News Genkan lockers as ‘dirty’ as bathroom drains

[thomas]

If you've ever wondered which places were the most contaminated in your home - in terms of mould - it would be your bathroom drain - and leather footwear stored in Japanese "genkan" lockers, according to Nobuo Hamada, a visiting researcher at the Osaka Museum of Natural History.

Photo credit: Nobuo Hamada, a visiting researcher at the Osaka Museum of Natural History​

Researchers found that a buildup of fungi inside the front of shoes during the high humidity of a Japanese summer is a particular health hazard. [...] Hamada has been looking at how air conditioners, bathrooms and washing machines are breeding grounds for mold as part of efforts to create cleaner living spaces. He embarked on the study after realizing that little data existed on the types of fungi infestations in shoes. His only guide was research that focused on a variant known as Trichophyton that is responsible for athlete's foot. For that reason, Hamada and his colleagues examined the footwear of 74 individuals this past summer to assess the extent of the problem that is endemic to households across Japan. Specimens per unit area were collected and swabs taken from various areas of each shoe. The samples were then cultivated for six to eight days at 25 degrees to determine mold spore numbers and types. The findings showed that the area of tiptoes are the most polluted with a staggering 36,497 mold spores per square centimeter. This is comparable to the contamination level of bathroom drains, which are considered the dirtiest area of any household. Samples also showed that the areas under the toes generate an average of 24,363 spores per square cm while the inner and outer areas of the sides of shoes recorded readings of 45 and 113, respectively. The central areas inside shoes produced a reading of 38 spores per square cm and the back portion was marked by 24.

Men's shoes are more likely to contain mould: an average of 453 spores were from men's shoes. Shoes worn by women averaged 83. Individuals aged 24 or younger had 16 on average, compared with 343 among those between the ages of 25 and 60. For those aged 60 and over, the number came to 2,025, underlining a tendency for older people to have more spores in their shoes.

Footwear infested with mold as ‘dirty’ as bathroom drain | The Asahi Shimbun: Breaking News, Japan News and Analysis