PM2.5 and PM10 are the primary dust parameters regulated on construction sites. PM10 (particles up to 10 micrometers) is the traditional regulatory focus. PM2.5 (particles up to 2.5 micrometers) increasingly receives regulatory attention because it’s more harmful to human health—PM2.5 particles penetrate deep into lungs and bloodstream, causing respiratory and cardiovascular effects.
The current UK annual PM2.5 limit is 20 µg/m³ under The Air Quality Standards Regulations 2010. England has additionally set a stricter target of 10 µg/m³ to be met by 2040. Construction sites often exceed both limits without comprehensive dust management. Understanding PM measurement and effective control strategies is essential for regulatory compliance and worker health protection.
Understanding PM10 vs PM2.5
PM10 (Coarse Particulates): Particles up to 10 micrometers. Includes dust from crushing, grinding, excavation, and demolition. PM10 largely deposits in upper respiratory tract—your nose catches much of it before it reaches lungs. PM10 is visible—this is the dust you see in construction clouds.
PM2.5 (Fine Particulates): Particles up to 2.5 micrometers. Includes combustion products, secondary organic aerosols, and smallest dust particles. PM2.5 bypasses upper respiratory defences and deposits deep in lungs, causing inflammatory responses and cardiovascular effects. PM2.5 is often invisible—you can’t see what’s most harmful.
A typical construction site crushing operation generates high PM10 (visible dust cloud) and high PM2.5 (invisible fine particles). Water suppression is effective at controlling PM10 (water droplets capture coarse particles). Water suppression is less effective at controlling PM2.5 (smallest particles are harder to capture).
Measurement and Regulatory Compliance
PM monitoring standards specify measurement methodology. PM10 and PM2.5 must be measured with certified equipment at specified distances from sources. Results are compared to regulatory limits. Exceedances trigger enforcement action.
The key regulatory distinction: a single exceedance of limits is not automatically a violation. Standards allow some number of exceedances annually (35 for PM10). Violation occurs when exceedances exceed the allowable number. This means sites don’t need to prevent all PM spikes—they need to prevent excessive spikes.
However, regulators increasingly focus on PM2.5 in addition to PM10. Many air quality compliance challenges involve PM10 compliance but PM2.5 exceedances. Understanding both parameters is essential.
Dust Control Effectiveness for PM10 vs PM2.5
Water Suppression: Highly effective for PM10 (up to 70-80% reduction through coarse particle capture). Moderately effective for PM2.5 (30-50% reduction through agglomeration of fine particles). Water suppression is insufficient as sole PM2.5 control.
Chemical Suppressants: More effective for PM2.5 than water alone. Cationic polymers can bind and agglomerate fine particles more effectively than water alone. Effectiveness depends on suppressant type and soil characteristics.
Enclosure and Local Extraction: Most effective for both PM10 and PM2.5 (80-95% reduction possible). Dust is captured at source before dispersal. Requires capital investment in equipment. Most effective for crushers, grinding, and other high-dust equipment.
Operational Changes: Equipment selection and scheduling can reduce PM generation. Wet cutting produces less dust than dry cutting. Crushing in enclosed equipment produces less ambient dust than uncovered crushing. Scheduling high-dust activities during favourable wind conditions reduces impacts.
Practical PM Monitoring and Control Implementation
Baseline PM Assessment: Measure current PM10 and PM2.5 under typical operations. Identify which activities generate highest PM. Identify which locations are highest-impact.
Equipment Selection: Optical sensors for real-time PM10 and PM2.5 monitoring. Gravimetric or passive sampling for legal compliance documentation.
Source-Specific Control Design: Don’t use generic suppression everywhere. Identify highest-PM sources and deploy targeted controls (enclosure, local extraction, wet methods). Use standard suppression for lower-impact areas.
Real-Time Adjustment: Monitor PM trends. If spikes occur, identify the source and adjust suppression. If PM remains low, reduce suppression intensity where safe, saving water and cost.
FAQ: PM2.5 and PM10 Monitoring
Q: What’s the difference between PM2.5 and PM10 regulation?
A: PM10 has 24-hour limits (50 µg/m³ max, 35 exceedances allowed annually). PM2.5 has annual limits (20 µg/m³). PM10 is visible dust. PM2.5 is health-damaging fine particles. Both must be controlled.
Q: Is water suppression sufficient for PM2.5 control?
A: Water suppression alone provides 30-50% PM2.5 reduction. For comprehensive PM2.5 control, combine suppression with enclosure, local extraction, or operational changes to limit health impacts. Multi-method approach provides best results.
Next Steps
PM2.5 and PM10 control on construction requires understanding both particle types and deploying appropriate control strategies for each. Real-time monitoring with optical sensors and multi-method suppression provides both compliance evidence and worker health protection.
If your construction project needs PM monitoring and control strategy, contact EMSOL to discuss PM2.5 and PM10 monitoring and control approaches appropriate for your specific sources.