Challenges In Modern: 5 Essential Tips

Abstract

Background: Analyzing Particulate Matter Monitoring (PM2.5/PM10) Challenges in Modern Buildings is increasingly relevant in dense urban centres such as Dubai, where sealed, mechanically ventilated offices rely on HVAC systems to control indoor air quality. While PM2.5 and PM10 are established risk factors for respiratory and cardiovascular disease, translating outdoor metrics and standards into reliable indoor measurements remains technically challenging due to spatial variability, transient indoor sources, and complex airflow patterns.

Case Presentation: This case study describes a 28‑storey, mechanically ventilated office tower in Dubai Internet City, housing approximately 1,100 employees, which exhibited inconsistent PM2.5/PM10 readings across different floors despite similar occupancy and HVAC setpoints. Complaints included perceived “stuffy” air, eye irritation, and visible dust on workstations in selected zones. The facility team requested a scientific investigation to characterise particulate profiles and identify monitoring limitations. This relates directly to Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings.

Methods/Assessment: A four‑week monitoring campaign was implemented across three representative floors (low, mid, high level). Direct‑reading optical particle counters (OPCs) measured PM2.5 and PM10 at 1‑minute resolution in open‑plan areas, meeting rooms, and near air‑handling unit (AHU) supply diffusers. Outdoor reference measurements were recorded on the roof. HVAC operating data (supply air volume, filter types, and fan schedules) were also captured. Data were analysed for diurnal profiles, spatial gradients, and deviations relative to WHO and local guideline values. When considering Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings, this becomes clear.

Results: Median indoor PM2.5 ranged from 12 to 28 µg/m³ between floors, versus a median outdoor level of 42 µg/m³. However, episodic peaks between 65 and 120 µg/m³ were observed in certain zones during morning and late evening cleaning, and during intermittent construction activities on adjacent floors. Sensor location and proximity to supply diffusers significantly affected readings, with up to a 40% difference over distances of less than 10 m. Continuous monitoring adjacent to return grilles underestimated occupant breathing‑zone exposure during peak events. The importance of Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings is evident here.

Conclusion: This case highlights that PM2.5/PM10 monitoring in modern buildings can yield misleading conclusions if challenges around sensor placement, temporal coverage, HVAC operation, and indoor sources are not explicitly addressed. Robust monitoring strategies must integrate building science, HVAC data, and multiple sampling locations to accurately characterise occupant exposure and to support evidence‑based environmental management. Understanding Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings helps with this aspect.

Keywords: Analyzing Particulate Matter Monitoring (PM2.5/PM10) Challenges in Modern Buildings, indoor air quality, HVAC, office buildings, Dubai, optical particle counters

Introduction

Particulate matter with aerodynamic diameters below 2.5 µm (PM2.5) and 10 µm (PM10) is associated with increased morbidity and mortality due to cardiovascular, respiratory, and systemic inflammatory effects. International bodies such as the World Health Organization provide guideline values, for example annual mean PM2.5 of 5 µg/m³ and 24‑hour mean of 15 µg/m³, and 24‑hour PM10 of 45 µg/m³. However, these guidelines are largely derived from ambient outdoor monitoring networks, whereas most people in regions like the United Arab Emirates spend more than 85% of their time indoors in air‑conditioned spaces. Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings factors into this consideration.

Modern office buildings in Dubai, Abu Dhabi, and other Gulf cities are typically sealed envelopes with centralised HVAC systems providing mechanical ventilation, cooling, and filtration. In theory, this configuration can reduce indoor particulate levels relative to outdoors through filtration and pressurisation. In practice, however, indoor PM2.5 and PM10 levels are influenced by a complex interaction of outdoor infiltration, indoor sources (occupants, printers, cooking, cleaning, nearby construction), HVAC filtration efficiency, airflow distribution, and maintenance practices. These factors introduce challenges for accurately monitoring and interpreting PM in such environments. This relates directly to Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings.

The present case is unique because the building in question already maintained what appeared to be adequate HVAC filtration and nominal compliance with ventilation standards, yet exhibited inconsistent PM readings and occupant complaints localised to specific zones. The case therefore provides an opportunity to examine Analyzing Particulate Matter Monitoring (PM2.5/PM10) Challenges in Modern Buildings from a building‑science perspective in a real Dubai context. Rather than treating monitoring as a simple exercise in placing a single sensor on each floor, the investigation explicitly considered sensor placement, temporal resolution, HVAC operation, and the impact of intermittent sources.

