Donald K. Milton's research while affiliated with Loyola University Maryland and other places

Publications (16)

Article
Full-text available
The exhalation of aerosols during musical performances or rehearsals posed a risk of airborne virus transmission in the COVID‐19 pandemic. Previous research studied aerosol plumes by only focusing on one risk factor, either the source strength or convective transport capability. Furthermore, the source strength was characterized by the aerosol conc...
Article
Policies to prevent respiratory virus transmission in health care settings have traditionally divided organisms into Droplet versus Airborne categories. Droplet organisms (for example, influenza) are said to be transmitted via large respiratory secretions that rapidly fall to the ground within 1 to 2 meters and are adequately blocked by surgical ma...
Article
Full-text available
Eighteen months into the COVID-19 pandemic, and as the world struggles with global vaccine equity, emerging variants, and the reality that eradication is years away at soonest, we add to notion of “layered defenses” proposing a conceptual model for better understanding the differential applicability and effectiveness of precautions against SARS-CoV...
Article
No PDF available ABSTRACT Outbreaks from choirs showed that singing brings potential risk of COVID-19 infection. There is less known about the risks of airborne infection from other musical performance, such as playing wind instruments or performing theatre. In addition, it is important to understand methods to reduce infection risk. In this study,...
Article
Full-text available
Outbreaks from choir performances, such as the Skagit Valley Choir, showed that singing brings potential risk of COVID-19 infection. There is less known about the risks of airborne infection from other musical performances, such as playing wind instruments or performing theater. In addition, it is important to understand methods that can be used to...
Article
Background: Multiple SARS-CoV-2 superspreading events suggest that aerosols play an important role in driving the COVID-19 pandemic. To better understand how airborne SARS-CoV-2 transmission occurs, we sought to determine viral loads within coarse (>5μm) and fine (≤5μm) respiratory aerosols produced when breathing, talking, and singing. Methods:...
Preprint
Full-text available
Background Multiple SARS-CoV-2 superspreading events suggest that aerosols play an important role in driving the COVID-19 pandemic. However, the detailed roles of coarse (>5μm) and fine (≤5μm) respiratory aerosols produced when breathing, talking, and singing are not well-understood. Methods Using a G-II exhaled breath collector, we measured viral...
Article
Full-text available
Understanding the particle size distribution in the air and patterns of environmental contamination of SARS-CoV-2 is essential for infection prevention policies. Here we screen surface and air samples from hospital rooms of COVID-19 patients for SARS-CoV-2 RNA. Environmental sampling is conducted in three airborne infection isolation rooms (AIIRs)...
Article
Full-text available
During the rapid rise in COVID-19 illnesses and deaths globally, and notwithstanding recommended precautions, questions are voiced about routes of transmission for this pandemic disease. Inhaling small airborne droplets is probable as a third route of infection, in addition to more widely recognized transmission via larger respiratory droplets and...
Preprint
Full-text available
Background: Understanding the particle size distribution in the air and patterns of environmental contamination of SARS-CoV-2 is essential for infection prevention policies. Objective: To detect the surface and air contamination by SARS-CoV-2 and study the associated patient-level factors. Design: Cross-sectional study. Setting: Airborne infection...
Article
Full-text available
Strategies to protect building occupants from the risk of acute respiratory infection (ARI) need to consider ventilation for its ability to dilute and remove indoor bioaerosols. Prior studies have described an association of increased self-reported colds and influenza-like symptoms with low ventilation but have not combined rigorous characterizatio...
Article
Pulmonary infections are important causes of global morbidity and mortality, but diagnostics are often limited by the ability to collect specimens easily, safely and in a cost-effective manner. We review recent advances in the collection of infectious aerosols from patients with tuberculosis and with influenza. Although this research has been focus...

