Sneezing
I couldn’t help but touch on this topic of sneezing and coughing as “social distancing” and “masks” have entered mainstream vocabulary. And as we all know, Covid-19 is transmitted via droplets floating in the air when a person sneezes, coughs or exhales. Before we delve deeper into these concepts, I want to first get the dictionary definitions of sneezing and coughing out of the way. According to the US dictionary, sneezing is defined as “Make a sudden involuntary expulsion of air from the nose and mouth due to irritation of one’s nostrils” and coughing is defined as “Expel air from the lungs with a sudden sharp sound”. The common theme in both of these actions is expelling air which will carry liquid droplets. One of the studies has shown that sneezing is controlled by a region of the brian called medulla which is located in the brain stem (part of the brian connected to the spinal cord), whereas no definitive area of the brain has been identified which controls coughing action. Irrespective of which mechanism controls these actions, they are evolved to protect humans and animals alike by expelling harmful organisms and irritants from the body.
We sneeze due to 2 main reasons, one because we are suffering from some type of respiratory infection and another if we are having an allergic reaction. Occasionally, people also sneeze due to non-allergy related causes as well. The lining of the nose gets irritated by either of these events and the instinctive reaction of the body is to get rid of whatever is bothering the nose or is harmful to the body and this comes out in the form of sneezing, thus creating an evolutionary advantage. According to Smithsonian Magazine, it is estimated that a sneeze contains about 40,000 droplets of liquid traveling at a speed of 100 miles an hour. These can travel upto 18 feet in distance. These droplets are usually packed with pathogens such as bacteria and viruses. Based on the size, the tiny droplets either float around in the air for a while just like bubbles as they are too light to fall on the ground. It is such droplets which are the main culprits in spreading diseases such as cold or flu, now Covid-19.
Coughing
Similar principle applies to coughs as this also a reflex action which leads to virus/bacteria droplets floating in air. However, coughs have an interesting history. Researchers claim that cough existed in prehistoric humans thousands of years ago and might have been one of the reasons for spreading respiratory diseases as the individuals lived in groups. There are 2 wide varieties of coughs, a persistent cough which might indicate an underlying health condition and a one off cough. When a person coughs it can travel anywhere from 3 feet- 16 feet in distance, however beyond 3 feet, the droplets fall on the ground. It certainly doesn’t pack a punch like sneezing, but nevertheless Covid-19 seems to use this as an alternative effective weapon to spread from one person to another. Thus ensuring the survival of its own kind.
Viruses in droplets
It is due to the reason for droplets filled with viruses floating around which has led to social distancing and use of masks by the general public, literally all over the world. Masks, even the home-made ones are shown to deflect the droplets thus preventing it from travelling long distances. These practices are geared more towards community protection rather than individual protection. By ensuring that everyone maintains distance and wears a mask, we are reducing the number of droplets carrying viruses in the air, thus in turn reducing the chances of inhaling these harmful viruses such as Covid-19 and getting infected. Irrespective of whether there is strong scientific evidence for correlation between mask usage and prevention of infection, I am a strong believer in using them. This is based on my own personal experience. A few years ago, my mother who suffered from heart condition was hospitalized due to a urinary tract infection from which she recovered and was brought home. I ended up catching a cold due to hospital visits, but still had the responsibility of taking care of her as she was bedridden. I wore a mask and gloves and took care of her for a week even though I was scared that she would catch the infection from me. But, she never got the cold and I think this was due to me using the mask every time I was around her and wearing gloves whenever I touched her.
From me the biggest realization due Covid-19 pandemic is that my care and concern goes beyond just family and friends to the wider community. Yes, I do want to wear a mask and maintain social distancing to protect myself from others and also to protect them from me.
Links for further readinghttps://www.scientificamerican.com/article/why-do-we-sneeze/ https://www.smithsonianmag.com/smithsonian-institution/ask-smithsonian-why-do-we-sneeze-180957634/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3234184/ https://www.google.com/books/edition/Journal_of_the_Association_of_Engineerin/r2tPUz5Gz88C?hl=en&gbpv=1&dq=how+far+do+droplets+travel+when+we+cough&pg=PA282&printsec=frontcover
https://www.sciencefocus.com/the-human-body/how-far-do-coughs-and-sneezes-travel/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2077498/ https://en.wikipedia.org/wiki/Cough_reflex#:~:text=The%20mechanism%20of%20a%20cough,order%20to%20equalise%20the%20pressure. (Royalty free images were downloaded from Pixabay.com)
