I AM deeply concerned by the news that several government agencies (not the Health Ministry) have ordered and set up Covid-19 disinfection tunnels in several locations. I became even more distressed after reading that some of our local universities and innovators are manufacturing these disinfection tunnels.
My first reservation is on the evidence-base of the effectiveness of a Covid-19 disinfection tunnel. While the exact mode of Covid-19 transmission has not been fully determined, we do know that human-to-human transmission occurs through small droplets from the nose or mouth, which spread when a person with the coronavirus coughs, sneezes or exhales. These droplets land on objects and surfaces around the person.
Other people could then catch the coronavirus by first touching these objects or surfaces and then touching their eyes, nose or mouth. People can also catch the coronavirus if they breathe in droplets from a person with Covid-19 who coughs out or exhales droplets. This is why one of the key health advisories is social distancing.
To date, there is conflicting data on how long the virus can remain viable on garments. The targets for the disinfection tunnel are the garments people are wearing. However, a garment that you are wearing right now cannot be considered as a frequently touched surface if you are already practising social distancing.
The disinfection tunnel will not kill any virus already present in your nose, throat or body, hence a person infected with Covid-19 will remain infectious even after passing through the tunnel.
My second reservation concerns the negative impact of the disinfection solutions on health. Most disinfection solutions (of the appropriate strength) are never meant to be exposed to human skin and mucosal membranes, particularly the eyes. Most disinfection solutions are chlorine-based i.e. bleach. Repetitive exposure to even diluted solutions may cause irritation, inflammation and allergic reactions. If the solution is too diluted, then it will not be effective for its intended purpose.
Thirdly, there is the issue of the run-off or waste water from these disinfection tunnels. Depending on the types of disinfection solutions being used, these must also be disposed of appropriately, otherwise we will contribute to environmental pollution unintentionally.
Lastly, and most importantly, I am most concerned that these disinfection tunnels would give the users a false sense of security. Just because of these tunnels, they may not practise social distancing, they don’t wash their hands properly and as often as they should, and they still touch their face with unwashed hands. Worst is the false sense of protection that by passing through the tunnel, you will not be infective to others anymore through the droplets that come out when you speak, sneeze or cough.
For our non-healthcare worker frontliners, the recommendations are to avoid touching your face and face mask, take a bath right after you get home, wash your outdoor clothes immediately and practise social distancing as best as you can.
Disinfection or decontamination tunnels do have their utilities in specified biological and chemical incidents, and their use are controlled and regulated for the personnel directly involved. But their use to stop the spread of Covid-19 as yet do not have the scientific evidence of effectiveness and definitely should not be used for the general public in a community or workplace setting.
I have challenged the effectiveness of non-targeted disinfection of public places and I am astonished that we are now going into this.
We have limited resources and we must use what we have wisely. Due to shortage of personal protective equipment (PPE), Malaysians have become innovative. Many parties have contributed in making some of these PPE’s, for example face shields, protective garments and even intubation boxes.
Perhaps we can ask our universities and innovators to help design Malaysia’s mobile non-contact Covid-19 testing chambers instead, like the ones used in South Korea. This will further protect our frontliners and assist the Health Ministry as we move towards mass screening of affected populations.
Prof Datuk Dr Lokman Hakim Sulaiman
Pro-Vice Chancellor (Research)
Professor of Public Health
International Medical University