Airborne Causes of Disease

Special law to aid 2.27 million victims from Korea's humidifier disinfectants finally passes.

During January 26–February 10, 2020, an outbreak of 2019 novel coronavirus disease in an air-conditioned restaurant in Guangzhou, China, involved 3 fa...

The Influenza A H1N1 virus can be transmitted via direct, indirect, and airborne route to non-infected subjects when an infected patient coughs, which expels a number of different sized droplets to the surrounding environment as an aerosol. The objective of the current study was to characterize the human cough aerosol pattern with the aim of developing a standard human cough bioaerosol model for Influenza Pandemic control. 45 healthy non-smokers participated in the open bench study by giving their best effort cough. A laser diffraction system was used to obtain accurate, time-dependent, quantitative measurements of the size and number of droplets expelled by the cough aerosol. Voluntary coughs generated droplets ranging from 0.1 - 900 microns in size. Droplets of less than one-micron size represent 97% of the total number of measured droplets contained in the cough aerosol. Age, sex, weight, height and corporal mass have no statistically significant effect on the aerosol composition in terms of size and number of droplets. We have developed a standard human cough aerosol model. We have quantitatively characterized the pattern, size, and number of droplets present in the most important mode of person-to-person transmission of IRD: the cough bioaerosol. Small size droplets (< 1 μm) predominated the total number of droplets expelled when coughing. The cough aerosol is the single source of direct, indirect and/or airborne transmission of respiratory infections like the Influenza A H1N1 virus. Open bench, Observational, Cough, Aerosol study

Evidence is emerging that warmer temperatures and higher humidity can indeed affect the disease’s spread.

A Web Application to develop particle size distributions for use in CONTAM evaluations of airflow. National Institute of Standards and Technology tool

National Center for Biotech Info

Respiratory viral diseases can be spread when a virus-containing particle (droplet) from one individual is aerosolized and subsequently comes into eit…

Size distributions of expiratory droplets expelled during coughing and speaking and the velocities of the expiration air jets of healthy volunteers were measured. Droplet size was measured using the interferometric Mie imaging (IMI) technique while the ...

[*Methods & tools for sampling aerosols noted in this study & in references listed at end] Background Influenza virus was used to characterize the efficacy of a cyclone‐based, two‐stage personal bioaerosol sampler for the collection and size fractionation of aerosolized viral particles. Methods A Collison single‐jet ...

A blog about hospital infection prevention.

The COVID-19 pandemic caused the shutdown of entire nations all over the world. In addition to mobility restrictions of people, the World Health Organization and the Governments have prescribed maintaining an inter-personal distance of 1.5 or 2 m (about ...

This Viewpoint discusses physical and epidemiological evidence supporting droplet vs aerosol transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and concludes on balance that aerosol transmission seems unlikely to be the dominant mode of coronavirus disease 2019 (COVID-19)...

[*Ventilation may not be applicable for respiratory infections in hospital rooms.] Our discussion of the …

(1986). Airborne Microbial Contaminants in Indoor Environments. Naturally Ventilated and Air-Conditioned Homes. Archives of Environmental Health: An International Journal: Vol. 41, No. 5, pp. 306-311.

(2008). Airborne Fungal and Bacterial Levels Associated With the Use of Automobile Air Conditioners or Heaters, Room Air Conditioners, and Humidifiers. Archives of Environmental & Occupational Health: Vol. 63, No. 3, pp. 101-107.

Primary route of transmission of SARS-CoV-2 among humans is droplets and direct contact. Airborne transmission of this virus is not established conclusively and so is the role of airborne particulate matter. This commentary examines the existing evidence about the role of particulate matter pollutan …

This study has two goals. The first is to explain the geo-environmental determinants of the accelerated diffusion of COVID-19 that is generating a high level of deaths. The second is to suggest a strategy to cope with future epidemic threats similar to COVID-19 having an accelerated viral infectivit …

Indoor air can be an important vehicle for a variety of human pathogens. This review provides examples of airborne transmission of infectious agents from experimental and field studies and discusses how airborne pathogens can contaminate other parts of ...

Understanding How many air changes per hour are needed can help you chooose the right air purifier for your needs. This page shows you EPA recomendations.

Fresh air - or make up air - requirements - recommended air change rates - ACH - for typical rooms and buildings - auditoriums, kitchens, churches and more

Calculate air change rates - equations in imperial and SI units

As excessive exposure to airborne particulate matter (PM) results in adverse health effects, the development of real-time PM monitoring is highly relevant. The

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[*Used air sampler]. The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in Wuhan, China in late 2019, and its resulting coronavirus disease, COVID-19, was declared a pandemic by the World Health Organization on March 11, 2020. The rapid global ...

ICU & toilet tested positive. Room ventilation, open space, proper use and disinfection of toilet can effectively limit aerosol transmission of SARS-CoV-2. Gathering of crowds with asymptomatic carriers is a potential source of airborne SARS-CoV-2. The virus aerosol deposition on protective apparel or floor surface and their subsequent resuspension is a potential transmission pathway

"Furthermore, a small fraction of individuals behaves as “speech superemitters,” consistently releasing an order of magnitude more particles than their peers. Our data demonstrate that the phenomenon of speech superemission cannot be fully explained either by the phonic structures or the amplitude of the speech. These results suggest that other unknown physiological factors, varying dramatically among individuals, could affect the probability of respiratory infectious disease transmission, and also help explain the existence of superspreaders who are disproportionately responsible for outbreaks of airborne infectious disease."

Movement of objects can spread contagion in air -Background The ongoing outbreak of COVID-19 has spread rapidly and sparked global concern. While the transmission of SARS-CoV-2 through human respiratory droplets and contact with infected persons is clear, the aerosol transmission of SARS-CoV-2 has been little studied. Methods Thirty-five aerosol samples of three different types (total suspended particle, size segregated and deposition aerosol) were collected in Patient Areas (PAA) and Medical Staff Areas (MSA) of Renmin Hospital of Wuhan University (Renmin) and Wuchang Fangcang Field Hospital (Fangcang), and Public Areas (PUA) in Wuhan, China during COVID-19 outbreak. A robust droplet digital polymerase chain reaction (ddPCR) method was employed to quantitate the viral SARS-CoV-2 RNA genome and determine aerosol RNA concentration. Results The ICU, CCU and general patient rooms inside Renmin, patient hall inside Fangcang had undetectable or low airborne SARS-CoV-2 concentration but deposition samples inside ICU and air sample in Fangcang patient toilet tested positive. The airborne SARS-CoV-2 in Fangcang MSA had bimodal distribution with higher concentration than those in Renmin during the outbreak but turned negative after patients number reduced and rigorous sanitization implemented. PUA had undetectable airborne SARS-CoV-2 concentration but obviously increased with accumulating crowd flow. Conclusions Room ventilation, open space, proper use and disinfection of toilet can effectively limit aerosol transmission of SARS-CoV-2. Gathering of crowds with asymptomatic carriers is a potential source of airborne SARS-CoV-2. The virus aerosol deposition on protective apparel or floor surface and their subsequent resuspension is a potential transmission pathway and effective sanitization is critical in minimizing aerosol transmission of SARS-CoV-2.