Dr. Manal Mohammed, a microbiology expert at Westminster University in the UK, found E. coli on one in four pairs of shoes worn outdoors. Some strains of E. coli can cause life-threatening kidney problems. But the health risks people bring home on their shoes don’t stop there.
Some sealants used in construction and road repairs contain chemicals linked to cancer. Particles from those materials can be tracked into our homes. The study found that levels of those particles indoors can be up to 37 times higher when people bring them in on dirty shoes.
What else did the expert report?
In her report on the study, Dr. Mohammed stated, “Street shoes carry bacteria, allergens, and toxic chemicals, many of which are linked to serious health issues. Wearing outdoor shoes indoors is like inviting the street and everything on it into the most intimate corners of your home.”
She said shoes pick up harmful microbes and chemicals throughout the day from surfaces like bathroom floors, hospital corridors, and public walkways. That is particularly dangerous for small children, who often play and crawl on the floor.
Some strains of E. coli, which are found in the feces of animals and humans, can be extremely dangerous. They can cause bloody diarrhea and a potentially fatal kidney condition called hemolytic uremic syndrome.
Additionally, street shoes may carry Clostridium difficile, a bacterium that causes diarrhea, as well as Staphylococcus, a group of bacteria associated with skin infections, the Daily Mail reported.
Dr. Mohammed also warned about the danger of tracking in lead dust, a heavy metal that can disrupt brain development in young children.
She cautioned that allergens like pollen can cling to outdoor shoes and be brought into the home, which can make hay fever symptoms worse.
Dr. Mohammed urged people to leave shoes at the door after coming inside, saying this will “significantly reduce the exposure of harmful microbes and chemicals to your family.”
However, not everyone agrees with these warnings
Some scientists argue that wearing outdoor shoes at home can be beneficial, especially for children.
In 2019, researchers from Finland found that children who wore outdoor shoes at home were less likely to develop asthma. The researchers suggested that contact with different types of soil helped children build resilience to potential triggers.
These researchers say modern life is overly sterile. They and some colleagues argue that without early exposure to dirt and microbes, the immune system doesn’t learn to regulate its response to everyday irritants like dust and pollen, which could lead to health problems later. But the evidence for that theory is still debated.