The aim of this case study is to describe the monitoring campaign implemented in the building, report the quantitative PM2.5/PM10 results, and highlight the practical and scientific challenges encountered in accurately characterising indoor particulate exposure in a high‑rise, mechanically ventilated office in Dubai. The case illustrates how improper monitoring strategies may lead to underestimation or mischaracterisation of risk, and proposes methodological considerations for practitioners working in similar environments across the UAE. When considering Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings, this becomes clear.

Case Presentation

Subject/Case Description

The subject building is a 28‑storey commercial office tower located in Dubai Internet City. The structure was completed in 2017 and has a gross floor area of approximately 42,000 m². It is fully mechanically ventilated and cooled via central chilled water systems feeding multiple air‑handling units (AHUs) per floor. Filtration at AHUs consisted of prefilters (G4) and fine filters (F7 equivalents), typical for Class A office space in the region. The façade is predominantly double‑glazed curtain wall with relatively low infiltration rates under normal pressure differentials. The importance of Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings is evident here.

The case study focused on three representative tenant floors:

• Floor 5: Lower‑level technology company, open‑plan offices plus server room.
• Floor 14: Mid‑level co‑working space with high occupant churn and frequent small events.
• Floor 23: Upper‑level corporate headquarters floor with executive offices and boardrooms.

Across the building, occupancy during weekdays averaged around 1,100 persons between 08:00 and 19:00, with reduced presence thereafter. Cleaning staff operated from 19:30 to 23:00. Outdoor air was supplied according to design at approximately 10 L/s per person, with recirculation and economiser strategies disabled due to high outdoor temperatures for most of the year. Understanding Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings helps with this aspect.

Relevant History/Context

During the previous 12 months, the facility management team had received intermittent complaints primarily from occupants on Floors 14 and 23 regarding “stuffy” air, transient eye irritation, and visible dust accumulation on workstation surfaces within a day or two of cleaning. A previous consultant had installed a single low‑cost PM sensor in the lift lobby of each floor for two weeks and concluded that “PM levels are generally acceptable,” as average PM2.5 remained below 25 µg/m³, without detailed analysis of peaks or spatial variability. Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings factors into this consideration.

Parallel to these complaints, the building had experienced intermittent interior fit‑out works on various floors, including drilling, minor partition modifications, and furniture replacements. These activities varied in schedule and were not always announced to the central facility team. Housekeeping used dry sweeping followed by mopping in corridors and some office areas, and a combination of vacuuming and dusting in others, with no specific guidance on dust containment. This relates directly to Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings.

Problem/Symptoms

The primary issues prompting detailed investigation were:

• Perceived poor air quality and visual dust accumulation in specific zones despite apparently adequate HVAC operation and filter maintenance.
• Inconsistent PM2.5/PM10 readings from portable spot measurements performed by the facility team at different times and locations.
• Concern that monitoring data collected only at lift lobbies might not represent actual occupant exposure, particularly in densely occupied open‑plan areas and meeting rooms.

The building owner, aiming to position the property for WELL Building Standard certification in the future, requested a rigorous assessment that would not only measure PM but also evaluate the technical challenges and limitations of the current monitoring approach. When considering Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings, this becomes clear.

Timeline

The monitoring campaign and associated events occurred over approximately eight weeks, including planning, baseline review, monitoring, and feedback implementation, as summarised in Table 1. The importance of Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings is evident here.

