Exhaled CO2 and aerosol dispersion on a cruise ship: Airflow and infection risk insights

Sarkawt Hama; Prashant Kumar; Ho Yin Wickson Cheung; Ana Paula Mendes Emygdio; John Ewer; Zhaozhi Wang; Edwin R. Galea; Angus Grandison; Fuchen Jia; Niko Siilin; Pierfrancesco Lepore

doi:10.1016/j.scitotenv.2025.181112

Exhaled CO₂ and aerosol dispersion on a cruise ship: Airflow and infection risk insights

Sarkawt Hama
, Prashant Kumar^*
, Ho Yin Wickson Cheung
, Ana Paula Mendes Emygdio
, John Ewer
, Zhaozhi Wang
, Edwin R. Galea
, Angus Grandison
, Fuchen Jia
, Niko Siilin
, Pierfrancesco Lepore
,

^*Corresponding author for this work

BA4902 Clean air solutions

Research output: Contribution to journal › Article › Scientific › peer-review

Abstract

Understanding airborne pathogen transmission in cruise ship environments remains a critical challenge due to the confined nature of indoor spaces, high occupancy, and limited access for real-world experimentation. This study addresses the gap in empirical data on particulate matter and CO₂ dynamics aboard operational cruise ships, providing a high-resolution dataset that can be used for the validation of Computational Fluid Dynamics (CFD) models and informing infection probability risk assessments. An experimental trial was designed for two mechanically ventilated cruise ship rooms (R01, R02), instrumented at ten locations under eight ventilation scenarios: R01 with 100 % (S1a) and 50 % (S1b) design flow rates; R02 with 100 % (S2a), 50 % (S2b) and 10 % (S2c) design flow rates; R01 with high aerosol rate and 50 % flow rate (S3); and R01 with an air purifier at maximum (S4a, 1300 m³ h⁻¹) and minimum (S4b, 422 m³ h⁻¹) clean air delivery rate (CADR). A live UK-EU cruise hosted the experimental trial. Particulate matter and CO₂ concentration, temperature and relative humidity were collected using portable sensors to build a unique dataset to validate subsequent computational modelling of aerosol dispersion, infection probability and transmission prevention, mitigation and management (PMM) approaches in arbitrary passenger ship spaces. As expected, PM and CO₂ were markedly reduced under 100 % design flow ventilation compared with 50 %. Maximum PM_2.5 reductions were 84 % during background, 29 % in build-up, and 72 % in decay experimental phases. An air purifier further reduced particulate matter, with peak PM reductions of 57 % (PM₁₀), 48 % (PM_2.5), and 45 % (PM₁). These findings offer practical guidance for optimising air quality management strategies in cruise ships and other high-occupancy spaces, besides providing a crucial high-resolution dataset for validating numerical modelling. Moreover, this study provides valuable insights into mechanically ventilated shipboard airflow behaviour.

Original language	English
Article number	181112
Journal	Science of the Total Environment
Volume	1010
DOIs	https://doi.org/10.1016/j.scitotenv.2025.181112
Publication status	Published - 1 Jan 2026
MoE publication type	A1 Journal article-refereed

Funding

HEALTHY SAILING project has received funding from the European Union's Horizon Europe Framework Programme (HORIZON) under Grant Agreement number 101069764. Funded by the European Union. Views and opinions expressed are, however, those of the author(s) only and do not necessarily reflect those of the European Union or the European Climate, Infrastructure and Environment Executive Agency (CINEA) or the cruise company. Neither the European Union nor the granting authority can be held responsible for them. This work was funded by UK Research and Innovation (UKRI) under the UK Government's Horizon Europe funding guarantee [grant numbers 10040786 and 10040720]. This work has received funding from the Swiss State Secretariat for Education, Research and Innovation (SERI). We also thank the MedicAir for their kind loan of the Air Purification unit that was used in a number of experimental trials to facilitate our understanding of possible mitigations.

Keywords

Aerosol dispersion
Airborne transmission
CO
Large cruise ship
Ventilation

Access to Document

10.1016/j.scitotenv.2025.181112

Cite this

@article{b15e9a65d8bf442cb71328550fa1d30d,

title = "Exhaled CO2 and aerosol dispersion on a cruise ship: Airflow and infection risk insights",

abstract = "Understanding airborne pathogen transmission in cruise ship environments remains a critical challenge due to the confined nature of indoor spaces, high occupancy, and limited access for real-world experimentation. This study addresses the gap in empirical data on particulate matter and CO2 dynamics aboard operational cruise ships, providing a high-resolution dataset that can be used for the validation of Computational Fluid Dynamics (CFD) models and informing infection probability risk assessments. An experimental trial was designed for two mechanically ventilated cruise ship rooms (R01, R02), instrumented at ten locations under eight ventilation scenarios: R01 with 100 \% (S1a) and 50 \% (S1b) design flow rates; R02 with 100 \% (S2a), 50 \% (S2b) and 10 \% (S2c) design flow rates; R01 with high aerosol rate and 50 \% flow rate (S3); and R01 with an air purifier at maximum (S4a, 1300 m3 h−1) and minimum (S4b, 422 m3 h−1) clean air delivery rate (CADR). A live UK-EU cruise hosted the experimental trial. Particulate matter and CO2 concentration, temperature and relative humidity were collected using portable sensors to build a unique dataset to validate subsequent computational modelling of aerosol dispersion, infection probability and transmission prevention, mitigation and management (PMM) approaches in arbitrary passenger ship spaces. As expected, PM and CO2 were markedly reduced under 100 \% design flow ventilation compared with 50 \%. Maximum PM2.5 reductions were 84 \% during background, 29 \% in build-up, and 72 \% in decay experimental phases. An air purifier further reduced particulate matter, with peak PM reductions of 57 \% (PM10), 48 \% (PM2.5), and 45 \% (PM1). These findings offer practical guidance for optimising air quality management strategies in cruise ships and other high-occupancy spaces, besides providing a crucial high-resolution dataset for validating numerical modelling. Moreover, this study provides valuable insights into mechanically ventilated shipboard airflow behaviour.",

keywords = "Aerosol dispersion, Airborne transmission, CO, Large cruise ship, Ventilation",

