Students are interested in disease, especially the diseases with a high yuck factor! Waterborne diseases fill the bill. Plus, this subject encompasses lots of important topics: sanitation, hygiene, the digestive system, water treatment, microbiology, etc. You can even look at history and warfare from a perspective of disease. So here are some pictures and a mini-lecture to get started. (I also mentioned one or two diseases that are not waterborne, just because their mode of transmission is interesting!)
In ancient history, before settlements were established, the world’s human population lived in small tribal groups that were nomadic. They hunted and gathered in one area till game ran low, then they moved on. And as they moved they left their wastes behind. A good idea, since human wastes can harbor disease!
But about 10,000 years ago people started planting seeds and domesticating livestock. This was a huge change that we call the first agricultural revolution, and it allowed humans to settle in one place. In time farmers became successful enough that they had excess grain that could be stored, encouraging the presence of rodents, which in turn carried diseases such as smallpox that could then make the jump into humans.
Isolated settlements sprang up, and they were usually located on a river or stream so people had plenty of water for drinking and for irrigation. And rivers were also used as handy places to dispose of wastes.
Over time the settlements grew into teeming cities and wastes built up, harboring microbes that caused outbreaks of epidemics. Merchants went from marketplace to marketplace, bringing diseases with them.
As the human population grew, settlements sprang up in the empty spaces between cities. At the point in time when settlements began to be located about two weeks’ walk apart. Smallpox: incubation period of fourteen days⇒epidemics!
Next: a phenomenal change occurred in human history: the Industrial Revolution. Threshing machines and other inventions could do the farm work and the out-of-work farm workers moved into the cities, to become laborers in factories.
Working conditions there were often miserable: long hours (dawn to dark), dusty, dark factories that were unsafe and closed in, no vacation, no sick-leave. Child labor was common, even in mines.
Living conditions for the poor were crowded and unhealthy, with several families living in one room of a tenement building. The air of the cities was dark with smoke and soot and the streets were filled with trash and garbage. Slaughter houses with blood, dung and flies were built in the cities, sometimes located next to schools. Rivers carried chemicals and raw sewage floating on the surface. Drinking water was accessed in public wells and was also taken directly from the river, bottled and sold untreated.
As shown in this fantastical newspaper cartoon of the 1800’s, people were starting to be disgusted by the appearance of the water, though they didn’t connect disease to the organisms that they could see in it with their microscopes (then popular as curiosities).
Outdoor privies were used for human wastes which collected in storage holes called cesspools, which were sometimes lined with brick or stone, but were sometimes just bare dirt.
It is estimated that by the 1850’s the city of London had 20,000 outdoor privies. In the home, for convenience, people used chamber pots. In the mornings, housewives tidied up by emptying the contents out the windows of the upper stories. Look out below!
These were the conditions when a cholera epidemic swept through the city of London in 1854. Cholera was, and still is, a fearsome disease. A victim can be healthy in the morning and dead by noon! It is characterized by nausea and vomiting, cramps, and severe diarrhea. Cholera sometimes breaks out, even today, where people are crowded together in conditions such as are found in many refugee camps, after a war or severe flooding or other natural disasters. Medical workers in these places often put the patients on cots such as the ones pictured, with buckets under the holes to facilitate clean-up of the diarrhea. So much fluid is lost from the body that vital minerals, needed for the heart to function, are carried away with the fluid, and the victims die of heart failure. In recent years it has been discovered that clean water mixed with a little sugar and table salt, given by mouth or intravenously, can spell the difference between life and death!
This brings us to London and the cholera epidemic of 1854. In one area of the city hundreds of people were infected and as many as 50% of the patients died. Queen Victoria summoned Dr. John Snow, a famous person in epidemiology even now, and directed that he stop the epidemic. This was a tall order since the cause of cholera and the means of transmission weren’t known then. In fact there was little understanding of diseases and germs at that time.
See The Poop Chronicles, Part Two, for the rest of the story, and for a fascinating activity modeling London’s cholera epidemic and asking students to figure out how to stop its spread.
No infringement of copyright is intended with the use of these pictures. Owners of copyrights can request removal and we will comply promptly.