Table 1: Chronological Timeline of Events

Date/Period	Event	Key Observation	Action Taken
Week −4	Initial complaints escalate on Floors 14 and 23	Reports of stuffy air and dust on desks	Facility team performs ad hoc spot PM checks
Week −2	Consultation with indoor environmental specialist	Existing data limited to lobby sensors and sporadic readings	Decision to implement structured PM2.5/PM10 study
Week 0	Site survey and HVAC documentation review	Filters maintained on schedule, no obvious faults	Monitoring plan and sensor locations defined
Week 1	Deployment of PM sensors and outdoor reference unit	Baseline readings collected with minimal disturbances	Begin 4‑week continuous monitoring
Week 2	Unexpected evening fit‑out work on Floor 15	Short‑term PM spikes observed on Floor 14 sensors	Event logged and correlated with data
Week 3	Deep cleaning cycle on Floor 23	Substantial increase in PM10 during sweeping/moving furniture	Adjust cleaning schedule and methods for test zones
Week 4	Monitoring period ends	Data completeness > 95%, clear diurnal patterns and peaks	Data analysis and reporting
Week 6	Feedback session with facility and tenants	Discussion of findings and monitoring limitations	Recommendations for revised PM monitoring strategy

Understanding Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings helps with this aspect.

Methods / Assessment

The assessment was designed to be reproducible and to explicitly address Analyzing Particulate Matter Monitoring (PM2.5/PM10) Challenges in Modern Buildings, particularly the influence of spatial gradients, HVAC airflow patterns, and intermittent indoor sources.

Sampling Strategy

Continuous monitoring was conducted for 28 consecutive days on Floors 5, 14, and 23 and on the building roof (outdoor reference). On each selected floor, three fixed indoor monitoring points were deployed: Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings factors into this consideration.

• Open‑plan zone approximately at occupant breathing height (1.2 m above floor) in a high‑occupancy area.
• Enclosed meeting room with typical occupancy of 6–10 persons.
• Near the main supply diffuser cluster in the open‑plan area, 2.5 m above floor, to characterise supply air particle levels.

Additionally, a mobile handheld meter was used twice weekly to perform short spot checks at other locations (reception, corridors, print areas) to identify unanticipated hotspots. The roof‑top outdoor station was positioned away from direct exhaust plumes and at least 5 m from the edge to minimise wind artefacts. This relates directly to Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings.

Instrumentation

All fixed monitoring points used calibrated optical particle counters (OPCs) capable of reporting PM1, PM2.5, and PM10 mass concentrations, with 1‑minute logging intervals. For the purposes of this case study, emphasis is on PM2.5 and PM10. The instruments used manufacturer‑specified gravimetric calibration factors aligned with ISO 21501‑4. Each unit was factory‑calibrated within the previous 12 months and cross‑checked against a reference unit on site before deployment. When considering Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings, this becomes clear.

The handheld meter used for spot checks employed similar OPC technology but stored only averaged values over 30‑second intervals. Although less precise, it served as a qualitative screening tool. The importance of Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings is evident here.

Standards and Reference Values

Interpretation of PM levels considered WHO Air Quality Guidelines (24‑hour PM2.5 15 µg/m³, PM10 45 µg/m³), as well as commonly used office‑building design benchmarks that aim for indoor PM2.5 at 50% or less of simultaneous outdoor levels where feasible. No binding federal UAE indoor PM guidelines existed at the time of the study, so international references were adopted for comparative assessment. Understanding Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings helps with this aspect.

Data Analysis

Data were downloaded in CSV format and processed using statistical software. Steps included quality control (removal of sensor warm‑up periods, obvious outliers due to instrument handling), computation of 1‑hour moving averages, and derivation of daily and weekly summary statistics (min, max, median, 95th percentile). Time‑aligned comparison between indoor and outdoor series was performed to determine infiltration patterns and filtration performance. Event logs (cleaning schedules, fit‑out works, HVAC schedule changes) were overlaid to attribute peaks where possible. Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings factors into this consideration.

Table 2: Assessment Methods and Standards

Parameter	Method/Instrument	Standard Reference	Frequency
PM2.5 mass concentration	Fixed OPC, 1‑minute logging	ISO 21501‑4 calibration; WHO AQG for interpretation	Continuous, 28 days
PM10 mass concentration	Fixed OPC, 1‑minute logging	ISO 21501‑4; WHO AQG 24‑h PM10	Continuous, 28 days
Outdoor PM2.5/PM10	Roof‑top OPC reference unit	Same as indoor; used for ratio comparisons	Continuous, 28 days
Spot PM screening	Handheld OPC, 30‑s averages	Manufacturer calibration	Twice weekly, various locations
Occupancy patterns	Access control data; observation	Internal facility records	Weekdays, 08:00–19:00
HVAC operation	BMS trend logs (fan status, filter DP)	Manufacturer specifications	Continuous, 28 days

This relates directly to Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings.

