1001 Smart Cities
🇹🇭 Bangkok

Bangkok PM2.5 Monitoring & Graduated Response

🤖 AI-generated summary · ◆ 9 sourced claims · 🔎 Last verified

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.

9 sourced claims on this page, none individually verified yet — turn on “Sources in the text” to see each one.

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

✎ Updated 22 Aug 2026 Publication date recorded for 10 sources. What changed →

Red on the index closes the city's own schools and bars unregistered lorries from nine inner districts. Employers can only be asked. And enforcement is thin: 1,547 recorded violations produced 28 fines.

Outcome🔄 Ongoing
Evidence🏛️ Official
what does this mean?The strongest source is the operator's or the city's own reporting — an official report, dataset or press release. It grades who did the looking — not how well the project went. All four grades →
Run byBangkok Metropolitan Administration (Environment Department)
Scale🏙️ City-wide
FundingCity budget; the January 2025 free-transit week was paid separately by the national government (140 million baht)

Part of 1001 Smart Cities — 1,167 documented projects · 🏙️ 9 more in Bangkok · 🌫️ Air quality guide · 🌱 Environment projects

Bangkok's city government publishes readings from 523 monitoring points, 70 of them fixed stations, and colours every district against the national index tightened in June 2023: orange above 37.5 micrograms, red above 75.1. Red carries consequences. On 24 January 2025 the city closed 352 of its 437 schools, and trucks not on a pre-registered Green List were barred from nine inner districts; the national government made trains and buses free for a week for 140 million baht. Employer work-from-home stays voluntary, and a peer-reviewed model traces roughly 30% of the region's haze-season PM2.5 to burning outside Thailand.

Live 📅 since 2023

📊 Impact

The city reported that its 23-24 January 2025 low-emission-zone pilot inside the Ratchadaphisek ring road kept 404 trucks a day out of the zone and left PM2.5 15.6% below surrounding areas. Enforcement was thin: 1,547 recorded violations produced 28 fines.

🎓 Lesson

A threshold bites only where the city holds the legal lever. Bangkok can close its own schools outright and, borrowing disaster-law powers, turn lorries back, but it can only ask employers to send staff home, and it cannot reach the burning upwind.

🌱 EnvironmentAir qualitySensors & IoTHealth & careTraffic managementPublic transport

Sources

↗ Greener Bangkok — air quality monitoring stationsThe city's own page: 523 air-quality monitoring points citywide, of which 70 are fixed monitoring stations; distinguishes reference-grade instruments from portable devices.
↗ Greener Bangkok — the work-from-home networkOfficial page for the voluntary work-from-home network: employers register online, and the city alerts them when PM2.5 exceeds 75 micrograms per cubic metre for three consecutive days. Enrolment figures differ between the city page and press copy, so none is used.
↗ Pollution Control Department — revised national air quality indexAnnouncement of Thailand's revised air quality index in the Royal Gazette, lowering the red band to 75.1 micrograms per cubic metre, effective 1 June 2023.
↗ AFP via Phys.org — Bangkok closes schools over air pollution352 of 437 city schools closed on 24 January 2025, the most in five years, with more than 250 closed the previous day; PM2.5 reached 108 micrograms per cubic metre.
↗ Nation Thailand — polluting trucks barred from inner BangkokPublished 22 January 2025Dates and geography of the truck ban: unregistered six-wheel and larger vehicles barred on 23-24 January 2025 from nine districts inside the Ratchadaphisek ring road plus 13 outer districts.
Show 5 more sourcesShow fewer
↗ Nation Thailand — low-emission zone plan for fiscal 2026Published 19 December 2025Plan presented 19 December 2025 for 50 districts; the trigger thresholds and ventilation-rate condition; 57,936 Green List registrations; and the pilot results of 404 fewer trucks a day, 15.6% lower PM2.5, 1,547 violations and 28 fines.
↗ Bangkok Post — the legal basis for the truck banPublished 29 October 2024The governor states the city has no authority over traffic and will enforce the truck ban under the Disaster Prevention and Mitigation Act, triggered by the red level of 75 micrograms in five districts. Site blocks automated fetching; headline and content confirmed via search.
↗ Government Public Relations Department — seven days of free public transportOfficial announcement of free public transport from 25 to 31 January 2025, with 140 million baht allocated to compensate rail and bus operators. Ordered by the national government, not the city.
↗ Bangkok Post — free public transport plan under firePublished 26 January 2025Counterweight: a Chulalongkorn University environmental academic calls the 140-million-baht free-fare week a waste of money that does not change car users' behaviour. Site blocks automated fetching; content confirmed via search.
↗ Source attribution and health burden of PM2.5 in mainland Thailand (peer-reviewed)Chemical-transport source attribution for the Bangkok metropolitan region: foreign biomass burning contributes about 30%, and inflow across the model boundary rises from about 30% in February to around 50% in March and April. A separate study using the same model family finds domestic industry and transport dominant, so the figure is attributed to this model rather than asserted.