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AU - Hama, Sarkawt

AU - Kumar, Prashant

AU - Cheung, Ho Yin Wickson

AU - Emygdio, Ana Paula Mendes

AU - Ewer, John

AU - Wang, Zhaozhi

AU - Galea, Edwin R.

AU - Grandison, Angus

AU - Jia, Fuchen

AU - Siilin, Niko

AU - Lepore, Pierfrancesco

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N2 - Understanding airborne pathogen transmission in cruise ship environments remains a critical challenge due to the confined nature of indoor spaces, high occupancy, and limited access for real-world experimentation. This study addresses the gap in empirical data on particulate matter and CO2 dynamics aboard operational cruise ships, providing a high-resolution dataset that can be used for the validation of Computational Fluid Dynamics (CFD) models and informing infection probability risk assessments. An experimental trial was designed for two mechanically ventilated cruise ship rooms (R01, R02), instrumented at ten locations under eight ventilation scenarios: R01 with 100 % (S1a) and 50 % (S1b) design flow rates; R02 with 100 % (S2a), 50 % (S2b) and 10 % (S2c) design flow rates; R01 with high aerosol rate and 50 % flow rate (S3); and R01 with an air purifier at maximum (S4a, 1300 m3 h−1) and minimum (S4b, 422 m3 h−1) clean air delivery rate (CADR). A live UK-EU cruise hosted the experimental trial. Particulate matter and CO2 concentration, temperature and relative humidity were collected using portable sensors to build a unique dataset to validate subsequent computational modelling of aerosol dispersion, infection probability and transmission prevention, mitigation and management (PMM) approaches in arbitrary passenger ship spaces. As expected, PM and CO2 were markedly reduced under 100 % design flow ventilation compared with 50 %. Maximum PM2.5 reductions were 84 % during background, 29 % in build-up, and 72 % in decay experimental phases. An air purifier further reduced particulate matter, with peak PM reductions of 57 % (PM10), 48 % (PM2.5), and 45 % (PM1). These findings offer practical guidance for optimising air quality management strategies in cruise ships and other high-occupancy spaces, besides providing a crucial high-resolution dataset for validating numerical modelling. Moreover, this study provides valuable insights into mechanically ventilated shipboard airflow behaviour.

AB - Understanding airborne pathogen transmission in cruise ship environments remains a critical challenge due to the confined nature of indoor spaces, high occupancy, and limited access for real-world experimentation. This study addresses the gap in empirical data on particulate matter and CO2 dynamics aboard operational cruise ships, providing a high-resolution dataset that can be used for the validation of Computational Fluid Dynamics (CFD) models and informing infection probability risk assessments. An experimental trial was designed for two mechanically ventilated cruise ship rooms (R01, R02), instrumented at ten locations under eight ventilation scenarios: R01 with 100 % (S1a) and 50 % (S1b) design flow rates; R02 with 100 % (S2a), 50 % (S2b) and 10 % (S2c) design flow rates; R01 with high aerosol rate and 50 % flow rate (S3); and R01 with an air purifier at maximum (S4a, 1300 m3 h−1) and minimum (S4b, 422 m3 h−1) clean air delivery rate (CADR). A live UK-EU cruise hosted the experimental trial. Particulate matter and CO2 concentration, temperature and relative humidity were collected using portable sensors to build a unique dataset to validate subsequent computational modelling of aerosol dispersion, infection probability and transmission prevention, mitigation and management (PMM) approaches in arbitrary passenger ship spaces. As expected, PM and CO2 were markedly reduced under 100 % design flow ventilation compared with 50 %. Maximum PM2.5 reductions were 84 % during background, 29 % in build-up, and 72 % in decay experimental phases. An air purifier further reduced particulate matter, with peak PM reductions of 57 % (PM10), 48 % (PM2.5), and 45 % (PM1). These findings offer practical guidance for optimising air quality management strategies in cruise ships and other high-occupancy spaces, besides providing a crucial high-resolution dataset for validating numerical modelling. Moreover, this study provides valuable insights into mechanically ventilated shipboard airflow behaviour.

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KW - Airborne transmission

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KW - Ventilation

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ER -

Exhaled CO₂ and aerosol dispersion on a cruise ship: Airflow and infection risk insights

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HEALTHY SAILING: Prevention, mitigation, management of infectious diseases on cruise ships and passenger ferries

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Exhaled CO2 and aerosol dispersion on a cruise ship: Airflow and infection risk insights

Abstract

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Projects

HEALTHY SAILING: Prevention, mitigation, management of infectious diseases on cruise ships and passenger ferries

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Exhaled CO₂ and aerosol dispersion on a cruise ship: Airflow and infection risk insights