Citations

... Therefore, in similar fashion to vocalization, one could hypothesize that playing of wind instruments could lead to emission of respiratory aerosols from breathing and subsequent aerosolization of saliva from the vibrating instrument. Recent work supports this hypothesis 8,9,26,27 , but published literature is somewhat contradictory regarding the magnitude of emissions from different instruments. There is also uncertainty regarding sex and age effects and whether available mitigation measures (i.e., bell covers) are effective at reducing emissions and subsequent exposure risks. ...
... Finally, over half of the studies did not list specific AGMPs but instead combined multiple procedures into the category of AGMP or did not define their AGMP group. Lack of describing the AGMP and identifying potential confounders precludes distinguishing whether the increased risk of VRI during AGMPs is due to the procedure itself or the circumstances in which the procedures are being performed [4,14,69,70]. For example, the increased risk observed among certain procedures may be explained by symptoms experienced by the patient, viral load, proximity of the HCW to the patient during the procedure, and duration of the exposure [4,70]. ...
... However, not all workplace hazards can be eliminated, necessitating establishing some protective measures to minimize workplace exposure to any form of danger. Personal protective equipment (PPE) is used to mitigate workplace hazards when available measures cannot eliminate the risk at the source [1][2][3][4]. PPE serves as a key to personal safety at the worker level in minimizing the chances of exposure to occupational hazards and injuries in the construction industry [4][5][6][7][8][9]. ...
... The local air concentration of aerosol has been found to decay to background level on a sub-meter length scale which indicates efficient aerosol dilution in the ambient air 22 . The plume generated by playing the clarinet has been found to be highly directional, to have high velocity, and to disperse quickly 24 . No air motion could be measured in 2 m distance in front of woodwinds which was the largest reach of aerosol clouds observed 20,21 . ...
... The number of aerosols as well as the viral RNA strongly depend on the subject and the respiratory activity. Coleman [3] analysed the viral load in aerosols from 22 COVID-19 patients, detecting RNA in 13 (59%) of them, with viral loads ranging between 63 to 5,821 nucleocapsid (N) gene copies of SARS-CoV-2. The major aerosol emission was detected during singing (53%), followed by talking (41%), and finally, by breathing (6%). ...
... The size distribution of the virion-containing particles is understudied and the particle size distributions produced from respiratory activities vary widely under different respiratory scenarios (Asadi et al., 2019;Bourouiba et al., 2014;Gregson et al., 2021;Gupta et al., 2010;Han et al., 2013;Lindsley et al., 2016;Stadnytskyi et al., 2020;Yang et al., 2007). However, breathing, the most common respiratory activity, typically generates not only more fine particles (< 5 µm) but also a higher proportion of fine particles with viral RNA attached, suggesting these particles are at least partially responsible for respiratory disease spread (Coleman et al., 2021;Fabian et al., 2008;Yan et al., 2018). With low settling velocities, such particles can remain suspended in the air for minutes-tohours (Thatcher et al., 2002), and particles in this size range that are virion-containing contribute to infectious disease transmission via two routes. ...
... Depending on the surface attributes, the deposited particulate matter can lead to surface contamination, performance degradation, and pathogen and virus transmission. 1,2 The most relevant modern example is the poorly understood pathway for droplet and aerosol (∼10 μm) transmission of COVID-19 when interacting with surfaces in confined spaces (indoors). 1,2 A second example is the accumulation of dust on solar−thermal mirrors and photovoltaic panels, which results in a reduction of energy conversion efficiency by up to 40% due to optical absorption losses. ...
... Once the continuous phase solution converges at each time step, the trajectory of the discrete phase (pathogen-laden solid aerosol) is tracked through the Lagrangian technique (DPM) based on the airflow solution. It has been reported that the human exhalation droplet size spans a wide range of 0.01-1000 μm; however, we only consider the aerosol particles < 5 μm, which will follow the airflow faithfully (WHO, 2014;Bake et al., 2019;Fennelly, 2020;Milton, 2020). It is because the droplet aerosols of O(10 μm) evaporate within 0.1-1 s (Redrow et al., 2011) and those of O (100 μm) are directly settled on the floor or other nearby surfaces . ...
... Furthermore, these studies provided evidence of SARS-CoV-2 viral RNA 140 , or infectious RSV 141 , Middle East respiratory syndrome-related coronavirus 142 and SARS-CoV-2 (reF. 143 do not support the letter's claim of the importance of aerosols in SARS-CoV-2 transmission; for example, the lack of observed long-range transmission or observed increased risk of infection among health-care workers in the absence of airborne precautions 150 , which the authors of the open letter responded to 151 . On 9 July, the WHO issued a updated scientific brief 39 , citing some of the evidence described in the open letter 132 and extensive subsequent evidence on SARS-CoV-2 transmission. ...
... However, while face-to-face interactions provide a good approximation of conversations and are useful for social interaction analysis [9,57], when studying SARS-CoV-2 transmission this aspect is less critical. Indeed, several researchers are highlighting that SARS-CoV-2 can spread among people occupying the same space, whether or not they are facing one another [58,59]. ...