Colorful walls can 'blow away' toilet odor, Japanese study says

by Sarah Suk

Staff Writer

Using bathrooms can be an everyday nightmare for children attending Japan’s public schools where the restroom is often considered dirty and smelly.

But a professor in western Japan has come up with an eye-opening way to blow away the stench.

Machiko Yamashita, a professor of environmental life studies at Otemae University, conducted a seven-year research project in which she and her students repainted the walls of 200 restrooms at 21 public elementary and junior high schools in Nishinomiya and Amagasaki, both in Hyogo Prefecture, in several variations of red, blue, green and orange.

During the project, which began in 2009, she handed out a multiple-choice questionnaire to about 6,800 students in total at the schools where the painting project took place, asking whether they felt the lavatories to be warmer or colder, bigger or smaller, brighter or darker, and whether or not they felt differently about the odor and cleanliness of the toilets.

While many of the responses were within expectations from the perspective of color psychology, there were some aberrations. In particular, results showed that roughly a quarter of the students on average said they felt the smell diminished after the wall color changed.

“It was interesting that the response was not zero percent even though the odor obviously hadn’t lessened,” Yamashita told The Japan Times by phone. “That confirmed that there is a relationship between color and smell in human perception.”

Bathrooms at public schools in Japan often have similar-looking walls with dull-colored tiles and light grayish paint, and a majority of them have not been renovated since the 1960s, the professor explained.

“Children don’t want to use such toilets at schools. The bathroom in their homes are probably clean and comfortable, but bathrooms at school are old and horrible,” she said.

Junko Kobayashi, an architect who runs Tokyo-based Gondola Design Office which specializes in creating restrooms that are comfortable to use, concurred.

“It’s been about 30 years since reforms of toilets began in Japan,” Kobayashi said. “Those at department stores, in particular, have been renovated and they are getting cleaner and cleaner. Restrooms at transportation facilities and commercial buildings are also becoming clean, but school bathrooms, unfortunately, haven’t changed.”

She said there are a few public schools that have modernized their restrooms but that most have toilets that are 30 to 40 years old and quite dirty, and renovating all of them would take considerable time and money.

In contrast, private schools are putting a lot of effort into making their bathrooms clean so they can attract more students as numbers of applicants fall due to the declining birthrate, Kobayashi said.

Otemae University’s Yamashita, whose research themes include color and environmental psychology, said more than 60 percent of schools across Japan still have old restrooms.

“The restroom is deeply connected with autonomic nerves. They say autonomic nerves could be disturbed biologically when people use dirty bathrooms. I focused on lavatories in my research for the sake of children’s health,” she said.

“We weren’t able to replace tiles or paint over stone or metal parts, but we could paint the walls and wooden areas. I chose colors that can make the existing tiles look bright,” she added.

Schools were at first reluctant to try something new, but Yamashita was able to get one school involved with the cooperation of Nishinomiya city hall. The project then gradually spread to 20 more schools, one of them in adjacent Amagasaki. Nishinomiya has a total of about 60 public elementary and junior high schools.

With the help of her students, who painted the bathroom walls after classes were over, and guidance from a painting and decorating company, Yamashita made the colors work their magic.

“It was a case of killing three birds with one stone because I was able to accumulate experimental cases for my research, we reformed the environment of schoolchildren and made them happy, and my students were able to make social contributions and grow,” she said.

To confirm her findings based on these real examples, she also carried out a virtual experiment in parallel for four years, having university students respond to the same questions using a simulation with monitors that displayed images of a bathroom before and after its walls were painted. The results were largely similar.

“There’s no way the smell could change just by looking at the screen, but some respondents said they felt the odor decreased. That was fascinating,” Yamashita said.

She compiled the results of this research project into a book published last year, including in it a guide for other schools to paint their bathroom walls, with suggestions of which colors are effective depending on the base color of the tiles.

As part of her research, Yamashita also traveled to London, Amsterdam and Copenhagen four years ago to survey the bathrooms of a total of 60 public elementary schools. She was impressed by the abundant use of color there.

“The bathrooms were colorful. Not all of them were clean but, on the whole, they were made so children could feel comfortable using them,” she said.

“Some had different colors depending on grade or floor, but I was most impressed that at many schools the door of each toilet stall had colors that stood out. In Japan, the doors are almost the same color as the surroundings, but especially for small children the color on the door can help lead them to the toilet,” she noted.

Yamashita has recently resumed painting bathroom walls at some schools in Nishinomiya, but this time it’s not for her research.

“We didn’t paint the walls of restrooms for faculty and staff during the study project because we were busy trying to obtain data from school children, not adults, back then. So now I’m thinking about making the remaining bathrooms look modern and fashionable,” she said.

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