In the past, most people believed that the toilet in the bathroom and the cutting board in the kitchen were the dirtiest places in the house. However, scientists now point out that everyday items in households are much dirtier than toilet seats. They suggest that regular cleaning of these everyday items is essential to suppress the growth of bacteria and mold, reducing health risks.
A study has revealed that seemingly harmless sofas are actually the dirtiest spots in homes. Researchers from one of the UK government-approved testing laboratories, Melbec Microbiology, along with the Sofa Club, wiped six sofas from different UK households to test the amount of hidden bacteria.
They found that on average, every 100 square centimeters of a sofa contains about 509,000 aerobic mesophilic bacteria (AMB), which are typically associated with dead skin and food particles. In comparison, toilet seats only have about 6,800 AMB per 100 square centimeters, and kitchen trash bins around 6,000 AMB.
The dirtiest sofa belonged to a household with two cats, harboring over a million Escherichia coli bacteria per 100 square centimeters. The second dirtiest sofa belonged to a couple with dogs, with an average of 193,000 colony-forming units (CFU) per 100 square centimeters, even though they claimed to clean the sofa monthly. The sofa of a single adult contains an average of 46,000 CFU per 100 square centimeters, still six times dirtier than a toilet seat.
Researchers also found yeast, mold, coagulase-positive Staphylococcus, and Escherichia coli on sofas. The presence of yeast and mold may affect asthma patients or individuals with weaker immune systems, while coagulase-positive Staphylococcus and Escherichia coli could lead to food poisoning, sepsis, and Staphylococcus infections.
To understand other potential sources of bacteria, researchers also examined other household items. It was found that desks have 5,900 AMB per 100 square centimeters, slightly cleaner than trash bins; laptops have around 5,800 AMB, TV remote controls have 3,700 AMB, and doorknobs have 1,800 AMB.
Monika Puccio, an interior expert at the Sofa Club, told the UK’s Daily Mail, “Aside from our beds where we sleep, sofas are the second most-used furniture in homes. The bacterial content of sofas can be influenced by various behaviors, including eating on the sofa, napping, or allowing pets on the sofa. Many people clean their bedding weekly but overlook sofa cleaning.”
Puccio recommended, “Wiping down the sofa daily can prevent stains and the accumulation of daily dirt. For deep cleaning, sprinkle baking soda (note the material) on the sofa, let it sit for 20 to 30 minutes, then remove it.”
Puccio also advised that cushion covers should be washed according to the laundry label, dried, and then placed back on the sofa. She added, “Your sofa may be the dirtiest seat in the house, but the good news is, with some simple cleaning habits and consistent effort, you can eliminate bacteria to keep the sofa clean and free of dirt.”
Apart from these everyday items, experts warned that headphones, computer mice, keyboards, and phones also harbor a large amount of bacteria.
CloudZero, a cloud cost optimization platform and software company, conducted a study on the bacterial quantities present on daily consumer electronics (3C). Researcher Cody Slingerland shared the survey results and cleaning guidelines on a blog.
Slingerland mentioned in the article that gadgets such as phones are often taken to public places, beds, or restrooms, leading to possible contamination by bacteria such as Staphylococcus, Bacillus, Pseudomonas, and mold.
On average, phones carry 1,073 colony-forming units of bacteria, laptops 645, mice 408, keyboards 237, and headphones 186. Headphones can sometimes have over 3,000 bacteria due to the warm, moist environment of the ears, along with sweat and dirt left during physical activities, providing a perfect breeding ground for bacteria.
The amount of bacteria on laptops is related to how they are used. If food is frequently consumed near the device or if it is not cleaned regularly, it can harbor a significant amount of bacteria and mold, which could affect one’s health.
The bacteria quantities on mice and keyboards are linked to laptops and also require regular cleaning to prevent these items from becoming breeding grounds for microorganisms.
Although phones may have fewer detectable bacteria, they are likely to transfer bacteria to the skin and interior body during use, suggesting the need for regular cleaning. Many studies have shown that the bacterial levels on phones that are not regularly cleaned can be more than ten times higher than on toilet seats.
Slingerland provided recommendations and cleaning guidelines in the blog. Firstly, turn off the device to avoid damage during cleaning; use cleaning agents or alcohol that do not harm the device, spray on a soft cloth, then wipe the product’s surface with it.
Keyboards can be cleaned with air guns or vacuum cleaners to remove debris and dirt from crevices. For surface dirt, cleaning can be done using the methods mentioned. Phones should have their cases removed, surfaces and crevices wiped, and the case cleaned and dried afterward.
Dr. Maria Knobel, Medical Director at Medical Cert UK, expressed to Slingerland saying, “To reduce the risk of infections like colds, the flu, or acne, these devices should be cleaned using a soft, safe disinfectant to remove harmful dirt, effectively reducing or preventing the spread of germs.”