How Did Canaries Help Coal Miners?
How did canaries help coal miners? There was a time when coal miners wouldn’t set foot in a coal mine without a canary present. Canaries protected them from a danger that lurks in the mines—carbon monoxide (CO). This is an odorless, toxic gas. CO can cause dizziness, loss of consciousness, and even death in humans and animals.
What made canaries so well-suited to protect miners from carbon monoxide? Their breath is more rapid than that of most humans, causing them to take in more air. If poisonous gas was in the air, canaries would breathe in twice as much of it, causing them to become sick before the miners did. If a coal miner saw that a canary was acting strangely, they knew to leave the mine at once.
Why would they take canaries into coal mines? The practice of bringing canaries into coal mines began in 1911 and took off quickly. In many cases, miners came to see the canaries as both protectors and pets. As such, they came up with ways to protect their companions, as well. One example is a device designed to resuscitate canaries who lost consciousness due to poisonous gas. When activated, it provided the birds with increased oxygen, often saving their lives.
The canaries weren’t the only animals to help protect coal miners from poisonous gases. Mice also did the job for a time until miners realized canaries gave an earlier warning. Today, digital CO detectors are used instead of the animals that warn miners of danger.
The idea of using canaries is credited to John Scott Haldane. Known to some as “the father of oxygen therapy.” His research on carbon monoxide led him to recommend using the birds. He suggested using a sentinel species: an animal more sensitive to the colorless, odorless carbon monoxide and other poisonous gases than humans. If the animal became ill or died, that would give miners a warning to evacuate.
Why was a canary Haldane’s suggested solution? The canaries, like other birds, are good early detectors of carbon monoxide because they’re vulnerable to airborne poisons. Because they need such immense quantities of oxygen to enable them to fly and fly to heights that would make people altitude sick.
Their anatomy allows them to get a dose of oxygen when they inhale and another when they exhale, by holding air in extra sacs. Relative to mice or other easily transportable animals that could have been carried in by the miners. They get a double dose of air and any poisons the air might contain, so miners would get an earlier warning.
The use of canaries in coal mines ended on December 30, 1986. New plans from the government declared that the “electronic nose,” a detector with a digital reading, would replace the birds, according to the BBC. However, you may still hear people use the phrase “canary in a coal mine” today. It’s an advanced warning of some danger. The metaphor originates from the times when coal miners used to carry caged canaries while at work; if there was any methane or carbon monoxide in the mine, the canary would die before the levels of the gas reached those hazardous to humans.