📅 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 2023. 4 of 10 sources carry a publication date, from 29 October 2024 to 19 December 2025.

When the sources were published

  1. Bangkok Post · pressBangkok Post — the legal basis for the truck ban
  2. The Nation (Thailand) · pressNation Thailand — polluting trucks barred from inner Bangkok
  3. Bangkok Post · pressBangkok Post — free public transport plan under fire
  4. The Nation (Thailand) · pressNation Thailand — low-emission zone plan for fiscal 2026

Every source, with links ↑

What happened to this record

  1. Sources last read
  2. Entered the record
  3. Publication date recorded for 10 sources

Every revision, permanent →

Show your work What this page rests on and what it can’t tell you · all 9 claims with their sources · the forensic record

Evidence Passport · public beta 9 addressable claims, 10 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 9

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-747135a8bf62c677 quantitative
Bangkok's city government publishes readings from 523 monitoring points, 70 of them fixed stations
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The city's own page gives 523 air-quality monitoring points citywide, of which 70 are fixed monitoring stations, and distinguishes reference-grade instruments from portable devices.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Greener Bangkok — air quality monitoring stations
Claim 2 clm-3932e79aec8c60e1 quantitative
colours every district against the national index tightened in June 2023: orange above 37.5 micrograms, red above 75.1
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Thailand's revised air quality index, announced in the Royal Gazette, lowered the red band to 75.1 micrograms per cubic metre with effect from 1 June 2023.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Pollution Control Department — revised national air quality index
Claim 3 clm-2b15ec6222fd51bf quantitative
On 24 January 2025 the city closed 352 of its 437 schools
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The agency report records 352 of 437 city schools closed on 24 January 2025 — the most in five years, with more than 250 closed the previous day — as PM2.5 reached 108 micrograms per cubic metre.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. AFP via Phys.org — Bangkok closes schools over air pollution
Claim 4 clm-ac6f842e62438476 descriptive
trucks not on a pre-registered Green List were barred from nine inner districts
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Unregistered six-wheel and larger vehicles were barred on 23-24 January 2025 from nine districts inside the Ratchadaphisek ring road plus 13 outer districts. The governor states that the city has no authority over traffic and enforces the ban under the Disaster Prevention and Mitigation Act, triggered by the red level of 75 micrograms in five districts.
Caveat
The Bangkok Post page blocks automated fetching; headline and content were confirmed via search. The borrowed legal basis is the point: the lever is disaster law, not traffic law.

Sources carrying this claim

  1. Nation Thailand — polluting trucks barred from inner Bangkok
  2. Bangkok Post — the legal basis for the truck ban
Claim 5 clm-56175448ce8d2a4d quantitative
the national government made trains and buses free for a week for 140 million baht
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The official announcement covers free public transport from 25 to 31 January 2025 with 140 million baht allocated to compensate rail and bus operators, ordered by the national government rather than the city.
Caveat
A university environmental academic calls the free-fare week a waste of money that does not change car users' behaviour; that page also blocks automated fetching and was confirmed via search.

Sources carrying this claim

  1. Government Public Relations Department — seven days of free public transport
  2. Bangkok Post — free public transport plan under fire
Claim 6 clm-c8d5da22e83c4b14 descriptive
Employer work-from-home stays voluntary
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The official page describes a voluntary network: employers register online, and the city alerts them when PM2.5 exceeds 75 micrograms per cubic metre for three consecutive days.
Caveat
Enrolment figures differ between the city page and press copy, so none is used.

Sources carrying this claim

  1. Greener Bangkok — the work-from-home network
Claim 7 clm-980f6c9521ab750c quantitative
a peer-reviewed model traces roughly 30% of the region's haze-season PM2.5 to burning outside Thailand
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The chemical-transport source attribution for the Bangkok metropolitan region puts foreign biomass burning at about 30 per cent, with inflow across the model boundary rising from about 30 per cent in February to around 50 per cent in March and April.
Caveat
A separate study using the same model family finds domestic industry and transport dominant, so the figure is attributed to this model rather than asserted.

Sources carrying this claim

  1. Source attribution and health burden of PM2.5 in mainland Thailand (peer-reviewed)
Claim 8 clm-7e1c6d84be1f80a7 quantitative
The city reported that its 23-24 January 2025 low-emission-zone pilot inside the Ratchadaphisek ring road kept 404 trucks a day out of the zone and left PM2.5 15.6% below surrounding areas. Enforcement was thin: 1,547 recorded violations produced 28 fines
Published field
impact · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The plan presented on 19 December 2025 for 50 districts carries the pilot results: 404 fewer trucks a day, 15.6 per cent lower PM2.5, 1,547 violations and 28 fines, alongside 57,936 Green List registrations and the trigger thresholds and ventilation-rate condition.
Caveat
City-reported pilot figures over two days, presented in support of an expansion plan.