Results / Findings

Results are presented first as summary statistics for each monitoring location, followed by visual comparisons between indoor and outdoor levels, and observations regarding spatial and temporal variability. Interpretation is reserved for the Discussion section. When considering Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings, this becomes clear.

Summary of Key Measurements

Table 3 summarises the primary PM2.5 and PM10 findings as 24‑hour median values and 95th percentile values over the 28‑day period for each fixed monitoring location and the outdoor reference. The importance of Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings is evident here.

Table 3: Summary of Key Findings

Measurement	Method	Result	Reference Range	Status
Outdoor PM2.5 (24‑h median)	Roof OPC	42 µg/m³	WHO 24‑h guideline 15 µg/m³	Exceeded
Outdoor PM10 (24‑h median)	Roof OPC	78 µg/m³	WHO 24‑h guideline 45 µg/m³	Exceeded
Floor 5, open‑plan PM2.5 (median)	Fixed OPC	18 µg/m³	Target < 50% of outdoor (21 µg/m³)	Within target
Floor 5, open‑plan PM2.5 (95th percentile)	Fixed OPC	52 µg/m³	WHO 24‑h guideline 15 µg/m³	Exceeded peaks
Floor 14, open‑plan PM2.5 (median)	Fixed OPC	24 µg/m³	Target < 50% of outdoor (21 µg/m³)	Above target
Floor 14, open‑plan PM2.5 (95th percentile)	Fixed OPC	68 µg/m³	WHO 24‑h guideline 15 µg/m³	Exceeded peaks
Floor 23, open‑plan PM2.5 (median)	Fixed OPC	21 µg/m³	Target < 50% of outdoor (21 µg/m³)	At target
Floor 23, open‑plan PM2.5 (95th percentile)	Fixed OPC	60 µg/m³	WHO 24‑h guideline 15 µg/m³	Exceeded peaks
Floor 14, meeting room PM10 (median)	Fixed OPC	34 µg/m³	WHO 24‑h guideline 45 µg/m³	Within guideline
Floor 14, meeting room PM10 (95th percentile)	Fixed OPC	92 µg/m³	WHO 24‑h guideline 45 µg/m³	Exceeded peaks
Floor 23, near supply diffuser PM2.5 (median)	Fixed OPC	14 µg/m³	Target < 50% of outdoor (21 µg/m³)	Within target
Floor 23, open‑plan vs supply PM2.5 difference	Fixed OPC	≈ 40% higher in open‑plan during peaks	No direct guideline	Significant gradient

Indoor vs Outdoor Comparison

Across the monitoring period, outdoor PM2.5 exhibited a median of 42 µg/m³, with daily medians ranging from 31 to 55 µg/m³. Outdoor PM10 medians ranged from 65 to 110 µg/m³, reflecting typical dust and traffic conditions in Dubai. Indoor medians were consistently lower than outdoor, confirming some degree of filtration and envelope protection. However, 95th percentile indoor values for PM2.5 frequently exceeded 60 µg/m³ in Floors 14 and 23, particularly during evenings. Understanding Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings helps with this aspect.

Temporal Patterns

Diurnal profiles showed characteristic patterns:

• Morning arrival period (08:00–10:00): Moderate PM2.5/PM10 peaks associated with door opening, elevator use, and occupant movement.
• Mid‑day (11:00–15:00): Relatively stable PM2.5 levels with small fluctuations corresponding to occupancy density in meeting rooms.
• Evening (19:30–22:30): Pronounced PM10 peaks, especially on Floors 14 and 23, coinciding with dry sweeping, vacuuming, and rearrangement of furniture during cleaning.
• Intermittent peaks on Floor 14 correlated with documented fit‑out activity one floor above, despite no direct works on Floor 14.

Spatial Variability

Direct comparison between the supply‑diffuser‑adjacent sensor and the open‑plan breathing‑zone sensor on Floor 23 revealed that while median PM2.5 at the supply location was 14 µg/m³, open‑plan median was 21 µg/m³ and 95th percentile events were approximately 40% higher in the open‑plan sensor. Spot checks conducted with the handheld meter showed even higher short‑term peaks (up to 120 µg/m³ PM2.5) near high‑traffic copier/printer areas that lacked fixed sensors. Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings factors into this consideration.

