Broad particle monitoring in a school context
Particulate matter is one of the most contextually variable indoor pollutants. The same classroom can be moderately clean on a quiet morning and significantly more loaded after a busy lesson, a cleaning shift or a period of poor outdoor air. A broad monitoring approach acknowledges that variability and is designed to capture it rather than ignore it.
Combining PM2.5 and PM10 measurement, often with additional particle-count information, gives a fuller picture of both the size distribution of particles in the air and how it changes through the day. That combination tends to be more informative than either single fraction in isolation.
PM2.5 and PM10 together
PM2.5 and PM10 measure overlapping but different fractions of airborne particulate matter. Looking at them together identifies whether the dominant contribution is fine, combustion-related particles, coarser dust-type particles, or a mix. That distinction directly influences which mitigations are realistic — ventilation strategy and outdoor-air management point to one set of actions; cleaning, source control and dust management point to another.
If you need a focused brief on either fraction, see our PM2.5 monitoring or PM10 monitoring pages.
Particle-count trends and patterns
Where instrumentation supports it, particle counts in finer size bins add useful detail without changing the headline interpretation. The aim is not to chase the last particle but to identify reproducible patterns: which rooms behave differently from the rest, which time windows are problematic, which activities coincide with rises, and which periods are reassuringly stable.
Patterns that hold across multiple days are far more useful than spikes that appear once and never repeat. Reporting reflects that: prioritising consistent signals over outliers.
Room comparison
Comparing rooms is one of the most useful analytical steps available. A road-facing classroom against a courtyard-facing one, an upper-floor science room against a ground-floor primary room, a hall used at assembly against one used as a study space — these comparisons surface insight that single-room measurement cannot.
Where the same monitoring methodology is used across an estate, the same comparison can be done between buildings and between sites. That is particularly useful for multi-academy trusts and local authority estates teams.
Outdoor, occupancy and activity influence
Indoor particle concentrations almost always reflect a combination of outdoor air, occupancy and the activities going on in the room. Interpretation explicitly separates these influences as far as the data allows — comparing indoor and outdoor concentrations, lining up monitoring data against timetables and occupancy, and noting any known activities (cleaning, refurbishment, cooking, art and DT work) that fall within the monitoring period.
Reporting and recommendations
Outputs are designed for school leaders and estates teams rather than specialist audiences. Reports include a clear summary of what was measured and where, the data in plain language, an interpretation against relevant guidance (such as WHO 2021 air quality guidelines) and a prioritised list of operational and capital actions. Where longer-term monitoring would add value, the report says so and explains why.
Suitable schools and settings
- Single schools and multi-academy trusts
- Estates teams comparing buildings on the same basis
- Sites with mixed outdoor and indoor particle concerns
- Schools planning ventilation or refurbishment changes
Frequently asked questions
What does 'airborne particle monitoring' cover?+
It usually combines PM2.5 and PM10 measurement, sometimes with particle counts in additional size bins. The aim is a broader picture of how particulate matter behaves across rooms and across the day, rather than focusing on a single size fraction.
How is this different from PM2.5 or PM10 alone?+
Single-fraction monitoring answers a specific question (fine combustion-related particles or coarser dust). Combined monitoring is more useful when the question is broader — whether particulate matter is a meaningful issue across the school, where it concentrates and what is driving the pattern.
Can one reading tell us if there is a problem?+
Rarely. Particle concentrations vary by hour, day, season and activity. Useful conclusions almost always come from trends — across rooms, across days and against outdoor conditions — rather than a single point measurement.
How is source identification handled?+
By combining the monitoring data with site observation, occupancy patterns and known activities. The shape of the data — when concentrations rise, in which rooms, alongside what activity — usually narrows the source category quickly, even when a single source cannot be confirmed in isolation.
What outputs do schools get from this work?+
A written report covering rooms assessed, methodology, the data summarised in plain language, an interpretation against relevant guidance and a prioritised list of practical recommendations. Where appropriate, the report indicates which rooms would benefit from longer-term monitoring.
Ready to take a closer look at your school's air?
Tell us about your buildings and the rooms or year groups you're concerned about. A specialist will be in touch within one working day.