Why Do Millions Owe Their Lives to These Amazing People


There is a saying that for anybody who saves a single life, it is as if they have saved all of humanity. There are a small handful of people who have achieved even more than this, saving not one life but millions. Surprisingly few of them are household names. In this list we take a closer look at their lives and achievements.

10. John Leal

In 1908 a physician by the name of John Leal added chlorine to the New Jersey water supply. This was remarkable for two reasons. Firstly, chlorine is a poison, the same poison that would later be weaponized in World War One. Secondly, neither the government, local officials, nor the public who would be drinking the treated water had any idea what Leal had done.

In the early part of the twentieth century a glass of tap water might be swimming with potentially fatal bacteria such as typhus and cholera. Leal, who worked for a private company tasked with cleaning up New Jersey’s water supply, had become convinced that just the right amount of chlorine would kill off the bacteria without harming humans.

Worried that officials were likely to block any attempt to add poison to drinking water, he went ahead and did it anyway.

Leal’s actions created a scandal, and he was forced to explain himself in court. However, by that time the results were becoming incontrovertible. The mortality rate in New Jersey had fallen dramatically almost overnight.

Although he was accused of risking lives in order to make money for himself, Leal made no attempts to patent his chlorine filtration system and freely allowed it to be used by anybody who wanted it. The system he developed went on to save millions of lives around the world.

9. Alan Turing

At the outbreak of World War Two the Enigma machine was the most sophisticated cypher machine in the world. It could be configured in 150 trillion different combinations, leading the Germans to conclude it was simply unbreakable.

With the airwaves crackling with encrypted messages on everything from civilian railway timetables to the location of U-boats, there was a vast treasure trove of information just waiting to be unlocked. If only the British could find the key.

At Bletchley Park the British assembled a crack team, ranging from mathematicians to crossword experts, and set them the task of cracking the Enigma machine. The most brilliant of them all was an eccentric individual named Alan Turing. 

Turing and his team succeeded in cracking the Enigma code, but messages took weeks to decode, by which time they were often useless. Once again Turing was able to find a solution, designing a mechanical device known as the Bombe, each of which was capable of decoding hundreds of messages a day.  

It has been estimated that this huge advantage may have shortened the war by as much as two years, saving millions of lives in the process.

8. James Harrison

At the age of just 14 a young Australian named James Harrison underwent an operation to remove one of his lungs. Without blood transfusions he couldn’t have survived, so he pledged to become a donor and repay the debt.

While all blood types can save lives, Harrison discovered that his blood was very special and almost unique. It turned out his blood contained antibodies that could be used to treat Rhesus disease, which cause a pregnant woman’s blood cells to attack those of her unborn baby.

Harrison hated needles, but he would be enduring a lot of them. He donated blood almost every week for sixty years, although he says he never once watched the needle going in. He finally retired at the age of 81, having surpassed the maximum age a person is legally allowed to give blood in Australia.

He had by then earned himself the nickname “The Man with the Golden Arm” and saved perhaps as many as two million lives.

7. Henrietta Lacks

Henrietta Lacks was an African American woman who lived in Virginia at a time when racial segregation laws were still in place. Having received little or no formal education and working on a tobacco farm, there was little to suggest there was anything extraordinary about her.

While Henrietta’s life itself was relatively unremarkable, in death she would achieve a kind of immortality. When Henrietta died of cancer in 1951 a sample of her cancerous cells were sent on to doctor George Gey of John Hopkins Hospital for routine testing.

Gey was astonished to find they were like none he had ever seen before. Where the cells usually died quickly, under the right conditions Henrietta’s doubled every 24 hours.

These cells, dubbed HeLa cells, are effectively immortal and continue to be used in vital medical research to this day. They have enhanced our understanding of HIV, measles, mumps, zika virus, and were instrumental in finding a cure for polio. 

There is, however, a note of controversy. Henrietta helped to save millions of lives, but she had not given permission for her cells to be harvested.

6. Tu Youyou

Mosquitoes might be small, but they are one of the deadliest animals in the world. The diseases they carry kill millions of people every year. In 2018 alone there were more than 200 million cases of malaria worldwide.

Around 95% of these people did survive, and that’s in no small part thanks to a Chinese scientist named Tu Youyou.

Youyou began her work in 1960s Communist China, at a time when scientists and intellectuals were viewed with suspicion and mistrust. Her own husband, an engineer by trade, was detained by the authorities.

Youyou combined rigorous research methodology with a deep knowledge and respect of traditional medicines. This ultimately led her to conclude that a compound found in wormwood held the key to combating the malaria parasite. When animal trials proved effective, Youyou herself volunteered to become the first human test subject.

In 2015 she was awarded the Nobel Prize for her work in developing the malaria drugs that continue to save the lives of millions of people.

5. Ignaz Semmelweis


As far as his superiors were concerned, Dr. Ignaz Semmelweis was something of an eccentric oddball. His baffling insistence that the physicians on his ward washed their hands in chlorinated lime solution struck them as pointless, time-consuming, and very strange indeed.

In the mid-1800s this just wasn’t the done thing. It was common practice for doctors to move from treating one patient to the next, or even from conducting autopsies, without any effort to disinfect their hands. That this would be a very bad idea seems obvious today, but Semmelweis was one of the first people to work it out.

