November 19 marks the 7th World Toilet Day, which is designed to tackle the global sanitation crisis we face today.

A report released by UNICEF and WHO in 2019 shows that 4.2 billion people, more than half the global population, live without safely managed sanitation, among whom 673 million people still practice open defecation worldwide.

Toilets not only provide a good sanitation environment, but also affect people's health, and even life and death. Due to inadequate sanitation, at least 2 billion people use a drinking water source contaminated with feces globally, with 432,000 diarrheal deaths every year, according to WHO's statics in 2019.

Toilets have played an important role in people's lives throughout human history. After thousands of years of evolution, toilets recorded the footprint of human beings from barbarism to civilization.

The first toilets in the history of different civilizations

Archaeological findings show that the earliest toilet in China appeared more than 5,000 years ago at Banpo Village site of clan tribes, in Xi'an, northwest China's Shaanxi Province. The toilet was just a pit built outside the house.

The earliest Chinese records about toilets appeared in the "Book of Etiquette and Ceremonial" in the Western Zhou Dynasty (C. 1100 – 771 B.C.) According to it, ancient people dug a hole to use as a toilet. After the pit was full, slaves were ordered to fill the pit with soil and dig a new hole.

Toilets were also found in the Mesopotamian tracing back to 3,000 B.C. The facility composes a hole in the ground and a removable can placed underground. Although simple, it puts feces under people's control and prevents them from polluting the environment, making a significant step towards civilization.

A combination of toilet and pigpen

Chinese civilization is based on the agricultural revolution, and Chinese ancestors have learned the best fertilizer is to mix human and pig feces and ferment them in the soil for some time. The finding inspires the invention of the toilet with a pigpen during the Qin (221 - 206 B.C.) and Han (206 B.C. – 220 A.D.) Dynasties.

The toilet is elevated with a ladder for people to climb up and down, and the droppings fall into the pigpen below for pigs to eat. The archaeological proof was at a Western Han period Sandaohao site in Liaoyang, northeast China's Liaoning Province, where manure remains were found at a pigpen adjacent to the toilet.

Human feces can feed pigs, then pig manure and soil in the pigpen are used to fertilize the fields, and eventually pork feed people and increase people's income. In this organic cycle, the toilet becomes the portal connecting waste, pig raising and manure production, which is an effective and environmental-friendly way of development.

Flush toilet

In the tomb of King Liang Xiao at Mangdang Mountain, in Shangqiu, central China's Henan Province, the toilet has a stone pedestal pan, and a wall behind it curved a pipeline designed for water to flow through the toilet. The facility built about 2,000 years ago is considered the earliest flush toilet in China.

In the West, one of the earliest known flush toilets was built by Minoans living in the island of Crete in the Mediterranean region around 2,000 B.C. Wooden pedestal pans were settled on the drainage canal at the Palace of Knossos, with water flowing through the canal to flush the waste. Royals only enjoyed the luxury facility.

Since then, the craft of the flush toilet was advanced. The ancient Greeks and ancient Romans once used the public flush toilet, a big room in which long seats were settled to connect the drainage canal. But these toilet systems, which symbolize a high civilization, fell into disuse eventually.

It wasn't until 1596 that British Sir John Harrington invented a forerunner to the modern flush toilet with a flush valve to release water from the tank and down to empty the bowl.

The S-trap flush toilet was invented by Alexander Cumming in 1775 and is still used today. It has greatly facilitated people's lives and helped to create a good sanitary environment after the development of the sewage system in cities.

Cover image desinger: Liu Shaozhen