Public health initiatives have been a major benefit of living in the 20th and 21st centuries. They've spared many of us from terrible communicable diseases, ensured we live past childhood, and helped cause human life expectancy to increase by 18 years worldwide in the past 50 years alone.
The idea of the public health initiative wasn't invented in the 1900s, however – let's take a look back at some of the earliest attempts to better the quality of life for society, with some dating back as far as 3,500 years.
Top image: Baghdad physician Al-Rhazi making one of the first smallpox diagnoses, via Adam Blatner.
Citizens in India and China Implement Variolation against Smallpox, 1500-1000 BCE
While the exact area and time of this practice has yet to be pinned down, individuals in China and India were using the scabs and crusts from the wounds of individuals afflicted with smallpox to inoculate others. This process, called variolation, was a method of deliberate infection that gave the infected degree of immunity. The scabs would be allowed to dry in bottles for several days, ground up, and then inhaled by the patient.
Those administering the inoculations also noticed a drop-off in the effectiveness of this technique, observing that the scab particles would be of less use the older they became. A very similar process is outlined as an Indian religious practice of the Vedic tradition dating to 1500 BCE. In addition to inhaling dried scar particles, placing a small portion of a smallpox wound into a freshly opened cut was also practiced in China.
The City of Rome and Waste Removal, 600 BCE
The Roman system of aqueducts and plumbing, at its height, including nearly of 1000 kilometers of piping and carried both fresh and foul water throughout the city and sometimes directly to residences by the first century CE. This system took centuries to construct, with the first major step coming with the construction of the Cloaca Maxima, which translates into the "Greatest Sewer", and served to remove water and waste from the city. If only mutagen existed then, maybe we would worship large, ninjitsu-knowing turtles. The Cloaca Maxima was finished in the sixth century BCE under the watch of King Tarquinius Priscus, using forced labor from Roman citizens.
With the advent of a sewer system, the luxury of public latrines could be conceived, with the first ones consisting of wooden planks with holes cut in them that sat above sewer lines. These were often used by soldiers stationed along Hadrian's Wall. After defecating, occupants would use a communal sea sponge to clean up in lieu of the yet-to-be-invented toilet paper.
The sea sponge was placed in bucket of salt water for the next benefactor. The holes in wooden planks would later become hewn stone openings in free-standing public latrines, some of which were available at no cost, while other were pay for play. Some denizens of Rome actually had latrines in their homes by the 1st Century CE. You'd get to have your own sponge then. I hope.
Keeping Sick People Away from the Rest of the Population, late 1300s CE
Surely this idea was in practice prior to the 1300s. However, the Black Plague was where this really became widespread as a public health initiative. The removal of bodies infected with the plague, however, this did not stop the fleas that caused the Black Death.
Individual cities would contract with "Plague Doctors" – denizens who would visit the sick and keep a tally of the numbers of those afflicted, and, in some cases, help remove bodies. The Plague Doctors were extremely visible (and ominous) due to their outlandish clothing and beaked mask, designed both to protect the individual and provide a hospitable work environment (the horned beak stored spices to help the plague doctor mask the stench of the bodies he would come in contact with).
These measures, while not extremely useful in controlling the spread of the Black Death (they, in fact, possibly led to the spread of Black Death as a Plague Doctor went from city to city carrying fleas), laid the foundation for later organized efforts to fight community-wide diseases.
Non-Municipal Initiatives & our Body's own Defense
Some initiatives date back upwards of hundreds of thousands of years, including burial rituals and warnings against eating certain types of food. But these came in the form of religious instructions, and not government-initiated decrees. It is also important to not that our bodies themselves have inherent protection against harmful material, as a correlation between foul odors and infectious material is often observed (i.e., feces, rotting flesh).