The National Disaster-Warning Case Study on heain-core PM2.5 in Chiang Mai and Bangkok, the 2026 Season Replaying a Five-Month Chronic Hazard on a 37-Node Simulation: Community Sensors, Standards and Burn Quotas, with Core C8

Abstract PM2.5 differs from the hazards of earlier volumes: it is chronic, lasts months, returns every year, and often comes from outside the area it harms. In the 2026 season Chiang Mai had 11,023 hotspots and 53 days above 37.5 µg/m³ [8]; Bangkok used Cell Broadcast to warn people entering red zones on 14–15 January 2026 [9]; and the clean-air bill, which gives provinces a larger role, is not yet law [11]. This Volume 6 of the case study [1] reports the replay of this season (event series E4). The author replayed 1 January–31 May 2026 at 1 day = 1 minute on a 37-node layout adding Chiang Mai province, Mueang district (an official station and 30 synthetic community sensors) and Chiang Dao district (a fire watch and burn permits), in two runs: "as it happened" and "with HEAIN". Requirements R31–R40 test cheap sensors, national and provincial standards, a chronic hazard, sources outside the area, burn quotas, school closures, case evidence, health data and months of readings. The first run on core C7 found the two expected gaps: a province could set a standard looser than the nation's (60), and P5 approved permits one at a time without counting, so 41 went over the quota. Core C8 (3329b2f) added p5.threshold_direction, which lets a lower tier only tighten, and p5.quota, which counts approvals per Zone per period. After the fix the HEAIN run passed 28 of 28 checks with no gap. Warnings and school closures on cheap sensors alone fell to zero (from 9 and 8); messages to Mueang Chiang Mai changed from 62 new Alerts to 5 Alerts, 51 Updates and 5 Cancels; permits on bad-air days and over the quota fell to zero (from 33 and 41); and all 75 case records were kept. All figures come from a simulation on one machine. Keywords: HEAIN Framework, heain-core, PM2.5, Chiang Mai, Bangkok, Chronic Hazard, Low-cost Sensors, Corroboration, Decentralisation, Threshold Direction, P5 Quota, Burn Permits, Alert Fatigue