Public Health Issue of Indoor Dilution Ventilation for Disease Prevention Versus PM2.5 in Intake Air in Auditoriums of Premier Engineering Institutes in India.

BACKGROUND: Dilution ventilation by enhancing fresh air intake has been prescribed to reduce airborne infection spread during the COVID-19 pandemic. This is all the more important in assembly spaces like auditoriums. Premier technology institutes have large campuses with large auditoriums for academic and cultural events in India. These institutes serve as role models for society, where gatherings are essential, but there is also the possibility of transmission of all airborne respiratory infections, including tuberculosis, into the community. The fresh air taken in should also be filtered for pollution to prevent other lung issues. AIMS: Fresh air intake and filtration have been studied in order to understand whether the outside air supplied indoors is filtered for PM2.5, which is a major ambient polluter in India. Settings and design/methods: In this study, the Right to Information Act of 2005 has been used to obtain first-hand information from the institutes with respect to the heating, ventilation, and air conditioning (HVAC) systems in their auditoriums. Twelve of the 19 institutes fall in cities with non-attainment of ambient air quality standards. RESULTS: Eleven out of all those had recently integrated fresh air supply, and six replied in the negative. Only one out of all of them had appropriate filters. CONCLUSION: This study highlights the need for a possible trade-off between the use of air conditioners for thermal comfort + assumed protection against PM2.5, which is the switching off of air conditioners and manually opening up windows and using fans for ventilation. Indian HVAC design for gathering spaces, especially educational institutes, needs to factor in fresh air for dilution ventilation as well as PM2.5 filtration.

The Risk Status of Waiting Areas for Airborne Infection Control in Delhi Hospitals.

Background Hospital waiting areas are overlooked from the airborne infection control viewpoint as they are not classified as critical for infection control. This is the area where undiagnosed and potentially infected patients gather with susceptible and vulnerable patients, and there is no mechanism to segregate the two, especially when the potentially infected visitors/patients themselves are unaware of the infection or may be asymptomatic. It is important to know whether hospitals in Delhi, a populated, low-resource setting having community transmission/occurrence of airborne diseases such as tuberculosis, consider waiting areas as critical. Hence, this study aims to determine whether hospitals in Delhi consider waiting areas as critical areas from the airborne infection control viewpoint. Methodology The Right to Information Act, 2005, was used to request information from 11 hospitals included in this study. Results After compiling the results, it was found that five out of the 11 hospitals did not consider waiting areas as critical from the infection spread point of view. Two of the 11 hospitals acknowledged the criticality of waiting areas but did not include the same in the list of critical areas. Only three out of the 11 considered waiting areas as critical and included these in the list of critical areas in a hospital. Conclusions This study provided evidence that most hospitals in Delhi do not include waiting areas in the list of critical areas in a hospital.

Studying the Double Paradox in Air Conditioning at Indian Airports for Airborne Infection Prevention and Filtration of Harmful Suspended Particulate Matter.

Background Airports are hubs of diverse human interactions. During pandemics, they may serve as centers for the spread of airborne infection. Appropriate methods for the prevention of the spread of airborne infections must be integrated into the air conditioning systems of airports. Along with ultraviolet germicidal irradiation and other sanitization methods, dilution ventilation can be the easiest and most available method for the prevention of airborne infection, which means the intake of outside air into the indoors, which flushes out the aerosolized droplets containing pathogens. Though this process has been adopted by multiple buildings in reaction to the pandemic, it may present the challenge of intake of high concentration of suspended particulate matter in the intake air, a major air pollutant in developing countries, which may enter through the air conditioning systems. Appropriate filtration is necessary so that along with dilution ventilation for airborne disease prevention, the risk of suspended particulate matter of diameter 2.5 micron or PM2.5 induced lung issues is also reduced. Methodology The Right to Information Act, 2005, was used to file applications for information on the details of the air conditioning systems in Indian airports. The 58 airports in the study were also listed according to the list of cities that fall under the criteria for non-attainment of good air quality standards. Results Out of 58 airports considered, 27 fell in the 'non-attainment' of good air quality list. On appraisal of filter systems, it was found that 23 had an intake of fresh air but only five had filters with a minimum efficiency reporting value (MERV) of 10 and above in their air conditioning systems, as is recommended for filtration of suspended particulate matter. Conclusion It can be concluded that most airports did not have the appropriate filter required for filtering PM2.5, which is a major pollutant in Indian cities. In light of coronavirus disease 2019, where dilution ventilation through the intake of outdoor air is suggested, it may also lead to the entry of air with high particulate matter into the indoors.