Mercury Poisoning

If you’re glued to your smartphone for its endless apps, consider a feature that could save the lives of millions: The ability to detect dangerous levels of mercury contamination in water. The technology is far from mainstream, but chemists at the University of Burgos in Spain are closer to making this innovation a reality with their invention of color-changing sheets that signal mercury levels in liquids.

The new research, published in Analytical Methods, could take the guess work out of water purification so that people can avoid contaminated water and ecosystems affected by mercury can be properly identified and cleaned.

How Does it Work?

Sheets of polymer membrane are given colorimetric properties, meaning that they change color when they come in contact with a certain substance. In this case, the sheets turn different shades of red in the presence of mercury levels that exceed limits set by the Environmental Protection Agency (EPA). (However, levels can be adjusted depending on the desired boundaries.)

This color change can be easily detected with the naked eye, but taking a photograph with a cell phone camera and putting it through image treatment software offers a more accurate measurement of the mercury content in a water sample.

What Does This Mean for Global Health?

As the adage goes, water, water everywhere, but not a drop to drink. Water supplies worldwide are being contaminated by high levels of mercury, making bodies of water unsafe for humans and wildlife alike.

Access to clean, potable water is a major public health issue, especially in developing countries that rely on direct water sources for survival. Contamination can come from a number of sources, including untreated sewage, factory discharge, and landfill runoff.

This becomes especially dangerous when fish are poisoned by mercury. When people consume fish that have come in contact with mercury, they risk developing a host of diseases and ailments, including mercury poisoning, birth defects, and even death.

More stringent environmental regulations must be put in place before we'll see a significant reduction in water pollution, but at least for the time being we can better detect the dangerous chemicals that put our lives and communities at risk.

"Anyone, even if they have no previous knowledge, can find out whether a water source is contaminated with mercury above determined limits," says researcher Felix C. Garcia. Should Garcia's color-changing sheets make their way into the mainstream, this simple technology will be available to anyone with a cell phone.

“Detecting and quantifying chemical species are some of the key challenges in chemical research, particularly in environmental control, where the detection of contaminants by easy, rapid, and inexpensive techniques has always been of the utmost importance,” the researchers said.

We'll drink to that.

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