Experimental investigation of cross infection risk in indoor environments for different respiratory activities
Translated title
Eksperimentel undersøgelse af kryds kontaminering i indeklima for forskellige respiratoriske aktiviteter
Author
Madsen, Simon
Term
4. term
Publication year
2023
Submitted on
2023-06-09
Pages
125
Abstract
For at forstå, hvordan smitte spredes mellem mennesker, har vi brug for mål for, hvor meget udåndet luft fra en smitsom person når en modtagelig person. Det såkaldte susceptible exposure index (SEI) er et sådant mål. Tidligere studier har beregnet SEI for vejrtrækning i mange situationer, men få har undersøgt hoste, og direkte sammenligninger på tværs af respiratoriske aktiviteter er uklare. I dette studie måler vi eksponeringen ved vejrtrækning og hoste i et fuldskalaeksperiment. Vi brugte termiske manikiner til at efterligne personer og konstruerede en enhed, der kan reproducere en realistisk hoste; tests viste, at hosten stemte godt overens med den teoretiske profil. Eksponeringen blev beregnet ved hjælp af sporgasmålinger (en gas, der bruges til at spore luftstrømme). Vi fandt, at eksponeringen fra hoste kan være høj selv over store afstande. Fordi SEI fra forskellige aktiviteter ikke kan sammenlignes direkte, beregnede vi i stedet en vægtet eksponering for at muliggøre en mere retfærdig sammenligning.
To understand how infections spread between people, we need measures of how much exhaled air from an infectious person reaches a susceptible person. The susceptible exposure index (SEI) is one such metric. Prior studies have estimated SEI for breathing in many settings, but fewer have examined coughing, and direct comparisons across respiratory activities have been unclear. This study measures exposure during breathing and coughing in a full-scale experiment. We used thermal manikins to simulate people and built a device that produces a realistic cough; tests showed its output matched the theoretical cough profile well. We estimated exposure using tracer gas measurements (a gas used to track airflow). We found that cough-related exposure can remain high even at large distances. Because SEI values from different activities are not directly comparable, we instead calculated a weighted exposure to enable a fairer comparison.
[This summary has been rewritten with the help of AI based on the project's original abstract]
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