Bacteria on the Skin and Why We Should Wash Our Hands
Bacteria in Our Environment
All day long our hands touch different objects. These objects are usually covered by microscopic bacteria. The bacteria contaminate our hands and enter our body when we touch our nose or mouth. Many of the microbes are harmless, but some are dangerous. Our immune system is often able to destroy the harmful bacteria. Sometimes, however, the immune system is overwhelmed by the microbial invaders and we become ill.
Since it's hard to avoid potentially harmful microbes in the environment, it's important that we wash our hands regularly. This is especially true when performing an activity that has a high chance of bacterial transfer—such as using a washroom—or after touching an object that's likely to have dangerous microorganisms on its surface.
Hand washing is considered to be a very important aspect of hygiene. An international coalition of government, scientific, and private organizations has held a Global Handwashing Day on October 15th of every year since 2008.
Fecal Contamination of Hands
Fecal bacteria can be transferred from one person to another by unhygienic washroom procedures. Bacteria can also be transferred from a person's rectum to another part of their body by lack of hygiene. To many people, washing their hands after using a washroom is an automatic activity that they would never consider omitting. Research has shown that a surprising number of people don't wash their hands after using a toilet, however.
In a UK research project, electronic recording devices in gas station washrooms provided interesting and scary data. Although 99% of the people interviewed said that they had washed their hands after using the washrooms, the recording devices showed that only 64% of the women and 32% of the men had actually turned on the faucet to wash their hands.
Fairly similar results were discovered at three Minnesota state fairs. Observers recorded hand washing in male and female washrooms. The percentage of hand washers at the three fairs were 64%, 65% and 75% for females and 30%, 39% and 51% for males.
Some researchers acknowledge that they need to do more specific research to study hand washing percentages after urination compared to those after defecation. Some also want to determine if the assumption that hand washing after urination is less important for males than for females is actually valid.
Many experts suggest turning off the faucet in a public washroom with a paper towel instead of with a hand. Some suggest using the towel to open the door before leaving the washroom and discarding the towel after this is done. Another common suggestion is to use an elbow instead of a hand to press the handle of a paper towel dispenser. An ideal washroom has a no-touch toilet flush, no-touch faucets, and a no-touch hand dryer, but not all washrooms are ideal.
It's a good idea to stay as far away from a toilet as possible as it flushes. The spray created by the flush contains bacteria.
Fecal Contamination of Other Items
Fecal bacteria are definitely being transferred out of washrooms. In one study, hygiene experts in the UK discovered that 26% of the tested hands were contaminated with fecal material and 11% were grossly contaminated. The researchers also found that 14% of paper money and 10% of credit cards in their sample were contaminated with fecal matter.
Earlier research found that one in six cell phones were contaminated with fecal matter containing strains of E. coli that are known to be associated with severe stomach cramps, nausea, vomiting, and diarrhea.
A 2014 study by researchers at New York University found DNA from 3,000 bacterial species on dollar bills.
What Items Have the Most Bacteria on Their Surface?
Almost any item has bacteria on its surface, unless it has been sterilized and kept in a sterile environment. However, certain objects are more likely to contaminate our skin than others.
There are many situations in which our hands can pick up possibly dangerous bacteria. Hygiene procedures while using a toilet and touching the toilet parts are major sources of fecal contamination on the hands. Other ways to pick up microbes include touching objects such as:
- door handles and knobs
- faucet handles
- shopping cart handles
- handles of paper towel dispensers in washrooms
- railings and the handrails of escalators
- elevator buttons
- telephones and cell phones
- paper money and coins
- grocery and credit cards
- computer keyboards
- light switches
- kitchen sinks
- items contaminated by nasal discharge, saliva, vomit, animal or human waste, or soil
- contaminated food and water
Harmful bacteria may also be found on kitchen countertops, in refrigerators, and on work desks.
Does Hand Washing Remove Bacteria?
Researchers at the London School of Hygiene and Tropical Medicine tested whether hand washing with plain water or with soap and water could destroy bacteria that came from feces. Volunteers touched door handles and railings in public places. Their hands were then tested for the presence of bacteria. This procedure was followed multiple times with each of the twenty volunteers.
44% of the samples showed the presence of Enterococcus and Enterobacter, two microbes that are often found in feces and can cause diarrhea. Washing the hands with water alone reduced the percentage of samples with the two kinds of bacteria to 23%. Washing the hands with water and plain soap reduced the samples with bacteria to 8%.
How to Remove Germs in Hand Washing
Some people may think it's strange to be told how to wash their hands, since they've been doing it all their lives and it seems like a very simple activity. Hygiene experts are serious in their attempts to get us to wash our hands in the best possible way to kill bacteria and other germs, however.
