As the gas explosion last month in Farmington made clear, firefighters face on many calls the chance of sudden tragedy.

The biggest risks to firefighters, however, come on much more slowly.

For years, heart disease was the leading cause for death among firefighters, just as it is for the population as a whole.

However, for a couple of decades now, the No. 1 cause of death for firefighters has become cancer – and it is killing them at higher rates than everyone else.

What has changed? Homes and businesses are now filled with items made of plastic and other synthetic materials that not only burn faster and hotter than wood, but also give off toxic fumes. Firefighters not only take in those fumes and others, including diesel fumes from trucks, at the scene, they are also exposed to the remnants left on their gear.

Prolonged exposure to these toxins has been found in multiple studies to lead to an increased incidence in firefighters of a number of cancers.

The dangers of these fumes led the Legislature in 2017 to pass a law banning the sale of new furniture containing flame retardants, which have been found to be not only toxic when burned but also ineffective at slowing down fires.

The law came after a study found in firefighters levels of chemicals from flame retardants – linked to a whole host of health problems – that were two to three times higher than in the larger population.

That move may one day eliminate one source of toxins from fires as old furniture is discarded. But many sources remain.

Fire departments have taken steps to protect firefighters from ongoing exposure. Darcie Moore of the Times Record reported this week that Bath recently turned a storage area into a decontamination room where an extractor system cleans personal protective equipment of what one firefighter called the “toxic soup of chemicals” they encounter at a fire.

Best practices now have departments removing and packing gear at the scene to be rinsed later. Firefighters also should wipe themselves down at the scene, and it is recommended that they gear with breathing equipment on.

All departments should adopt these practices, and communities should support their acquisition of equipment designed to deal with contaminated gear.

Firefighters need to be protected, too, after they get sick. Most states now have on the books laws that recognize cancers found in firefighters while working or shortly after retirement as on-the-job injuries, making it easier for them to get workers’ compensation, disability benefits or death benefits for their families.

In Maine, the law covers firefighters who have worked for at least five years, regularly answered emergency calls, and are either within 10 years of active service or under the age of 70, whichever comes first.

But those laws haven’t always been enough, firefighters say. Stronger laws that are uniformly applied are necessary, they argue.

Under the Firefighter Cancer Registry Act, signed by President Trump last year, the federal government is collecting more information on cancer among firefighters.

The information should help it make clear the threats faced by firefighters most often come from doing their jobs, again and again, over years. And it should help convince lawmakers across the country to protect them and their families when something goes wrong.