How to Engineer a Reliable $1 Sensor for Safe Drinking Water

Hundreds of thousands of people die from drinking unsafe water every year, according to the World Health Organization. For example, diarrhea transmitted from bacterial contamination is estimated to cause over 500,000 deaths annually. Toxic heavy metals in drinking water, such as arsenic, lead, and mercury, also pose huge health risks. And climate change will only exacerbate the risks of water-related diseases, according to the WHO.