Background

In many countries, water is a necessity. It's used for drinking, showering, cooking, washing dishes, and doing laundry. Yet as the recent crisis in Flint, Michigan shows, its purity and safety is not guaranteed. In Flint, city officials trying to save money on water temporarily supplied the city with water from the Flint River. The water contained bacteria, so residents were advised to boil the water. However, the chlorine used to treat the bacteria reacted with other compounds in the water to produce total trihalomethanes (TTHM), which could be carcinogenic. And, as news headlines declared, the water contained dangerously high levels of lead because the water corroded the pipelines and allowed lead to seep in. City officials did not proactively treat the water to prevent corrosion. And although residents complained about the water quality, city officials maintained for several months that the water was safe to drink (NPR).

Lead's toxicity is a result of its similarity to minerals our bodies need such as zinc, iron, and calcium. It can enter the body through inhalation, ingestion, or absorption through the skin. Through the pathways of these minerals, lead is distributed throughout the body. Lead is especially dangerous for young children and fetuses, in whom it interferes with development, resulting in symptoms ranging from speech and language problems to decreased bone and muscle growth. Other common sources of lead poisoning in children are lead-based paint, used in old houses, and contaminated soil (KidsHealth). In adults, lead poisoning can lead to high blood pressure and kidney problems (EPA). In children and adults, even a trace amount of lead can cause problems, but the maximum contaminant level (MCL) in drinking water set by the EPA is 15 parts per billion (ppb). In 2015, a year after Flint changed its water source to the Flint River, the a resident's water was found to contain over 13,000 ppb of lead. In the same time period, an increased percentage of children in Flint had elevated blood lead levels (NPR).

The Flint water crisis has sparked national concern about lead contamination in water. Cities are scrambling to test their water lest they become the "next Flint." In the past few months, the city of Pittsburgh has found lead levels that are dangerously close to the EPA's MCL or higher. This awareness is beneficial for the residents, but the power still lies within city officials. Residents need a device to test for lead in their own homes. Current lead sensors for home use exist, but they cost about twenty to thirty US dollars (USD)--inaccessible for over 40 percent of Flint's population and over 14 percent of the US population, which lives under the poverty line (NPR; US Census Bureau). Thus, we are developing Hot Metal Switch, a sensor that could cost mere cents, for residents to test their own water whenever they wish.

References

National Public Radio (NPR). Lead-Laced Water In Flint: A Step-By-Step Look At The Makings Of A Crisis. 2016, April 20.
KidsHealth from Neymour. Lead Poisoning. 2016.
Environmental Protection Agency (EPA). Table of Regulated Drinking Water Contaminants. 2016, July 15.
United States Census Bureau. Income and Poverty in the United States: 2014. 2015, September.
Royal Society of Chemistry (RSC). Chemistry in Its Element - Thallium.
Agency for Toxic Substances & Disease Registry (ATSDR). Toxicological Profile for Thallium. 2015, January 21.
National Environmental Methods Index (NEMI).
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