PM2.5 and PM10 Monitoring on Construction: A Complete Guide
You’ve heard about PM2.5 and PM10, seen them mentioned in air quality reports, and know construction sites must monitor them. But what exactly are these particles? Why do they matter separately? And how should you be measuring them on your site?
Understanding the difference between PM2.5 and PM10 is critical to managing construction air quality effectively. They have different sources, different health impacts, different regulatory limits, and different control requirements. Treating them as a single “dust problem” will leave you missing risks that regulators and environmental agencies specifically care about.
Here’s what you need to know about particulate monitoring and why source identification changes how you manage both.
What PM2.5 and PM10 Are, and Why Both Matter
PM stands for particulate matter. The number indicates the particle size in microns (millionths of a metre). PM10 includes all particles 10 microns and smaller. PM2.5 includes the finer subset—particles 2.5 microns and smaller. Think of it like a net: PM10 catches everything small enough to matter for air quality. PM2.5 catches the smallest, most dangerous particles within that net.
Size matters because it determines where particles lodge in the human respiratory system. PM10 particles are large enough that your nose and upper airways filter some of them. PM2.5 particles are so small they bypass your nose and travel deep into your lungs, where they deposit in the alveoli (air sacs) and cause direct damage. Understanding health impacts of particulate matter helps clarify why PM2.5 is considered the more serious health hazard.
UK Environmental Quality Standards (EQS) set air quality compliance limits: PM10 at 50 µg/m³ as a daily mean (not to be exceeded more than 35 days per year) and 40 µg/m³ as an annual mean. PM2.5 at 25 µg/m³ as an annual mean. Construction sites must avoid breaching these limits, particularly at sensitive receptors (homes, schools, hospitals).
Construction activities generate both. Demolition, excavation, and hauling generate larger particles (PM10 range). Managing air quality during demolition critical compliance steps addresses the unique sources that create both PM10 and finer particles. Crushing, grinding, and traffic on unpaved roads generate finer particles (PM2.5 range). Dust suppression methods affect them differently—water controls larger particles effectively but is less effective on fine particles that stay airborne longer.
Why Particle-Only Monitoring Misses Critical Insights
Many construction sites monitor PM10 and PM2.5 levels at property boundaries—measuring compliance with EQS limits. This approach answers one question: “Are we within regulatory limits?” But it doesn’t answer the operational questions that actually prevent problems:
Which activity generated the PM2.5? Crushing creates different particulate signatures than traffic. Demolition differs from excavation. Without source identification, you can’t target controls effectively. You might increase water suppression across the entire site when the actual problem is uncontrolled crushing in one area. How to identify dust sources on your construction site provides the foundational approach to this critical analysis.
Where is the PM2.5 coming from spatially? A single boundary monitor shows you a reading but not the source direction or distance. Is the spike from your site or from wind-blown dust from neighbouring activity? You can’t defend your compliance record without knowing whether exceedances originate from your operations or external sources.
How quickly can you respond? By the time PM2.5 readings spike at a boundary sensor, fine particles have already travelled significant distances. They originated elsewhere on your site minutes earlier. Real-time dust monitoring systems which one works best enables rapid response before particles reach sensitive receptors. Without them, you can only document that exceedances occurred.
Particle monitoring alone tells you “what happened”—levels exceeded limits. Source identification tells you “what caused it”—activity X in location Y generated it—enabling you to prevent it.
How Source Identification Transforms Particulate Management
Integrated approach adds source attribution to particulate monitoring. You measure PM2.5 and PM10 levels at multiple site locations with real-time sensors, positioned to detect spatial distribution patterns. Video monitoring and AI activity detection identify which equipment is operating. Statistical correlation links measured spikes to specific activities.
The system learns that your crusher generates PM2.5 spikes within 8-12 minutes downwind of operation. Your excavator generates larger particles (PM10) but less fine dust. Your haul road generates mixed particulates depending on traffic volume and surface condition.
When a PM2.5 spike occurs at a boundary sensor, the system immediately identifies which source activity is most likely responsible, based on historical correlation. It shows video from that timeframe. Site managers can deploy targeted suppression (enclosing the crusher, wetting the haul road, or suspending excavation) instead of guessing.
This operational intelligence reduces both particles: coarser PM10 by targeting the primary source, and finer PM2.5 by understanding which activities generate respirable dust and controlling them more aggressively. For broader compliance context, what happens if you dont comply with air quality requirements on site illustrates the escalating regulatory consequences that effective particulate management prevents.