Semmelweis’s insistence upon cleanliness meant his maternity ward in Hungary had a mortality rate of just 1%; in nearby hospitals it could run as high as 20% or more.

While Semmelweis couldn’t offer a compelling scientific explanation as to why his methods worked, he knew they did and spoke of almost nothing else. Unfortunately, the establishment wasn’t ready to listen. Semmelweis was ignored, or even openly mocked, until in 1865 he suffered a nervous breakdown and was confined to a lunatic asylum.

He died just a few months later, possibly as a result of a beating he’d suffered whilst institutionalized. Semmelweis was ahead of his time, but he is now recognized as a pioneer of antiseptic policy and his methods went on to save millions of lives.

4. Norman Borlaug

At the turn of the century in the year 1900 the population of the world stood at a fairly manageable 1.6 billion people. By the 1960s that total had doubled to more than 3 billion. With the number of people increasing faster than crops could be grown to feed them, experts warned of an imminent catastrophe.

In 1968 the Stanford University professor Paul R Ehrlich predicted that hundreds of millions of people would starve to death over the next few years. There was, he said, nothing that could be done to prevent this.

This apocalyptic scenario was averted largely thanks to the efforts of just one man: Norman Borlaug..

Borlaug is known as the “Father of the Green Revolution,” and he devoted his life to boosting agricultural production in some of the poorest regions of the globe.

By adopting Borlaug’s methods and replacing previous crops with the high yield, disease resistant new strains he developed, countries such as Mexico, India, and Pakistan more than tripled their output in just a few years.

It has been estimated that Borlaug is responsible for saving more than a billion lives. He accepted criticism that his methods resulted in a loss of food diversity across the globe, but he pointed out the alternative was to allow millions of people to starve to death.

3. Ernst B. Chain & Howard Walter Florey

Alexander Fleming is famous for discovering penicillin, the drug which is often credited with changing the course of modern medicine.

This is undoubtedly a stunning accomplishment, but it’s fair to say it was achieved largely through luck rather than judgement.

While conducting an experiment in 1928 he noticed that a certain type of mold, which he later named Penicillin, proved to be extremely efficient at killing bacteria.  

The discovery had been made by accident, and while Fleming did investigate the possibility of using penicillin to treat infection in humans, he eventually gave up on the idea as unworkable. 

A German born scientist named Ernst B. Chain, working alongside Howard Walter Florey, picked up where Fleming left off. They achieved only a tiny fraction of the fame attached to Fleming, but it was this pair who first succeeded in synthesizing penicillin for human use.

Few people now remember their names, but Chain and Florey ultimately developed the drug that has already saved the lives of more than 200 million people.

2. Chernobyl Suicide Squad

On April 26, 1986 a routine safety check at the Chernobyl Nuclear Power Plant in the Ukraine went catastrophically wrong. One of the plants four nuclear reactors exploded, spewing out huge quantities of radioactive material into the surrounding area.

Chernobyl was history’s worst nuclear disaster, but it came close to being several orders of magnitude worse. As Soviet engineers and firefighters struggled to contain the disaster, a molten stream of radioactive material was burning its way towards a huge pool of water used as a cooling system. If they connected, it would result in a catastrophic explosion.

The valves that would drain the water away were located in a dark, flooded basement, and only a handful of engineers knew where to find them. The three men who volunteered to brave the radiation and descend into the floodwater became known to history as the Suicide Squad.

In successfully locating the valves and draining the water the men narrowly prevented an explosion that would have redrawn the map of Europe, rendering much of the continent uninhabitable for half-a-million years. Millions of lives were saved, and the Suicide Squad themselves even lived to tell the tale.

1. Vasili Arkhipov


In 1962 the world held its breath, as the Cuban Missile Crisis brought the United States of America and the Soviet Union to the brink of all-out nuclear war.

If the missiles had launched it would have been the end of civilization itself, and we came even closer to catastrophe than most people realize. Only the judgement of one lowly Soviet submarine commander prevented the Cold War from morphing into World War Three.

The commanders of Soviet nuclear-armed submarines enjoyed a huge amount of autonomy. If a commander believed the Soviet command and control network had been destroyed, he was entirely within his remit to launch a nuclear attack without waiting for orders from Moscow.

At the height of the Cuban Missile Crisis, on October 27, 1962, a heated discussion on this very subject took place beneath the waves of the Caribbean Sea. 

Having come under attack from American warships, the Soviet B-59 submarine had been submerged and cut-off from the outside world for four long, claustrophobic days.  Convinced that nuclear war had broken out above them, two senior officers gave the order to prepare to launch the B-59’s own missiles.

Fortunately, they could not do so without Vasili Arkhipov’s agreement, and the Soviet commander kept his cool. He insisted it would be prudent to make certain whether war had broken out before he started launching nuclear missiles. His decision that day may well have saved the lives of billions of people.

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  1. David Reisch on

    How about Dr. Frederick G. Banting, and the chemistry skills Charles Best, the discoverers of insulin. Without these men almost 100 years ago, there would be hundreds of millions if not billions of men, women, and children who would not be alive today

  2. Amazing! This might be the best top ten list in the history of top ten lists.