A research team comprising scientists from the United States, Canada and Spain have revealed that more than 800 million viruses fall on every square metre of the planetary boundary layer (the lowest part of the atmosphere) every day.

That is the equivalent of 12 viruses for every person in the UK and 25 viruses per person in Canada. The risk of getting an infection through virus is high as unlike bacteria rain cannot wash them away.

Responding to coronavirus (COVID-19) fears, Camfil has issued a statement providing advice on protection from infection.

“While most of us don’t have the power to make the air cleaner, there are some things individuals can do to reduce the effect of these infectious particulates in the air,” the statement said.

“HEPA filters have been proven over decades across a wide range of healthcare facilities and life sciences applications, controlling the spread of airborne particles and organisms such as viruses and bacteria.

“Many professional engineering organisations recommend HEPA (high efficiency particulate air filters) in hospitals, infection control clinics and other healthcare facilities to eliminate microbes and other dangerous particles.”

True high-efficiency particulate air (HEPA) filters most commonly are rated by test methods that begin with a minimum capture efficiency. The efficiency of HEPA filters is measured at MPPS (most penetrating particle size) that means this is the lowest efficiency of the filter. For smaller or larger particles that filter will perform even better.

MPPS is typically between 0,1-0,25 micrometer in size.

“Bacteria and viruses are often smaller than that but typically attach themselves to larger particles. It’s also important to understand HEPA filters do not actively kill living organisms. They capture and hold them within the matrix of the filter,” Camfil explained.

“High efficiency air filters (HEPA)  can be installed in HVAC systems, filtering out biological pollutants and particulate matter carried by the air-stream, preventing them from entering or recirculating back into the room.

“As unfiltered air flows through the HVAC unit’s duct-work, the air filter captures and holds the airborne pollutants.

“For further risk mitigation of airborne pathogens, it is recommended to upgrade or install the highest possible efficiency HEPA filtration (H13 or higher) in the existing ventilation system. This will improve your chances to avail an extra layer of protection against airborne pathogens.”

Virus containment at health care facilities and bio-safety labs is very much about control measures and precautions for airborne exposure.

Camfil said measures include ventilation, pressure differentials, exhaust ventilation, air filtration and cleaning, ultraviolet and germicidal irradiation (UVGI) and even temperature and humidity control. 

Air filtration solutions depend on the category of the risk when in application.

“High density areas with most affected surroundings such as laboratories, containment units, quarantined zones need much higher level of protection compare to low risk exposure surroundings or controlled areas like homes or small business space. High risk application needs air containment and filtration equipment of HEPA Class H13 or higher along with use of special personnel equipment and clothing, as well as a segregated air supply, among other precautions,” the statement said.

Camfil suggested using air cleaners for fast and easy retrofit in case of a sub-standard ventilation system to improve air filtration.

“It is also a way to rapidly boost the air quality of an already good functioning system when there is an increased risk that demands even better protection,” the statement said.

For crucial high-risk applications such as quarantined zones and laboratories Camfil provides compelling containment equipment.

“However, an air cleaner is recommended for use where the risk of airborne contamination is elevated. Both containment units and air cleaners cannot be installed anywhere as they are specific to the risk and nature of the surroundings, but an air cleaner can never replace a full containment set where there is a need,” Camfil said.

“On the other hand, low risk applications can consider using EPA filters or ePM1 80% or higher category of air filtration.”





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