Lengthening Lives: 7 ways Science Has Changed Lifespans

PORTSMOUTH WATER 1927 Slow Sand Filter in Operation

Clean Water

Access to clean drinking water and appropriate waste water management has also had a substantial impact on human life spans. Without clean water, whether in the past or in parts of the world today, people are at risk for a wide-range of water-borne parasites and illnesses. Today, 1.8 billion people rely on contaminated drinking water sources, so unfortunately, this issue isn’t just history.


Many different illnesses can be spread through contaminated water sources—and let’s be clear here; when we say contaminated, we’re referring to fecal contamination or poop—including cholera, dysentery, dengue fever and campylobacters. In order to understand how this impacted the past, you need to think about where people got water from, and how they handled both human and animal waste of various sorts.

In some historical periods and places, like ancient Rome, people had access to relatively clean water sources. Fountains provided drinking water delivered from the countryside in Rome. That was, however, an exception to the general water options available historically. In most cases, people got water from local streams, rivers, and ponds. These ranged from relatively clean, in the case of a rural spring to downright disgusting, in the case of the Thames River.

Providing clean water is a two-part process. People need access to sources of clean water, like wells, springs or fountains, but also need a way to appropriately manage waste. That means latrines situated well away from flowing water, indoor plumbing, and measures to ensure that other forms of waste, like the leftovers from a slaughterhouse, are not dumped into the water.

While efforts to provide clean water date to the ancient world, the first municipal water purification plant didn’t open until 1804. Municipal water filtration was introduced in London in the 1850s. These measures were especially important as pollution grew with the industrial revolution, putting traditionally clean water sources at risk. Today, wells and water purification systems are still needed to provide clean, safe water in many parts of the world.