Links to all references can be found at the end of the lesson
Table of Contents
Roughly 60% of your body is made of water. In vital organs like the brain and lungs the number rises to around 80%. Therefore, given that many of us drink, cook with, shower with, and clean with tap water every day, it is one of the most important variables to consider.
Now, water quality depends on several factors:
Because of this, water quality varies wildly across and within countries.
Since 2019, more than 320 so-called "forever chemicals" or "persistent organic pollutants" (POPs) have been found in U.S. drinking water, with dozens more being discovered every year [1.1], including…
Arsenic is a heavy metal known to cause skin, lung, bladder, kidney, and liver cancer, as well as nerve paralysis and blindness. [4.1]
In the mid-1800s through the mid-1900s, inorganic arsenic compounds were often used as pesticides. They also had a medical role that extended until the 1970s, primarily for treating conditions such as leukemia.
In the 1970s, there was a transition in arsenic usage, with a shift away from pesticides toward their use as wood preservatives. So, by the year 1980, wood preservation had become their primary use.
Because arsenic was indeed so popular until recently, and because it is naturally found in the Earth’s crust, it can sometimes make its way into our water supply. Out of all the things we will list, arsenic—or, more generally, heavy metals as a whole—tend to be particularly noxious, especially when found in their inorganic form.