Sensor Readings & Environmental Telemetry
PM2.5 & PM10 Particulate Matter
Understanding the primary airborne hazard in British Columbia wildfire smoke.
Particulate Matter (PM) describes microscopic solid particles and liquid droplets suspended in the air. During BC wildfire seasons, biomass combustion creates dense plumes composed primarily of PM2.5 (fine particles smaller than 2.5 micrometres) and PM10 (coarse dust and ash up to 10 micrometres).
Because PM2.5 particles are approximately 1/30th the diameter of a human hair, they bypass the nasal cilia and upper respiratory tract, penetrating deep into the alveoli of the lungs and directly entering the bloodstream.
Health Breakpoints (24-Hour & Hourly Concentration)
| Category | PM2.5 Range (µg/m³) | AQI Equivalent | Health Impact & Protective Action |
|---|---|---|---|
| Good | 0.0 – 12.0 | 0 – 50 | Air quality is satisfactory. Normal outdoor recreation. |
| Moderate | 12.1 – 35.4 | 51 – 100 | Sensitive individuals (asthma, COPD, cardiovascular) may notice mild irritation. |
| Unhealthy (Sensitive) | 35.5 – 55.4 | 101 – 150 | Children, seniors, and pregnant individuals should reduce strenuous outdoor exertion. |
| Unhealthy | 55.5 – 150.4 | 151 – 200 | Everyone begins to experience eye irritation and throat soreness. Limit time outdoors. |
| Very Unhealthy | 150.5 – 250.4 | 201 – 300 | Health alert: serious risk of respiratory symptoms. Avoid physical exertion outdoors; run HEPA filtration. |
| Hazardous | 250.5+ | 301 – 500+ | Emergency health warning. Remain indoors with air cleaners operating. Wear well-fitted N95/KN95 if outside. |
Optical Laser Telemetry
Fire Aware sensor nodes utilize dual-channel laser scattering optical particle counters (OPCs). A semiconductor laser illuminates the sample chamber, measuring light scatter angle and intensity to calculate particle count and aerodynamic mass in real time.
Indoor Clean Air Sheltering
During heavy smoke incursions, keep doors and windows closed, switch HVAC to recirculate, and operate certified HEPA air cleaners or low-cost Corsi-Rosenthal box fan filters to maintain indoor PM2.5 below 10 µg/m³.