Estimating the number of people that have died as a result of air pollution, or any type of pollution, isn’t the easiest task. Breathing in ultra-fine particulate matter and toxic gases can result in premature death, through respiratory or cardiovascular problems. Getting a clear cause-and-effect link, and quantifying that, is difficult.
Thankfully, scientists all over the world have worked on such estimates, and a new study – led by the Max Planck Institute for Chemistry in Mainz (MPI-C) and the London School of Hygiene & Tropical Medicine – has the latest. In 2015 alone, as many as 4.5 million people died prematurely from diseases linked to ambient (outdoor) air pollution, including 237,000 children below the age of five from respiratory afflictions. The findings are published in The Lancet: Planetary Health.
Before we go into the study itself, let’s put that 4.5 million number in context. That’s 12,329 people per day, on average. That’s like having just over four September 11 terrorist attacks every 24 hours. As another point of comparison, 1.3 million people die in road traffic accidents every year, which is 3.5 times fewer than those dying from ambient air pollution.
It’s a ludicrous figure, one that highlights just how much of a crisis this is. It neatly fits with another recent analysis by the World Health Organization (WHO), which estimates 4.2 million people die via ambient air pollution each year.
It’s largely about that particulate matter. It comes in all shapes and sizes when it emerges from smokestacks from power plants, agricultural activities, construction work, and vehicle exhaust pipes, but those smaller than 2.5 microns across – about 30 times finer than a human hair – are the real killers.
They’re so small that they easily get into your respiratory tract, and thereby kick up your odds of getting a whole host of illnesses, from heart attacks and strokes to lung cancer and obstructive pulmonary diseases.
That’s not all, of course. You’ve also got nitrogen dioxide, ozone, and sulfur dioxide, all of which can irritate and inflame the lining of your airways. So, with all this in mind, how did this new paper get to 4.5 million?
For this latest paper, the team took a multi-pronged approach. They used results from a complex computer model, one that simulated how chemicals move through the atmosphere. Health stats from the WHO were plugged in, and likelihoods of premature deaths due to air pollution – particularly due to afflictions of the lung – were calculated.
Remarkably, 4.5 million deaths isn’t even the most jaw-dropping figure.