A1965 photo of Chevrolet's rear-engine Corvair Corsa sports coupe. AP

Window screens, spittoons, and the Chevrolet Corvair are part of Johns Hopkins University’s list of objects that changed public health.

The quality of life in American cities has come a long way since the Johns Hopkins Bloomberg School of Public Health first opened its doors in 1916. Back then, sewage systems were rare, living conditions were deplorable, and polluted water regularly made it into the drinking supply. Communicable diseases spread rapidly among crowded populations, with outbreaks decimating entire cities.

“The great flu was right around the corner, and thousands of people died in cramped and horrible conditions,”says Joshua Sharfstein, an associate dean at the university. “That episode particularly revealed how vulnerable cities were to infectious diseases.” Called the Blue Death, the 1918 influenza pandemic spread across cities including Baltimore, Philadelphia, New York, and New Orleans, eventually killing an estimated 20 to 50 million people worldwide.

Fast-forward 100 years, and public health has come to the forefront of urban planning. Garbage trucks have rolled in to clean up cities, vaccines have nearly wiped out dangerous diseases such as measles and polio, and the use of water-treatment plants spread from Baltimore to cities across the world. And over time, new public-health concerns have arisen, from the polluting effects of the auto-industry boom to the use of lead pipes.

Some of these items have made it onto Johns Hopkins’s list of 100 objects that shaped public health, created to celebrate the public-health school’s centennial. Some have, for better or worse, an obvious connection to public health, including automobiles, toilets, and cigarettes. Others are a bit unexpected—such as spittoons, smartphones, and the Chevrolet Corvair.

“We wanted to be thought-provoking, to make people think about the connections,“ Sharfstein says. “Public health is defined by the end result, which is health, so a lot of things can sit as public health issues because they affect whether people live or die.”

A 1967 ad for General Motors touts the Chevy Corvair as one of the “best handling cars you can buy.” (SenseiAlan/Flickr)

The Chevrolet Corvair

To those who didn’t drive in the 1960s, the Corvair might look like any other classic compact car. But this particular model became the catalyst for road safety after then-unknown consumer advocate Ralph Nader published a book lambasting it for being Unsafe at Any Speed. Nader called out General Motors for the car’s suspension defects, which he claimed could not only make drivers lose control of the car, but also cause the cars to roll over. The company refuted those claims, but the damage was already done.

Following public outcry and diminishing demand for the car, GM finally halted the production of the Corvair in 1969. And Nader’s book helped pushed the passage of the National Traffic and Vehicle Safety Act, which turned 50 this month, and forced the federal government to enact safety standards for cars and roads. “Until that time, people thought, 'Well, cars were what the manufacturers made,' and that safety was something people just had to deal with,” says Sharfstein.

Today, road safety has become one of the leading public health concerns in the world. And despite the prominence of traffic lights, bike lanes, speed limits, and airbags—all included in the Johns Hopkins list of public health objects—the U.S. still trails behind several other high-income countries in road safety. In fact, the Centers for Disease Control and Prevention recently reported that the U.S. has one of the highest car-crash death rates, with more than 32,000 deaths each year.

Felipe Dana/AP

Window Screens

We don’t usually pay much attention to the mesh screen that covers our windows. But we really should be much more thankful for window screens—a Civil War-era invention that happened after an employee coated wire sieves with paint and sold them as an alternative to cheesecloth, which was used to keep bugs out of homes at the time. As the researchers at Johns Hopkins note, screens are our first line of defense against virus-carrying mosquitoes.

“People in Minneapolis may not be thinking of their window screens as public health objects, but they sure are in Miami,” Sharfstein says. “Suddenly in Miami, everybody is paying attention to their window screens with the Zika virus in mind.”

Spittoons on the floor of a barbershop in Martinsville, Virginia. (Wikimedia Commons)


Not all objects have positively shaped the public-health sphere. Back in the 19th and early 20th centuries, everyone spat. They spat in train stations, banks, saloons, and even congressional offices. Not on the floor, but in spittoons. These were essentially brass dishes or bowls used to contain saliva or chewed tobacco, and they were ubiquitous. (“Think ashtrays for saliva,” the Johns Hopkins staff writes.)

But this was also an era when the threat tuberculosis loomed over cities. Researchers were concerned that spitting would further spread TB by infecting workers who had to clean the spittoons. Cities across the globe launched anti-spitting campaigns, fining people for the act. Spittoons soon became a relic of the past, and spitting has become an urban nuisance that’s looked upon with disgust, and an issue of public hygiene in the eyes of many.

As CityLab’s John Metcalfe—a proponent of anti-spitting laws—reports, the act has remained illegal in cities throughout the U.S., such as in Daytona, Florida. Spitting also comes with a hefty fine in cities in Hong Kong and Singapore.

This smartphone app is used for eye examinations at a temporary clinic near Kenya's capital, Nairobi. (Noor Khamis/Reuters)


Smartphones have been a double-edged sword in the realm of public health. On the one hand, they have led to distracted driving, and therefore, more road deaths. They have also been vital to people in developing countries, where building a reliable telephone infrastructure is too costly, according to Sharfstein. “The smartphone is allowing these countries to take a leap over a huge technical obstacle, to get people connected,” he says.

Plus, smartphones have been a key tool for researchers, from those who rely on social apps and selfies to measure mental health to those who use mobile alerts to spread messages about family heath and vaccine delivery. And with satellite technology, which enables phones to be used without an intricate network, vital information can go from the field to the lab in a matter of seconds.

A man from the Cambodian Mine Action Centre feeds a rat undergoing training to detect mines. (Samrang Pring/Reuters)


Yes, rats terrorize subway commuters and disturb the occasional picnic in the park. But they are perhaps the unsung heros of public-health advancement. According to the Johns Hopkins list, rats and mice make up 95 percent of lab animals. Despite understandable ethical concerns, they’ve helped researchers understand everything from the value of vitamins to how diseases spread.

Rats are increasingly also being studied in their natural settings, as well. And in some countries, rats are even directly saving lives by sniffing out diseases such as tuberculosis. Those same rats, from the nonprofit Apopo, which trains rats for humanitarian purposes, have been hailed as heroes for finding landmines in places including Cambodia and Mozambique.

(Vivek Prakash/Reuters)

Air Conditioners

We’ve grown to love and hate them at the same time, but the truth is, some cities—with temperatures reaching well into the hundreds—could not exist without the advent of air conditioners. In the U.S., according to the folks at Johns Hopkins, air conditioning has reduced the chances of people dying on an extremely hot day (defined in the study as exceeding 80 degrees Fahrenheit) by 75 percent.

Heat exhaustion may not be an issue in offices where the A/C is often cranked too high. But for outdoor workers in cities close to the equator, global warming can prove dangerous. “There have been thousands of people who have died in heat waves,” says Sharfstein. The 2015 heat wave in parts of India alone, for example, brought temperatures as high as 117 degrees and left nearly 2,000 people dead.

At the same time, air conditioning is a contributor of greenhouse gases, one of the major causes of climate change. “That is one of the central questions in the next century,” Sharfstein says. “How can we accomplish critical goals for human health while preserving the environment?”

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