reduction to coal-boiler controls, cleaner domestic fuels and industrial restructuring.

Descriptive only — not page/paragraph exact
Claims linked
Xinhua — How technology boosts Beijing’s air pollution governance (state news agency) english.news.cn · 8 linked claims

Open original source ↗

Stable source ID
src-9dc84c1a1fa08b51
Publisher
Name not classified · english.news.cn
Type / language
web-page · language not classified
Published
2026-08-08
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-27
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Beijing Municipal Ecological and Environmental Monitoring Centre figures relayed by the state news agency: 35 standard stations and more than 1,000 compact sensors, ~125 PM2.5 components resolved, the regulation-monitoring-inspection linkage model, and the annual mean falling from 89.5 to 27 micrograms per cubic metre between 2013 and 2025.

Descriptive only — not page/paragraph exact
Claims linked
Known limits of this passport
  • Publisher names and source languages have not yet been classified; domains are recorded without guessing.
  • Existing source notes are descriptive locators, not page- or paragraph-exact citations.
  • A missing archive, publication date or content hash is shown as null rather than inferred.
  • The project-level evidence grade ranks the strongest source in the entry; it is not a truth score for every claim.

Continue exploring

Compare this project

🇬🇧 Breathe London Air-Quality Sensor Network · London Two dense air-sensor networks: Beijing's 1,000+ grid sensors drive 'precise' control; Breathe London's 400+ nodes stream free data. 🇺🇸 Array of Things · Chicago Two urban air-sensing networks: Beijing runs 1,000+ grid sensors since 2013; Chicago's pole array measured air and noise 2016–21. 🇳🇵 Kathmandu Metropolitan Air Quality Monitoring Dashboard · Kathmandu Air monitoring at opposite scales: Beijing's 1,000+ sensors, PM2.5 down ~35% (2013–17); Kathmandu's first Nepali network, 18 nodes (2025).

Explore the wider context

📟 A Reading Is Not a Decision🌫️ Air quality guide🏙️ Beijing city profile🌱 Environment projects📖 Air quality index (AQI)📖 Low-emission zone📖 Open data
📎 Cite this project

1001 Smart Cities (2026). “High-density air-quality monitoring and source-apportionment network” — Beijing, China. The Smart City Atlas. https://1001smartcities.org/projects/beijing-air-monitoring/ (last verified 2026-08-26). Data: CC BY 4.0.

The underlying data is free to reuse with attribution — see the open data page.

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