David Keisler

David Keisler

Soap was probably discovered by accident at least 2,800 years BC. The fat from animal sacrifices could have mixed with ashes from the fire and rain or a nearby river provided enough water to form a crude form of soap. The ancient Babylonians are given credit for using animal fats and wood ash to produce soap which was used primarily as a cleaning agent. Soap was not put to personal use for hygiene until many years later.

It was not until around 1840 that the Hungarian physician Ignaz Semmelweis recommended that physicians should wash their hands before and after a delivery to help prevent postpartum infections in their patients.

The accidental discovery of soap has resulted in some important health benefits as soap and water are capable of rendering microscopic pathogens inactive. Soap is an interesting molecule. One end has an affinity for water and is therefore hydrophilic. The other end of this skinny molecule avoids water and is hydrophobic and connects with oil and fats. This combination permits the molecule to float in water and form tiny bubbles called micelles.

Washing your hands allows the microbes to be surrounded by soap molecules which in turn begin to break the microbes apart. The hydrophobic tails wedge themselves into the lipid layers surrounding the virus or bacteria and pry the lipid walls apart. The inner proteins of the microbe then are washed away by water and the organism is then rendered useless or at least incomplete.

The coronavirus has a fatty membrane which can be attacked by soap and the subsequent wrecking bar effect of hand washing with soap kills the virus and water then washes the destroyed fragments away.

Hand sanitizers are not as effective as soap and should contain about 70% alcohol to be useful but they are a good backup if soap and water are not available. Some soap molecules destroy chemical bonds that allow microbes to stick to the skin and other surfaces.

Most viruses consist of three parts including RNA, proteins and lipids. These three do not have strong bonds holding them together and soap is their executioner. Skin, fabric and wood have rough surfaces to which the virus can readily attach. Smoother surfaces such as steel and plastic do not have the same adherence as skin. However, the virus can lay on the surface undisturbed for hours. The coronavirus is less stable in moisture, heat and sunlight. Fortunately, soap competes with the viral membrane and acts to dissolve the structures that hold the virus together.

Thanks to a recent New York Times article by Ferris Jabr and also an article by Palli Thordarson, a chemistry professor at New South Wales University in Sydney, for the above information. The simple act of good hand-washing with soap and water is essential in times like these. Twenty seconds of time with our new best friend of 5,000 years of age will ensure a healthy relationship!

David Keisler is a gastroenterologist and internist in Aiken.