Stopping pathogens | Sunday Observer

Stopping pathogens

Did you know that we cannot live without air for more than three short minutes? Although some divers have perfected the art of not taking a breath for more than three minutes, the average human will not be able to survive without access to air for more than three minutes.

In today’s world, air is not just nitrogen and oxygen. It has many pollutants and pathogens (bacteria and viruses) too. We have to inhale these elements too, and there is little or no natural filtration by the body. Worldwide, millions die each year as a result of these two factors. There are many air-conditioning and air purifying systems that claim to take out pollutants and pathogens from the air we inhale, but these are limited to indoors at best and are essentially not 100 percent effective in any case.

What if we can purify outdoor air as well? There are some technologies that reduce the emissions of pollutants at the source – catalytic converters in cars and scrubbers in industrial plants are just two examples, but so far there has been little success in ‘taking out’ pathogens and pollutants that already exist in the air. Another technique used in the medical field is Ultraviolet germicidal irradiation which uses ultraviolet light to kill or inactivate microorganisms by destroying their DNA. But this is said to have many side effects.

The crux of the matter is that airborne diseases are easily transmitted and can result in respiratory illness that can be life threatening. Viruses that can spread through the air include the flu, common cold (rhinovirus), varicella zoster (chicken pox), mumps and measles. Matters have been made worse worldwide as some parents refuse to vaccinate their children, a trend that we focused on in an earlier column.

Worse, infected individuals can easily transmit viruses when they sneeze or cough. Thus viruses can spread very quickly from one person to another through the etherand even go worldwide due to global travel. According to the World Health Organization, the flu alone results in more than 3 million cases of severe illness per year and around 500,000 deaths. The Spanish flu (H1N1) in 1918-1919 infected about a quarter of the global population and led to more than 40 million deaths.

A potential answer to this problem is non-thermal plasma – a cool gas made up of electrically charged particles, despite having no overall charge. These already have many applications, including in the plasma TVs of days gone by and also in the food industry. But new research has shown that non-thermal plasma could inactivate airborne viruses and provide sterile, pure air. Further refinement of this technology could be a game-changer in our relentless fight against microbes that cause disease and death.

The new method has been developed by researchers at the University of Michigan. In a new study published in the Journal of Physics, they show that non-thermal plasma can inactivate 99.9% of airborne viruses through releasing energetic, charged fragments of air molecules that can destroy viruses in milliseconds. Furthermore, it can also kill bacteria by destroying their cellular structure, according to the researchers.

The technology behind this new development is somewhat complex. The plasma is produced in a non-thermal plasma reactor. When pathogens in the air pass through it, they react with unstable atoms called radicals which alter the lipids, proteins and nucleic acids of the microorganisms. This either kills the pathogens or renders them ineffective. It also has a filtration stage. Thus it combines filtration and inactivation of airborne pathogens in one go, whereas existing systems try to tackle these aspects separately. The new method will therefore be more efficient than the current ones. Animal trials are currently underway to determine its efficacy and human trials could commence soon.

This is good news indeed, but commercialization may be many years away. Any side effects will also have to be studied. The cost factor will also have to be taken into account as only developed countries will be able to afford any new advanced technology that can potentially thwart pathogens. It is possible that the technology could be licensed to third party manufacturers at some point, which will essentially lower the costs as economies of scale come into play over time.

I have no doubt that some readers of this column have installed air purifying air-conditioners and other mechanisms in their homes and offices. But there are many simple steps that we can take to limit our exposure to pathogens, that cost little or no money at all. The first step is hand washing. Washing hands with soap or cleansing liquids after using the bathroom and at other appropriate times can prevent the spread of many diseases. All you need is soap and water and both are not expensive at all. The hand washing habit must be inculcated in children from a very young age.

Wearing a simple face mask is another solution, especially, if you go out in highly polluted environments (A surgical grade mask is even better). While this is primarily effective for preventing the entry of polluted air into your lungs (which is in itself beneficial), it does have the potential to stop some pathogens as well. Covering your nose and mouth with a handkerchief when you sneeze or cough is a good habit that can possibly spread any pathogens that you already have among other people. Also, you should stop sharing cups and plates with family members or colleagues when you are sick. If possible, avoid coming into contact with the outside world for a few days. Rest is the best cure for many virus based diseases which actually have no cure in that sense of the word.

The other major takeaway is the importance of vaccination. There is unfortunately a somewhat misguided campaign against vaccination in most parts of the world which has already created havoc in many countries, especially, with regard to measles. Fortunately, Sri Lankans have not fallen prey to this campaign, founded mostly on falsehoods and phobias. The benefits of vaccination far outweigh its disadvantages, if any. Regardless of whether one is an adult or a child, vaccination is still the number one way of preventing diseases. Hence, the scientists’ race to develop vaccinations for diseases such as AIDS and even cancer. It is important to get vaccines if you are travelling to certain regions of the world or if you think you could be prone to a certain disease for which a vaccine is available. We do not think twice about getting a tetanus shot after a rusty nail goes into a sole – likewise, vaccination should be second nature in the fight against diseases. We might not win the fight against microbes at all times, but there are many steps we can take to defeat their designs.

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