Sources carrying this claim

  1. Nation Thailand — low-emission zone plan for fiscal 2026
Claim 9 clm-db28a5e8cc036c74 descriptive
Bangkok can close its own schools outright and, borrowing disaster-law powers, turn lorries back, but it can only ask employers to send staff home, and it cannot reach the burning upwind
Published field
lesson · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Four levers of visibly different strength: the city closed 352 of its own 437 schools by its own decision; it enforced the truck ban only by borrowing powers under the Disaster Prevention and Mitigation Act, the governor stating the city has no authority over traffic; the work-from-home network is registration-based and advisory; and roughly 30 per cent of haze-season PM2.5 in the region is modelled as arriving from outside the country.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. AFP via Phys.org — Bangkok closes schools over air pollution
  2. Bangkok Post — the legal basis for the truck ban
  3. Greener Bangkok — the work-from-home network
  4. Source attribution and health burden of PM2.5 in mainland Thailand (peer-reviewed)
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 2026-08-21-source-dates effective 2026-07-26 · created 2026-08-22

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

sha256:952c76385cbd7fe87eb90cfaf8c07e3213a7cab409599a915fc6c2e131a5d65b
Revision history → Permanent version link → Machine-readable record → Evidence Constitution →
9
of 9 claims mapped
10
source dossiers
4
publication dates recorded
0
archives linked
0
exact locators
0
content captures hashed

Governance facts carried by the record

Operator
Bangkok Metropolitan Administration (Environment Department)
Actor types
city-government
Funding model
public
Funding description
City budget; the January 2025 free-transit week was paid separately by the national government (140 million baht)
Cost
Not recorded
Ownership
Not recorded
Decision rights
Not recorded
Exit conditions
Not recorded

10 source dossiers

Greener Bangkok — air quality monitoring stations greener.bangkok.go.th · 1 linked claim

Open original source ↗

Stable source ID
src-155e13f7db2824c2
Publisher
Name not classified · greener.bangkok.go.th
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The city's own page: 523 air-quality monitoring points citywide, of which 70 are fixed monitoring stations; distinguishes reference-grade instruments from portable devices.

Descriptive only — not page/paragraph exact
Claims linked
Greener Bangkok — the work-from-home network greener.bangkok.go.th · 2 linked claims

Open original source ↗

Stable source ID
src-b13aa042335c4b8b
Publisher
Name not classified · greener.bangkok.go.th
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Official page for the voluntary work-from-home network: employers register online, and the city alerts them when PM2.5 exceeds 75 micrograms per cubic metre for three consecutive days. Enrolment figures differ between the city page and press copy, so none is used.

Descriptive only — not page/paragraph exact
Claims linked
Pollution Control Department — revised national air quality index pcd.go.th · 1 linked claim

Open original source ↗

Stable source ID
src-ffa194ad11806903
Publisher
Name not classified · pcd.go.th
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Announcement of Thailand's revised air quality index in the Royal Gazette, lowering the red band to 75.1 micrograms per cubic metre, effective 1 June 2023.

Descriptive only — not page/paragraph exact
Claims linked
AFP via Phys.org — Bangkok closes schools over air pollution phys.org · 2 linked claims

Open original source ↗

Stable source ID
src-337e69b349709542
Publisher
Name not classified · phys.org
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

352 of 437 city schools closed on 24 January 2025, the most in five years, with more than 250 closed the previous day; PM2.5 reached 108 micrograms per cubic metre.

Descriptive only — not page/paragraph exact
Claims linked
Nation Thailand — polluting trucks barred from inner Bangkok nationthailand.com · 1 linked claim

Open original source ↗

Stable source ID
src-dcfb2c71d4bd9fb2
Publisher
Name not classified · nationthailand.com
Type / language
web-page · language not classified
Published
2025-01-22
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Dates and geography of the truck ban: unregistered six-wheel and larger vehicles barred on 23-24 January 2025 from nine districts inside the Ratchadaphisek ring road plus 13 outer districts.

Descriptive only — not page/paragraph exact
Claims linked
Nation Thailand — low-emission zone plan for fiscal 2026 nationthailand.com · 1 linked claim

Open original source ↗

Stable source ID
src-324ab1566613262f
Publisher
Name not classified · nationthailand.com
Type / language
web-page · language not classified
Published
2025-12-19
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Plan presented 19 December 2025 for 50 districts; the trigger thresholds and ventilation-rate condition; 57,936 Green List registrations; and the pilot results of 404 fewer trucks a day, 15.6% lower PM2.5, 1,547 violations and 28 fines.

