Dozens of groups are pressing Ottawa to join more than 50 countries in banning asbestos, a move the Liberal Party supported while in opposition.

A letter sent to Prime Minister Justin Trudeau this month notes that Canada still allows the use of asbestos and lacks a comprehensive strategy to phase out the substance or to promote safe substitutes.

Separately, the Canadian Cancer Society has also sent a letter to the government, a copy of which was given to The Globe and Mail, calling for a nationwide ban on all asbestos products, a rare step for the country's largest national health charity.

"It's time to send a clear message and establish clear policy to end asbestos, end any confusion about its dangers, any confusion about the toll it's taken, and any debate there is about a mythical 'safe' exposure level, and most importantly, [end] the exposure of Canadian workers and families to this potentially deadly substance," said Gabriel Miller, director of public issues at the Canadian Cancer Society.

In an e-mailed statement, Health Canada said it will carefully consider whether further controls of asbestos are necessary, in addition to the measures the government has in place to protect Canadians from exposure.

Adding to a sense of urgency is the federal government's plans to boost spending on infrastructure. Those plans raise concerns that asbestos in pipes, cement or other building materials could wind up in new construction.

"Given the huge investment that the federal government is going to make around infrastructure, this is the time to say 'we're not going to repeat past mistakes,' " said Hassan Yussuff, president of the Canadian Labour Congress, the county's largest labour organization, which is also calling for a comprehensive ban on asbestos.

Backed by nurses' associations, building trades councils, unions and some city councils, the letter to the Prime Minister makes 11 recommendations, among them: passing legislation that bans the use of asbestos; prohibiting the use of asbestos-containing materials in federal infrastructure projects; and ensuring safer disposal and creating a national registry of asbestos exposure locations and diseases. It also wants to see a broad public-health response to asbestos diseases.

The World Health Organization says all types of asbestos cause lung cancer, mesothelioma and other types of cancers along with asbestosis. It says the most efficient way to eliminate these diseases is to stop the use of asbestos.

But Statistics Canada trade data show asbestos-related imports rose to a six-year high last year – $8.3-million in 2015 from $6-million a year earlier. About half of that was in brake pads and linings, while this country also imported raw asbestos, sheets and pipes, clothing and fabricated products. Exports have markedly declined, but Canada still exported $1.2-million to other countries in clothing, building materials and fabricated products.

Asbestos is the top on-the-job killer in Canada. New cases of mesothelioma – a cancer caused almost exclusively by asbestos exposure – have more than doubled in the past two decades. Each year, more than 2,000 people are diagnosed with asbestos cancers and other diseases, according to Cancer Care Ontario. About 150,000 Canadian workers are exposed to asbestos in their workplaces, Carex Canada estimates, among them construction workers and contractors, mechanics, shipbuilders and engineers.

Canada was once one of the world's top producers of asbestos, and shut its last mine in 2011. The federal government in the past had defended the industry and maintained a position of "safe and controlled use," a stand that was harshly criticized by doctors, scientists, advocates and those who have been affected by asbestos-related diseases. Countries including Australia, Germany and Britain have banned the mineral.

In an interview a year ago, Liberal MP Geoff Regan – now Speaker of the House – told The Globe and Mail he speaks for the party in favouring a ban of all asbestos use in Canada.

That's what Renée Guay is hoping to see soon. She watched her father pass away in "unbearable" pain in 2011 from mesothelioma at age 59. He was exposed at a manufacturing plant in St. Catharines, Ont., where he worked as an engineer. Her uncle, who worked in the same facility, was diagnosed with asbestosis last year.

"It's discouraging … and it just goes back to that Canada doesn't have a plan, and how is this okay? We've known this is an issue for years, and no one's doing anything. It doesn't make any sense."

The number of new mesothelioma cases rose to a record 580 in 2013, according to Statscan. Mesothelioma has a long latency period, of 10 to 50 years, and researchers expect new cases will continue to climb.

"There is no sign that we have reached the peak," said Paul Demers, director at the Occupational Cancer Research Centre, who estimates that about 80 per cent of these cancers stemmed from workplace exposure to asbestos, and almost all of the rest "due to exposure at home from the clothes of a family member who worked with asbestos" or through other forms of environmental exposure.

His team's analysis, based on studies of exposed workers, pegs the number of lung cancers attributable to occupational asbestos exposure at about 2,000 in 2013.

"This government stated clearly when they got elected, they're going to be relying on science-based decisions, and there's no question that the WHO and even now Health Canada have come to realize that asbestos is a carcinogen," said Mr. Yussuff, himself exposed to asbestos dust when he worked at a General Motors truck plant, and wonders about the impact that has had on his health. Given the body of evidence. "I hope the government will do the right thing, because knowing that fact, why would you allow this substance to be imported, and why would you allow Canadians to be exposed to it?"

Asbestos was the most common source in workplace death claims in 2014, cited in 388 cases, most-recent data from the Association of Workers' Compensation Boards of Canada show. In that year, mesothelioma was the No. 1 cause of death in accepted fatality claims.

"When you look at the No. 1 [occupational] disease that people are going to die from, asbestos is right up there," said Dr. Andréane Chénier, national health and safety specialist with the Canadian Union of Public Employees. Hundreds of people are dying from asbestos-related diseases every year, "and you know this is going to be a very slow, very painful death. It's heart wrenching to watch, and there's no cure. But it's preventable – we know this stuff is bad."

"There is no safe use. People keep saying oh no, there are safe ways to use it – no there aren't. There aren't because it's not fibres you can see, it's the fibres you can't see."

In Ottawa, Michaela Keyserlingk says she's tired of waiting. "I'm deeply disappointed" no action has been taken, said Ms. Keyserlingk, whose husband of 47 years died in 2009 of mesothelioma, after exposure as a cadet in the Canadian navy. "We lived this perfect life. And then suddenly, my husband who ran marathons and played tennis couldn't get enough air … he survived [with mesothelioma] for the next 2 1/2 years. This cancer and lack of oxygen, he had real anxiety attacks … he was skin and bones. I terribly miss not being able to talk to him."

"I had thought when the Liberals were elected I could now relax and think everything would be in good hands. And I'm not convinced any longer that this is the case."