The threat of pollution grabs our attention once we see it — for instance, the tendrils of the smoke of Australian brush fires, now visible from space, or the poisonous soup of smog that descends on cities like New Delhi within the winter.

But polluted air also harms billions of individuals on an unbroken basis. Outdoors, we inhale toxins delivered by automobile traffic, coal-fired plants and oil refineries. Indoor fires for warmth and cooking taint the air for billions of individuals in poor countries.

Airborne toxins damage us during a staggering number of the way. alongside well-established links to carcinoma and heart condition, researchers are now finding new connections to disorders like diabetes and Alzheimer’s disease.

Scientists are still deciding how pollution causes these ailments. they're also puzzling over the apparent resilience that some people need to this contemporary onslaught.

Some researchers now argue that the answers to those questions dwell our distant evolutionary past, many years before the primary cigarette was lit and therefore the first car hit the road.

Our ancestors were bedeviled by airborne toxins whilst bipedal apes walking the African savanna, argued Benjamin Trumble, a biologist at Arizona State University, and Caleb Finch of the University of Southern California, within the December issue of the Quarterly Review of Biology.

But our evolutionary legacy can also be a burden, Dr. Trumble and Dr. Finch speculated. Some genetic adaptations may have increased our vulnerability to diseases linked to pollution.

It is “a really creative, interesting contribution to evolutionary medicine,” said Molly Fox, an anthropologist at the University of California, l. a. , who wasn't involved in the new study.

The story begins about seven million years ago. Africa at the time was gradually growing arider. The Sahara emerged in northern Africa, while grasslands opened in eastern and southern Africa.

The ancestors of chimpanzees and gorillas remained within the retreating forests, but our ancient relatives adapted to the new environments. They evolved into a tall, slender frame compatible with walking and running long distances.

Dr. Finch and Dr. Trumble believe that early humans faced another challenge that has gone largely overlooked: the air.

Periodically, the savanna would have experienced heavy dust storms from the Sahara, and our distant ancestors may have risked harm to their lungs from inhaling the silica-rich particles.

“When the dust is up, we’re getting to see more pulmonary problems,” Dr. Finch said. Even today, Greek researchers have found that when Sahara winds reach their country, patients surge into hospitals with respiratory complaints.