Tetsuo Yanagida has said for years that he suffers from a little-known ailment known as multiple chemical sensitivity, a condition in which those afflicted experience breathing difficulties and other symptoms after exposure to chemicals in the surrounding human environment.

Two decades later, he now renovates residential properties using chemical-free building materials to provide homes for people who suffer from the malady.

"My hope is to help people who can't even take in a deep breath at home or have given up on living a normal life," said Yanagida, 47, from Nishinomiya, Hyogo Prefecture, in western Japan.

Tetsuo Yanagida (L) and a vendor discuss special wallpaper for sufferers of multiple chemical sensitivity at a property undergoing renovation in Kobe in March 2023. (Kyodo)

People who suffer from MCS can react to synthetic substances like detergents and paints, among other chemicals, causing various symptoms, including headaches, nausea, dizziness, body aches and breathing difficulties.

According to a MCS support center, a certified nonprofit organization based in Yokohama, more than 1 million people in Japan suffer from the illness triggered through exposure to even small amounts of the causative agents.

Despite that figure, debate continues in the medical community about whether MCS sufferers' symptoms are actually caused by exposure to chemicals, and if the condition can be classified as an illness.

The World Health Organization does not list it on its International Classification of Diseases and Johns Hopkins University in the United States says many medical professionals "lean towards these symptoms being physical manifestations of psychiatric illness rather than a primary medical illness."

Perhaps due to this, few doctors in Japan diagnose the condition and many patients suffer in silence. Some with severe symptoms are forced to move from home to home and cannot work.

Yanagida began to experience breathing difficulties and other MCS symptoms after moving into a wooden apartment when he worked in Tokyo in 2002. He believes it was caused by pesticides sprayed under the floorboards. Despite efforts to ventilate the space, he could not bear the discomfort and moved out within a week.

Tetsuo Yanagida, who renovates residential properties for sufferers of multiple chemical sensitivity, is pictured in Kobe in March 2023. (Kyodo)

Afterward, he changed jobs and returned to his hometown in Hyogo, but Yanagida continued to experience headaches, dizziness and other symptoms at work. In 2018, he went from holding down a full-time job to becoming a contract employee, which enabled him to work from home.

Thinking that "there must be many people who suffer like me," Yanagida sensed a lack of living spaces for people hypersensitive to chemicals and embarked on a side business the same year to make available chemical-free rental properties.

He searches for properties to purchase and refurbish with good ventilation and at comparatively high elevations, mainly in the Kansai region in western Japan.

Usually, the walls and ceilings of rental properties in Japan must be repapered once a new tenant has been approved. To work fast, thick wallpaper is frequently used with plasticizers containing chemicals that make walls more pliable.

Yanagida uses a special wallpaper underlaid with aluminum sheets to prevent the vaporization of harmful volatile organic compounds in the walls. The product is sold by Pajaro Campana, a Kyoto-based company formed by MCS patients who act as intermediaries for tenants looking for chemical-free housing.

The company researches and develops safe housing products to prevent "sick building syndrome" and related illnesses, it says.

"People who can empathize with other peoples' suffering help each other out," said Yanagida, who is renovating two rooms in an apartment complex in Kobe, western Japan, where he started work this year.

He had previously hired a building contractor, but "they keep messing things up since they don't understand the seriousness of the situation."

In addition to the advantage of keeping rents low by working together with Pajaro Campana, Yanagida has received favorable feedback from tenants who feel "at ease" because they can check every corner of their rooms before moving in.

The MCS support center receives roughly 2,000 inquiries yearly, many related to housing choices. "While symptoms may differ depending on the person, the housing environment is a serious issue that all the patients face," said a center official.

All the properties on which Yanagida works are located in apartment complexes, which means people still can develop symptoms from scents such as fabric softeners or air fresheners that might drift from neighboring apartments.

"In the future, we would like to make all the rooms in our housing complexes chemical-free with specifications against bringing in such substances, and create a community where people can live comfortably even if they have this illness," Yanagida said.