Data Visualisation: Relative Levels vs Guidelines

This relates directly to Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings.

Discussion

The results from this building illustrate several interrelated aspects of Analyzing Particulate Matter Monitoring (PM2.5/PM10) Challenges in Modern Buildings. Although the HVAC system provided measurable filtration, with indoor medians consistently below outdoor levels, episodic peaks and spatial gradients demonstrated that simplistic monitoring strategies can misrepresent actual occupant exposure.

Implications of Indoor vs Outdoor Ratios

Indoor median PM2.5 levels on Floor 5 and the supply‑air location of Floor 23 met the commonly cited design objective of maintaining indoor levels at or below 50% of outdoors. However, Floor 14’s median PM2.5 of 24 µg/m³ corresponded to approximately 57% of outdoor levels, suggesting higher indoor contributions or less effective dilution. This may be associated with the higher occupant churn, more frequent events, and more intensive use of printing and shared equipment. The finding emphasises that even within the same building envelope and central plant, floor‑level activities and layouts influence PM performance. When considering Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings, this becomes clear.

Temporal Resolution and Peak Exposure

While daily medians provide useful summary information, they conceal the fact that during certain periods, PM2.5 and PM10 concentrations substantially exceeded guideline values. Evening cleaning activities produced short‑term PM10 peaks up to 92 µg/m³ in meeting rooms, and PM2.5 peaks over 60 µg/m³ in open‑plan areas. If monitoring had been restricted only to working hours or to 24‑hour averages, these events might have been underestimated or overlooked entirely. For sensitive occupants or for building certifications that consider peak exposures, such omissions could be significant. The importance of Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings is evident here.

This aligns with broader literature recognising that indoor PM exposure is highly episodic, driven by discrete activities such as cooking, printing, or floor cleaning. In the UAE context, additional factors such as wind‑blown dust and regional pollution episodes can further elevate outdoor baselines, making indoor control more challenging. Understanding Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings helps with this aspect.

Sensor Placement and Spatial Variability

One of the most striking findings was the magnitude of spatial variability across relatively small distances. The sensor positioned near the supply diffuser consistently reported lower PM2.5 than the open‑plan sensor, particularly during occupancy peaks. This demonstrates that sampling only near supply points risks underestimating breathing‑zone exposure, as re‑suspended dust from floors, chairs, and surfaces accumulates and recirculates within the occupied zone before being captured by returns. Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings factors into this consideration.

Similarly, the prior consultant’s reliance on lobby‑mounted sensors likely biased results towards more stable, better ventilated zones that are not fully representative of dense open‑plan workstations or enclosed meeting rooms with variable occupancy. The handheld spot‑check measurements near printing areas, which revealed transient PM2.5 up to 120 µg/m³, further reinforce that unmonitored hotspots can exist in routine office environments. This relates directly to Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings.

Impact of Intermittent Sources and Adjacent Activities

The correlation between PM peaks on Floor 14 and fit‑out works on Floor 15 indicates vertical and horizontal transport of particulates through shafts, stairwells, and imperfectly sealed partition penetrations. Even when direct works do not occur on a monitored floor, adjacent floors can act as source zones. Monitoring that does not capture these interactions may incorrectly attribute peaks solely to within‑floor activities or, conversely, fail to recognise the role of building‑wide events. When considering Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings, this becomes clear.

Cleaning practices emerged as a significant source of both PM10 and PM2.5. Dry sweeping, movement of chairs, and dusting generated readily detectable peaks during evening hours. From a monitoring perspective, it means that classification of the building as “compliant” or “non‑compliant” with reference values depends critically on whether monitoring spans these periods and how results are aggregated. From a control perspective, substituting damp methods, HEPA‑filtered vacuums, and different scheduling could significantly reduce these peaks. The importance of Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings is evident here.

