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Particle exposure risk to a lavatory user after flushing a squat toilet

Squat toilets are widely used in developing countries due to local customs and low costs. The flushing of a squat toilet can entrain strong airflow and produce aerosols. This investigation constructed a lavatory mock-up with a squat toilet. The flushing-induced airflow was both visualized and quanti...

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Autores principales: Zhang, Tengfei (Tim), Yao, Lifang, Gao, Zilong, Wang, Feng
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9726816/
https://www.ncbi.nlm.nih.gov/pubmed/36473899
http://dx.doi.org/10.1038/s41598-022-25106-4
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author Zhang, Tengfei (Tim)
Yao, Lifang
Gao, Zilong
Wang, Feng
author_facet Zhang, Tengfei (Tim)
Yao, Lifang
Gao, Zilong
Wang, Feng
author_sort Zhang, Tengfei (Tim)
collection PubMed
description Squat toilets are widely used in developing countries due to local customs and low costs. The flushing of a squat toilet can entrain strong airflow and produce aerosols. This investigation constructed a lavatory mock-up with a squat toilet. The flushing-induced airflow was both visualized and quantitatively measured by particle image velocimetry. The maximum height of the impacted airflow was identified by an ultrasonic anemometer. For inference of the particle emission rate, the toilet bowl was covered by an enclosed box for particle concentration measurement. The risks from skin contact of the deposited particles on the flushing button and the door handle and the possible inhalation of the released aerosols were evaluated. The results revealed that flushing a squat toilet can drive toilet plume to rise up to 0.9 m above the toilet bowl. A single flushing process can produce 0.29 million particles with diameters greater than 0.3 μm, among which 90% of the particles are submicron-sized. The flushing may cause particles to deposit on the flushing button and lavatory door handle as well as inhalation exposure even remaining in the lavatory for half a minute after flushing, especially for those lavatory users whose respiratory zones are below 1.0 m.
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spelling pubmed-97268162022-12-08 Particle exposure risk to a lavatory user after flushing a squat toilet Zhang, Tengfei (Tim) Yao, Lifang Gao, Zilong Wang, Feng Sci Rep Article Squat toilets are widely used in developing countries due to local customs and low costs. The flushing of a squat toilet can entrain strong airflow and produce aerosols. This investigation constructed a lavatory mock-up with a squat toilet. The flushing-induced airflow was both visualized and quantitatively measured by particle image velocimetry. The maximum height of the impacted airflow was identified by an ultrasonic anemometer. For inference of the particle emission rate, the toilet bowl was covered by an enclosed box for particle concentration measurement. The risks from skin contact of the deposited particles on the flushing button and the door handle and the possible inhalation of the released aerosols were evaluated. The results revealed that flushing a squat toilet can drive toilet plume to rise up to 0.9 m above the toilet bowl. A single flushing process can produce 0.29 million particles with diameters greater than 0.3 μm, among which 90% of the particles are submicron-sized. The flushing may cause particles to deposit on the flushing button and lavatory door handle as well as inhalation exposure even remaining in the lavatory for half a minute after flushing, especially for those lavatory users whose respiratory zones are below 1.0 m. Nature Publishing Group UK 2022-12-06 /pmc/articles/PMC9726816/ /pubmed/36473899 http://dx.doi.org/10.1038/s41598-022-25106-4 Text en © The Author(s) 2022 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) .
spellingShingle Article
Zhang, Tengfei (Tim)
Yao, Lifang
Gao, Zilong
Wang, Feng
Particle exposure risk to a lavatory user after flushing a squat toilet
title Particle exposure risk to a lavatory user after flushing a squat toilet
title_full Particle exposure risk to a lavatory user after flushing a squat toilet
title_fullStr Particle exposure risk to a lavatory user after flushing a squat toilet
title_full_unstemmed Particle exposure risk to a lavatory user after flushing a squat toilet
title_short Particle exposure risk to a lavatory user after flushing a squat toilet
title_sort particle exposure risk to a lavatory user after flushing a squat toilet
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9726816/
https://www.ncbi.nlm.nih.gov/pubmed/36473899
http://dx.doi.org/10.1038/s41598-022-25106-4
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