All parts of the hand have to be cleaned—the palm, the back, and the fingers. We need to pay special attention to the fingertips and to the area under the fingernails and between the fingers. Rubbing the hands together is very important. Experts also say that we need to wash for at least fifteen to twenty seconds, not counting the rinsing. Two suggestions are to sing "Happy Birthday to You" twice, or "Twinkle, Twinkle, Little Star" once (aloud or in our mind) as we're washing. This could be a fun way to teach children to wash their hands correctly, but it's not a bad idea for adults either.
Plain soap doesn't kill germs, but it does help to remove them from the skin. Soapy water removes both dirt and oil from skin. The friction created by rubbing the hands together while washing with soap is also an important mechanism for removing grime and bacteria.
The Best Type of Soap
Researchers recommend plain soap over antibacterial soap. Antibacterial soap does kill some bacteria, but it needs to be left on the skin for longer than plain soap in order to have a significant effect. A two minute exposure is necessary, according to the Minnesota Department of Health. They say that plain soap is sufficient and that antibacterial soap isn't necessary. Some researchers are concerned that the use of antibacterial soaps is increasing the resistance of bacteria to chemicals that are designed to kill them.
Liquid soap is sometimes recommended over bar soap, since a microbe population is more likely to build up on a bar of soap. It's important to keep the liquid soap covered to prevent or reduce the entry of bacteria, however.
Do Hand Sanitizers Work?
Hygiene experts say that alcohol-based hand sanitizers do kill germs on the hands, provided they contain at least 60% alcohol. They don't work on hands that are visibly dirty, though. The hands should be washed with soap and water to remove grime so that the hand sanitizer can do its job. Health agencies recommend that we carry a small container of sanitizer with us to use when soap and water aren't available. Some supermarkets and other public buildings provide hand sanitizer stations for the public.
How to Wash Your Hands and Use Hand Sanitizer
A Hand Washing Poll
Do you use hand sanitizer?
How to Reduce Bacterial Infection
Hygiene is very important to prevent the spread of disease. Many of us are well protected by our immune system, but we still need to be careful in high-risk situations. The body's defensive mechanisms may need some help under these conditions. This is a good reason for maintaining a healthy immune system.
Since bacteria are too small for us to see or identify, we never know if something that we touched was contaminated by harmful organisms. Our bodies can usually deal with small numbers of these creatures. In some situations there are likely to be large numbers of potentially dangerous bacteria present, however.
The most important hygiene procedures are to wash the hands before and after certain activities. We should wash our hands before handling food, before eating, before applying a cosmetic or a first aid treatment to the skin, and before putting contact lenses in the eyes. We should also wash our hands after the following activities:
- using a toilet
- doing housework
- doing messy chores
- collecting or putting out garbage
- touching or cleaning up human or animal feces
- cleaning pet cages and litter trays
- touching animals (in some situations)
- touching liquid discharges from the body
Another helpful step to reduce infection is to get out of the habit of touching our nose, mouth, or eyes during the day, unless this is necessary. It's also a good idea to increase the amount of hand washing when a bacterial infection (or an infection by a fungus or a virus) is spreading through our community or home.
Hygiene and Pets
Some health experts say that we should wash our hands with soap and water after touching pets. This is impractical for me, however. I stroke or touch my dogs and cats repeatedly throughout the day. It is an important safety procedure for young children with immature immune systems, however, especially as they frequently put their hands in their mouths. It's also important after touching animals in petting zoos.
I do wash my hands after playing a fetch game with my dog, since his saliva and dirt collect on his toys. I also wash my hands after touching a pet outside the family because I don't want to spread germs to my own pets. In addition, I wash after high-risk situations such as clearing up pet urine or feces. This works well for me.
Maintaining Hand Hygiene Without Excessive Washing
Despite the fact that we're picking up bacteria on our hands all the time, we don't need to become obsessive about hand washing. We certainly don't need to use a hand sanitizer every few minutes. After all, we're constantly touching objects that have been touched by other people, yet most of us are not constantly getting sick. People working in certain jobs, such as in a medical field or in food preparation, do need to wash their hands more frequently than other people, though, and so do people with impaired immune systems.
Experts say that we should be careful but not fearful with respect to hand hygiene. We should wash our hands thoroughly in high-risk situations, follow a safety routine when using a public washroom, use a hand sanitizer when we need to wash our hands but can't get to a sink, and follow the recommendation of health agencies to wash our hands more often during the outbreak of a disease in our family or in our community.
References and Resources
- The Global Hand Washing Partnership
- Hand Hygiene Recommendations from the Minnesota Department of Public Health
- Hand Washing in Britain from the BBC (British Broadcasting Corporation)
- E. coli on Cell Phones from the CBC (Canadian Broadcasting Corporation)
- Bacteria on Dollar Bills from the Wall Street Journal
- Burton M, Cobb E, Donachie P, Judah G, Curtis V, Schmidt W-P. The Effect of Handwashing with Water or Soap on Bacterial Contamination of Hands. International Journal of Environmental Research and Public Health. 2011;8(1):97-104. doi:10.3390/ijerph8010097
Questions & Answers
© 2012 Linda Crampton