Smartphone system detects lead in water

 By Agata Boxe

In 2014, what became a notorious water crisis fell upon the community of Flint, Michigan, when the city switched its water source and residents were exposed to high levels of lead

The issue called the world’s attention to lead contamination and its severe damage to human health. Now researchers have developed a new smartphone-based system that can detect high levels of lead in tap water.

What are we driking?

Lead may leach into drinking water through the corrosion of service pipes that contain the metal, according to the United States Environmental Protection Agency (EPA). Exposure to high levels of lead is particularly dangerous for children, potentially leading to issues with learning and behavior, lower IQ and hyperactivity, delayed growth, anemia and hearing problems, according to the EPA. In adults, the metal may cause cardiovascular and kidney issues as well as reproductive problems. The EPA also warns that, in pregnant women, lead may negatively affect the growth of the fetus and cause premature birth.
The EPA mandates that lead levels in water must be below 15 parts per billion. But researchers say that consumer test kits currently on the market cannot detect lead at this level. Now, researchers have developed an effective and inexpensive lead detection system based on smartphone technology.

Two smartphones and…

To build and test the system, scientists first constructed a smartphone microscope, then combined it with a smartphone equipped with an 8-megapixel camera. They then added a wide range of lead levels—ranging from 1.37 parts per billion to 175 parts per billion—to water containers. Next they added particles that, upon reacting with the lead, could be detected using colorimetry—a technique that allows chemists to detect the concentration of colored compounds in a solution—along with the microscopy employed by the new system. They found that the system was able to detect lead levels at 5 parts per billion in tap water, according to the findings published in September in the journal Analytical Chemistry. And, in previously deionized water, the system was able to test for levels as low as 1.37 parts per billion.
The researchers said that their goal was to create a useful consumer product. “We wanted to be sure we could do something that would be useful from the standpoint of detecting lead at the EPA standard,” study co-author Wei-Chuan Shih, associate professor of electrical & computer engineering at the University of Houston, said in a statement.
The new work builds upon a previous study, published in the journal Biomedical Optics Express, in which the authors converted a smartphone into a sophisticated DYI microscope.

The self-contained smartphone microscope can operate in both fluorescence and dark-field imaging modes and is paired with an 8-megapixel camera smartphone (University of Houston)

READ MORE: Dirty water = clean energy by Robin Wylie

about the author
Agata Boxe