In fact, the majority of some 90 million people who live in the Punjab areas of Pakistan and India drink and cook with untreated well water that they collect themselves from privately-owed wells on their properties.
The main contaminant of the well water in this region of South Asia is arsenic—high levels of which can cause a range of illnesses, including cardio-vascular disease for adults and impaired cognitive function in children.
In the study—which was published online in Science of the Total Environment in November—Columbia University earth scientists partnered with Southeast Asian research professors and students to test more than 30,000 water wells in nearly 400 Pakistani and Indian villages.
They found that nearly a quarter of all the tested wells contain more than 10 micrograms per liter of arsenic, the World Health Organization’s (WHO’s) threshold in safe drinking water.
Fortunately though, the study found that 87 percent of households with a high-arsenic well live within 100 meters (or about 330 feet) of a private well that meets the WHO guideline for arsenic.
“If it’s 500 meters away instead of 50 meters,” he said, “that makes a big difference.” The students advised Punjab households with unsafe well water to switch to neighbors’ wells that are considered safe based on the test results.
“‘We hope you can [get along] with your neighbor so you can use their well.’” When the researchers returned to five of the Pakistani villages a year later, about two-thirds of the 150 surveyed households with high-arsenic wells claimed to have switched to a neighbor’s safe well.
In a previous test involving some 12,000 villagers’ wells across 60 Bangladesh villages, about 60 percent of households surveyed also made the switch to safe wells.
The testing campaign closest in magnitude to this kind occurred between 2000 and 2005, when Bangladesh’s national government tested nearly 5 million wells—an effort that convinced approximately 10 million local villagers to switch to safe wells.
And the only way to do that, is to actually test them all.”