Is the outbreak and increasing cases of Coronavirus (COVID-19) onboard the Diamond Princess cruise ship in Japan linked to the ship’s air conditioning system?
For the 3,600 people aboard the Diamond Princess, locked down in their state rooms for more than a week, the ‘lucky’ ones at least have a small balcony or window to look out of. Many others are confined to windowless rooms and at risk of claustrophobia. All are desperate for information on their plight. Despite the quarantine efforts the virus continues to spread on the ship and nobody apparent knows why. Now the biggest concentration of COVID-19 cases outside of Wuhan city is on the Diamond Princess. WHY?
What is a common factor in all the cabins that may be spreading the virus? A possibility is the ship’s central air conditioning unit with recirculated air being pumped to all rooms. Apparently these units only introduce 10-15 % new air as it recycles, in order to save heating costs. While the ship is standing still in port the stale air is not drifting downwind, it will get recirculated back into the system and surrounding area.
Building air-conditioning systems have previously been found to be responsible for the spreading pathogens, such as Legionnaires’ disease.* According to the U.S. CDC , Legionella bacteria can be spread in buildings by occupants inhaling water vapor from air conditioning units, where the legionella bacteria are infesting cooling towers. For example:
*NOTE, I am not suggesting Legionnaires’ disease is at all linked to COVID-19
Quoting from the CDC:
After Legionella grows and multiplies in a building water system, water containing Legionella then has to spread in droplets small enough for people to breathe in. People can get Legionnaires’ disease or Pontiac fever when they breathe in small droplets of water in the air that contain the bacteria.
If this is the case with the people marooned on the Diamond Princess being confined to their cabins is possibly the worst place they could be. A large floating petre dish perhaps…
However, according to the ship’s website they deny this is a possibility to Quote:
Can the coronavirus be spread through the ship’s ventilation system?
A: The HVAC (heating ventilation air-conditioning) filtration system on our ships is comparable to those used by land-based hotels, resorts and casinos.
According to a letter recently sent to cruise ship passengers and crew members onboard cruise ships by Anne Schuchat, principal deputy director at the U.S. CDC, there is no current evidence to suggest that the virus spreads through air-handling systems. Staying in your room and limiting contact with other people are the best ways to minimize exposure.
However Schuchat’s assurance from the CDC is very questionable. If Legionella bacteria can spread in building air-handling systems then why not Coronavirus as well?
As for the possibility of viruses spreading in ventilation systems see the viewpoint from the American Society of Heating, Refrigerating and Air-Conditioning Engineers. They have issued a report that suggests that ventilation systems could spread droplets infected with the flu virus when someone sneezes or coughs.
According to the ABC News it has been acknowledged in Japan that the virus is spreading in the ship.
It is perhaps understandable that the cruse company would deny this because if the air-conditioning system was found to have spread a pathogen there is an issue of public liability and litigation. See:
To quote from the insurance company :
When people are infected with legionella from an establishment, its owners and/or operators can be held liable for victims’ physical and financial suffering. Since just one uninsured lawsuit can be enough to plunge a company financial jeopardy, having Environmental Impairment Liability insurance should be considered a cost of doing business.
And from GLE a leading integrated architecture, engineering, and environmental consulting firm:
What is The Property Owner’s Liability in the Event of a Legionnaires’ Outbreak? In the event of a Legionnaires’ outbreak on your property, there are three main consequences that can cost you:
Claims coronavirus can spread through the air
For the Diamond Princess owners, how will they ever clean up the ship?
Also see photos from the ship:Leave a reply →