The city of Flint, Michigan, has been engulfed in a drinking water crisis in recent months. In April 2014 the city temporarily switched its source from Lake Huron to the Flint River, and it was later discovered that the distributed water contained very high levels of lead. This month, