Evaluation of indoor environmental quality, personal cumulative exposure dose, and aerosol transmission risk levels inside urban buses in Dalian, China

Zhao, Yu; Gu, Chenmin; Song, Xiaocheng

doi:10.1007/s11356-023-26037-x

Cited by 4 publications

(2 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here, CO 2 is used as an indicator for the quality of the air exchange, by observing the natural exhalation of the persons present in the room. Monitoring the indoor CO 2 concentration in the context of SARS-CoV-2 has been carried out in various settings, e.g., theatres [19], buses [20], hospitals [21], and classrooms [22][23][24][25]. That this approach is helpful has been shown by, e.g., Di Gilio et al, who derived an effective air exchange strategy for classrooms by using the real-time visualization and monitoring of CO 2 concentrations [25].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Surrogate Aerosol Experiments to Predict Spreading and Removal of Virus-Laden Aerosols

Beimdiek,

Schmid

2024

Atmosphere

View full text Add to dashboard Cite

Estimating the infection risks of indoor environments comprises the assessment of the behavior of virus-laden aerosols, i.e., their spreading, mixing, removal by air purifiers, etc. A promising experimental approach is based on using non-hazardous surrogate aerosols of a similar size, e.g., salt particles, to mimic virus aerosol behavior. This manuscript addresses the issue of how a successful transfer of such experiments can be accomplished. Corresponding experiments in two very different environments, a large community hall and a seminar room, with the optional use of air purifiers in various constellations, are conducted. While high particle concentrations are advantageous in terms of avoiding the influence of background aerosol concentrations, it is shown that the appropriate consideration of aggregation and settling are vital to theoretically describe the experimentally determined course of particle concentrations. A corresponding model equation for a well-mixed situation is derived, and the required parameters are thoroughly determined in separate experiments independently. It is demonstrated that the clean air delivery rates (CADRs) of air purifiers determined with this approach may differ substantially from common approaches which do not explicitly take aggregation into account.

show abstract

Section: Introductionmentioning

confidence: 99%

Evaluation of Surrogate Aerosol Experiments to Predict Spreading and Removal of Virus-Laden Aerosols

Beimdiek,

Schmid

2024

Atmosphere

View full text Add to dashboard Cite

show abstract

“…They categorized the risk of infection using the CO 2 concentration and listed the actions to be taken in each category; < 700 ppm (low risk), no action; < 800 ppm (moderate risk), door always open; < 1000 ppm (high risk), door always open and windows open for 10 min at midday; and 1000 ppm (very high risk), door always open and windows open for 10 min at the end of the teaching hour. Zhao et al ( 2023 ) reported that in the absence of source other than the metabolic activity of humans inside the room, the CO 2 concentration can reflect breathing and ventilation conditions. We considered the use of indoor CO 2 concentration as an indicator of ventilation to predict airborne transmission.…”

Section: Introductionmentioning

confidence: 99%

SARS-CoV-2 airborne infection probability estimated by using indoor carbon dioxide

Iwamura

Tsutsumi

2023

Environ Sci Pollut Res

View full text Add to dashboard Cite

Airborne transmission is one of the main routes of SARS-CoV-2 spread. It is important to determine the circumstances under which the risk of airborne transmission is increased as well as the effective strategy to reduce such risk. This study aimed to develop a modified version of the Wells-Riley model with indoor CO2 to estimate the probability of airborne transmission of SARS-CoV-2 Omicron strains with a CO2 monitor and to evaluate the validity of this model in actual clinical practices. We used the model in three suspected cases of airborne transmission presented to our hospital to confirm its validity. Next, we estimated the required indoor CO2 concentration at which R0 does not exceed 1 based on the model. The estimated R0 (R0, basic reproduction number) based on the model in each case were 3.19 in three out of five infected patients in an outpatient room, 2.00 in two out of three infected patients in the ward, and 0.191 in none of the five infected patients in another outpatient room. This indicated that our model can estimate R0 with an acceptable accuracy. In a typical outpatient setting, the required indoor CO2 concentration at which R0 does not exceed 1 is below 620 ppm with no mask, 1000 ppm with a surgical mask and 16000 ppm with an N95 mask. In a typical inpatient setting, on the other hand, the required indoor CO2 concentration is below 540 ppm with no mask, 770 ppm with a surgical mask, and 8200 ppm with an N95 mask. These findings facilitate the establishment of a strategy for preventing airborne transmission in hospitals. This study is unique in that it suggests the development of an airborne transmission model with indoor CO2 and application of the model to actual clinical practice. Organizations and individuals can efficiently recognize the risk of SARS-CoV-2 airborne transmission in a room and thus take preventive measures such as maintaining good ventilation, wearing masks, or shortening the exposure time to an infected individual by simply using a CO2 monitor.

show abstract

Distribution characteristics of inhalable particulate pollutants and their effects on cardiopulmonary respiratory system of outdoor football players in a smart healthcare system

Liu,

Tang,

Zhang

2024

Soft Comput

View full text Add to dashboard Cite

Evaluation of indoor environmental quality, personal cumulative exposure dose, and aerosol transmission risk levels inside urban buses in Dalian, China

Cited by 4 publications

References 68 publications

Evaluation of Surrogate Aerosol Experiments to Predict Spreading and Removal of Virus-Laden Aerosols

Evaluation of Surrogate Aerosol Experiments to Predict Spreading and Removal of Virus-Laden Aerosols

SARS-CoV-2 airborne infection probability estimated by using indoor carbon dioxide

Distribution characteristics of inhalable particulate pollutants and their effects on cardiopulmonary respiratory system of outdoor football players in a smart healthcare system

Contact Info

Product

Resources

About