Instrumentation and Calibration Considerations

Optical particle counters provide high temporal resolution and relative patterns, but they infer mass concentrations from optical scattering, which can be affected by particle composition, shape, and humidity. In the Gulf climate, high humidity events or particles with different refractive indices (for example dust versus combustion particles) may introduce biases relative to gravimetric reference methods. In this case, all instruments were of the same type and calibration lineage, enabling internally consistent comparisons between locations, but absolute correspondence to gravimetric standards may still carry uncertainty.

Low‑cost sensors, if used, would compound these challenges, as their response to high dust environments and humidity can be markedly non‑linear. This underscores the importance of understanding instrument limitations when designing monitoring schemes and interpreting data for compliance or health risk assessments.

Comparison With Other Studies

Studies of indoor PM in urban residential and office buildings commonly report indoor PM2.5 levels lower than outdoors when filtration is present, but still with significant transient peaks linked to human activities. Research on typical urban homes has similarly shown that PM10 and PM2.5 peaks frequently exceed guideline thresholds during specific events even when daily averages appear acceptable. In office contexts, printers, cooking areas, and cleaning activities have been highlighted as contributors to episodic spikes. The present case aligns with this body of work and extends it to a high‑rise Dubai office scenario, where outdoor dust and high HVAC dependency add complexity.

Table 4: Comparison with Published Studies

Study	Sample Size	Key Finding	This Study
Urban residential PM2.5 review (various cities)	n > 100 dwellings	Indoor PM2.5 typically 50–80% of outdoor, episodic peaks during activities	Indoor medians 33–57% of outdoor; strong peaks during cleaning and fit‑out
Restaurant and lab kitchen IAQ case study	4 cooking sessions	High PM peaks during cooking despite relatively low background	High PM peaks during cleaning and construction despite filtered background
Office IAQ investigations in mechanically ventilated buildings	Multiple case reports	Sensor placement critically affects perceived IAQ; lobbies under‑represent work zones	Lobby/supply‑adjacent sensors under‑estimate open‑plan and hotspot exposure

Limitations

Several limitations should be acknowledged. First, mass concentrations were inferred from optical methods rather than gravimetric reference samplers. While this allowed high temporal resolution and comparative analysis across locations, absolute values may deviate from standard reference instruments, especially under varying humidity and particle composition. Second, monitoring was limited to three floors in a single building over four weeks, which may not capture seasonal variation, long‑term trends, or behaviours on other floors with different tenants or layouts. Third, chemical composition of particulates was not analysed, so differentiation between crustal dust, combustion particles, and indoor‑generated organic aerosols was not possible. This constrains risk assessment for specific health endpoints. Finally, occupant health outcomes were not systematically collected beyond complaint logs, limiting the ability to link exposures with symptoms in a quantitative manner. Despite these constraints, the data are sufficiently robust to illustrate key monitoring challenges and to inform practical recommendations.

Conclusion

This case study of a high‑rise office tower in Dubai demonstrates that Analyzing Particulate Matter Monitoring (PM2.5/PM10) Challenges in Modern Buildings requires more than simply deploying a small number of sensors and comparing averages to guideline values. The building’s HVAC system achieved partial filtration effectiveness, as evidenced by lower indoor medians relative to outdoors, yet significant short‑term peaks and spatial variability occurred due to cleaning, adjacent construction activities, and localised re‑suspension in occupant zones.

Key lessons include the critical influence of sensor placement, the necessity of capturing off‑hour events such as evening cleaning, and the importance of integrating event logs and HVAC operation data when interpreting PM measurements. Sampling only in lobbies or near supply diffusers risks underestimating exposure at workstations and in meeting rooms. Conversely, over‑reliance on short‑term spot checks can overemphasise transient events without contextualising them within daily or weekly patterns.

For practitioners and building owners in the UAE and similar climates, robust PM monitoring strategies should incorporate multiple breathing‑zone sensors per critical floor, continuous data collection across representative weeks, and deliberate coordination with facility and housekeeping operations. Future work could expand to multi‑building portfolios, incorporate chemical speciation, and evaluate the efficacy of specific interventions such as filter upgrades, pressurisation adjustments, and modified cleaning protocols. Ultimately, improving PM monitoring practice is essential for making indoor environmental decisions that genuinely protect occupant health and support credible certification efforts. Understanding Analyzing Particulate Matter Monitoring (pm2.5/pm10) Challenges In Modern Buildings is key to success in this area.