Descriptive only — not page/paragraph exact
Claims linked
Bangkok Post — the legal basis for the truck ban bangkokpost.com · 2 linked claims

Open original source ↗

Stable source ID
src-4631389c10cc0bfc
Publisher
Name not classified · bangkokpost.com
Type / language
web-page · language not classified
Published
2024-10-29
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The governor states the city has no authority over traffic and will enforce the truck ban under the Disaster Prevention and Mitigation Act, triggered by the red level of 75 micrograms in five districts. Site blocks automated fetching; headline and content confirmed via search.

Descriptive only — not page/paragraph exact
Claims linked
Government Public Relations Department — seven days of free public transport thailand.prd.go.th · 1 linked claim

Open original source ↗

Stable source ID
src-debdf84ab03bc6a1
Publisher
Name not classified · thailand.prd.go.th
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Official announcement of free public transport from 25 to 31 January 2025, with 140 million baht allocated to compensate rail and bus operators. Ordered by the national government, not the city.

Descriptive only — not page/paragraph exact
Claims linked
Bangkok Post — free public transport plan under fire bangkokpost.com · 1 linked claim

Open original source ↗

Stable source ID
src-93ae977a022073cd
Publisher
Name not classified · bangkokpost.com
Type / language
web-page · language not classified
Published
2025-01-26
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Counterweight: a Chulalongkorn University environmental academic calls the 140-million-baht free-fare week a waste of money that does not change car users' behaviour. Site blocks automated fetching; content confirmed via search.

Descriptive only — not page/paragraph exact
Claims linked
Source attribution and health burden of PM2.5 in mainland Thailand (peer-reviewed) pmc.ncbi.nlm.nih.gov · 2 linked claims

Open original source ↗

Stable source ID
src-c3843003beaba62b
Publisher
Name not classified · pmc.ncbi.nlm.nih.gov
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-07-26
Dossier created
2026-08-22
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Chemical-transport source attribution for the Bangkok metropolitan region: foreign biomass burning contributes about 30%, and inflow across the model boundary rises from about 30% in February to around 50% in March and April. A separate study using the same model family finds domestic industry and transport dominant, so the figure is attributed to this model rather than asserted.

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

🇮🇳 GRAP: Air Quality Readings as a Legal Trigger · New Delhi Both let a reading act: Delhi's AQI stages trigger bans by law, Bangkok borrows disaster-law powers because it has no traffic authority. 🇮🇩 Court-Ordered Air Quality Monitoring · Jakarta Jakarta's court-ordered network measures and stops there; Bangkok's red level closes its own schools and turns lorries back. 🇪🇸 ZBE Rondes de Barcelona Low Emission Zone · Barcelona Barcelona bans dirty vehicles permanently by camera; Bangkok's truck ban lasted two days and produced 28 fines from 1,547 violations.

Does the air reading have a consequence?

The same ladder that organises the flood systems in this atlas, applied to air. All four cities measure well. What separates them is whether a number is allowed to oblige anyone to do anything.

ProjectSinceStatusOutcomeEvidenceRun byCostWhat follows from the reading
GRAP: Air Quality Readings as a Legal TriggerNew Delhi, 🇮🇳 2017 Live Ongoing Independent National government, City government, Research institution not public The measurement obliges: an index crossing a fixed step brings legal duties into force by itself, from construction bans to school closures.
Critical Episode Management: A Next-Day Forecast With Legal ForceSantiago, 🇨🇱 1997 Live Ongoing Official National government, Regional government not public The threshold binds but the day is judged — an appointed regional authority signs the declaration, and it acts on a forecast of tomorrow rather than a reading of today.
Bangkok PM2.5 Monitoring & Graduated ResponseBangkok, 🇹🇭 2023 Live Ongoing Official City government not public The city can close its own schools on a reading, must borrow the disaster act to keep trucks out, and can only ask employers.
Court-Ordered Air Quality MonitoringJakarta, 🇮🇩 2021 Live Ongoing Independent City government not public A court ordered the network and the network was built — but no index value triggers anything at all.

Explore the wider context

📟 A Reading Is Not a Decision📖 Air quality index (AQI)📖 Adaptive traffic signals📖 Automated speed enforcement (speed cameras)
📎 Cite this project

1001 Smart Cities (2026). “Bangkok PM2.5 Monitoring & Graduated Response” — Bangkok, Thailand. The Smart City Atlas. https://1001smartcities.org/projects/bangkok-pm25-response/ (last verified 2026-07-26). Data: CC BY 4.0.

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

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