Comprehensive simulation of particulate matter concentration in households

Description

Background
With most people in affluent countries spending most time at home, and particulate matter present at relatively high concentrations in homes (e.g. 20 ug m-3 PM2.5 mean across 300 Bradford homes), the mass concentration of particulate matter in households has potentially significant implications for health. An accurate simulator of household particulate matter would enable estimation of the associated exposure and health burden across household types and occupants.

Objectives
Testing the accuracy of a computer simulator of household particulate matter through comparison with observations from real households.

Methods
-An open-source computer model was developed that integrates outdoor air composition, emission rates of indoor activities and indoor activity diaries with gas-phase photochemistry and dynamic gas-particle and gas-surface partitioning.
-Particulate matter mass concentration was observed in real, inhabited UK homes, with occupant recording of indoor activity.
-Simulated mass of particulate matter per household was compared against observed to quantify accuracy.

Results
Simulated particulate matter was typically within 20 % of observed mass, allowing for accurate distinction between homes of relatively high particulate matter concentrations and those of lower concentrations. An apportionment method identified the key sources and sinks per household. Given that the disagreement between observations and the computer model is small compared to the variation in particulate matter concentrations between households, application of simulator estimates to exposure assessment is now suitable.

Conclusion
Provided with indoor activity timing, the simulator achieves sufficient accuracy to identify households with relatively high levels of particulate matter.

Period	11 Nov 2025
Event title	2025 UKHSA Annual Outdoor and Indoor Air Pollution Research Review Meeting
Event type	Conference
Location	Newcastle upon Tyne, United KingdomShow on map
Degree of Recognition	National