Oliver Zhang wants one thing for Christmas: a home he can actually live in.

The IT professional, who's in his late 40s, suffers from environmental sensitivities so severe that he has had to move 70 times in the past three years.

"When the triggers come, I have to move again," he told CBC Toronto. "Your life's just totally destroyed."

His triggers are common indoor chemicals and the scents that many of us take for granted — carpet deodorizers, air fresheners and even paint.

Within two hours of exposure, he says, he's in unbearable pain — from stomach aches to tightness in the chest and lower pelvic discomfort — and must leave.

Even being inside a hospital is painful.

After a desperate search to find a home where he can live a healthier life, Zhang finds himself relying on community services for a place to stay. He has managed to find a mental-health crisis shelter in midtown Toronto that did not set off his symptoms.

Earlier this month, he had a sitdown meeting with administrators at the facility, who reluctantly agreed to let him sleep there on a temporary basis. As soon as all the beds are needed for people in crisis, he will have to go.

When that day comes, Zhang fears he'll have no choice but to live on the streets.

The strain of his fruitless search for a suitable, chemical-free home is plain in his demeanour. He speaks jerkily and is easily distracted.

"I almost do not have a life," he says. "I couldn't enjoy [time with] with my mother; taking good care of my kid . . . For the past three years, I couldn't take him indoor swimming, or see his indoor [piano] performances."

Dr. Lynn Marshall has been treating Zhang for just under a year. She says people with multiple chemical sensitivities/environmental sensitivities can recover with prolonged protection from the airborne chemicals that trigger their illness. (Richard Agecoutay/CBC)

Zhang's disorder is known to the medical community as multiple chemical sensitivities/environmental sensitivities (MCS/ES).

The Environmental Health Clinic at Women's College Hospital in Toronto specializes in treating people with the disorder. But those treatments are limited, according to Dr. Lynn Marshall, who has been seeing Zhang for just under a year.

"As well as the patient being very frustrated, I as a doctor am very frustrated too," she said. "He had tears in his eyes because he couldn't go anywhere with his son. I can't help that."

So how do you treat someone with MCS/ES?

"Teach him how to avoid the things that really trigger his symptoms," she says, because that's the first step toward recovery. But it can be a long road, she says. "We can't say how long it will take any individual."

Zhang's condition is so severe that he needs to wear an air filter just to take public transportation. (Oliver Zhang)

Meanwhile, Marshall says the problem seems to be growing.

She works a limited amount of time at the WCH clinic, but she's seen increases in her workload in recent years.

"Our waiting list is over a year," she says. "I hate that. But that's what it is ... So many people requiring assistance, requiring diagnosis."

Marshall points to federal statistics that show 800,500 people were diagnosed with MCS country-wide in 2010, up by 13.5 per cent from 2005.

In Ontario alone, there were 292,700 people diagnosed with MCS by a health care professional in 2010, she says.

This province's Ministry of Health and Long-Term Care launched a task force on environmental health in 2016. Its job is to find new ways to treat people with MCS/ES.

Results expected in 2019

The ministry wouldn't speak with CBC Toronto, but in an emailed statement, ministry spokesperson David Jensen said:

"Phase 2 of the task force, now underway, will consist of developing a set of recommendations for a system of care for people with Multiple Chemical Sensitivities /Environmental Sensitivities as well as for research, and both professional and public education. The government looks forward to receiving the report in 2019."

In Quebec, where more than 180,000 people live with the condition, sufferers aren't waiting for help from their provincial government.

An artist's rendition of a housing project being developed in Quebec specifically for people with MCS/ES. It will eventually house 40 families in the Laurentian Mountains. (Ecoasis)

The Environmental Health Association of Quebec (EHAQ) is in the midst of establishing a colony in the Laurentian mountains north of Montreal specifically for sufferers of MCS/ES.

It's called Ecoasis and will include four structures, each of which will contain 10 affordable housing units. Ultimately, 40 families will live there, according to EHAQ founder Rohini Peris.

It's part of a larger parcel of land that was donated to the group for a housing project.

Visitors will be screened before entry

Each unit will be specifically designed to include none of the most common triggers that affect people with MCS/ES.

Visitors will be screened to ensure that the housing project isn't contaminated with some of the most widespread triggers, such as perfumes or cigarette smoke.

Peris suffered from MCS/ES for more than 20 years.

Her condition eventually subsided in 2016 after she and her family were careful to eliminate as many chemicals and other stressors from her living environment.

Rohini Peris suffered from MCS/ES for more than 20 years, prompting her to help found a housing project in Quebec for sufferers. (Jean-Claude Taliana/CBC)

"I don't have it anymore, but my biggest concern is that I don't know what I'm going to walk into when I walk into a mall. I don't know what chemicals are present," Peris said.

"This happened to me one time. It could happen again."

Recovery will likely also be the outcome for Zhang, Marshall says.

But until then, Zhang's hunt for a home continues while he lives on disability payments from his former job.

He's worried his time at the mental-health crisis shelter may be ending soon, and about where his next stop might be.

"Winter is coming," Zhang said.