Lifespan has doubled in the United States in the past 150 years. This ridiculously wonderful change in the nature of life and death is something we tend to take for granted. When we do think about why we're still alive, some of the big, fairly obvious reasons that come to mind are vaccines, antibiotics, clean water or drugs for heart disease and cancer. But the world is full of underappreciated people, innovations and ideas that also save lives. A round of applause, please, for some of the oddball reasons, in no particular order, why people are living longer.
Cotton. One of the major killers of human history was typhus, a bacterial disease spread by lice. It defeated Napoleon's army; if Tchaikovsky's 1812 Overture were historically accurate, it would feature less cannon fire and more munching arthropods. Wool was the clothing material of choice before cotton displaced it. Cotton is easier to clean than wool and less hospitable to body lice.
Satellites. In 1900, a hurricane devastated Galveston, Texas. It killed 8,000 people, making it the deadliest hurricane in U.S. history. In 2008, Hurricane Ike hit Galveston. Its winds were less powerful at landfall than those of the 1900 storm, but its storm surge was higher, and that's usually what kills people. This time we saw it coming, thanks to a network of satellites and decades of ever-improving forecasting. More than 100 people died, but more than 1 million evacuated low-lying coastal areas and survived.
Fluoride. There were plenty of miserable ways to die before the mid 20th century, but dying of a tooth abscess had to be among the worst — a slow, painful infection that limits your ability to eat, causes your head to throb, and eventually colonizes the body and kills you of sepsis. Now it's a rare way to go, thanks to modern dental care, toothbrushes and fluoridated water.
Window screens. Houseflies used to be major vectors of deadly diarrheal disease. Clean water and treatment of sewage eliminated the most obvious means of transmitting these diseases, but pesky houseflies continued to spread deadly microbes. By the 1920s, according to James Riley in Rising Life Expectancy: A Global History, a growing aversion to insects and the introduction of window screens reduced this risk.
Botts' Dots. Those raised ceramic reflectors between road lanes were invented by Elbert Botts, a chemist who worked for the California Department of Transportation. The dots help motorists see the edge of their lane even in the dark or when it's raining. Botts died in 1962, four years before the first Botts' dots were installed on California highways.
The residents of Framingham, Mass. In 1948, researchers signed up 5,000 adults for a long-term study of heart disease. Nobody anticipated just how long-term the study would be — it's still going strong and now includes the children and grandchildren of the original cohort. It taught us much of what we know about heart disease. Before the study, for instance, high blood pressure was thought to be a sign of good health; now it's recognized as a risk factor for heart attacks and strokes.
Pasteurization. The rise of the raw milk movement suggests that a lot of people take safe dairy products for granted. Contaminated milk was one of the major killers of children, transmitting typhoid fever, scarlet fever, diphtheria, tuberculosis, and other diseases. One of the most successful public health campaigns of the late 19th and early 20th centuries was for pure and pasteurized milk — so successful that we don't really remember how deadly milk can be.
Shoes. Hookworms are parasites that enter the human body through bare feet — often by biting into the soft skin between the toes. The disease was common in the Southeast, spread when people walked barefoot across ground that was contaminated with feces of people who were already infected. Education initiatives at the beginning of the 20th century encouraged people to build sanitary outhouses and wear shoes.
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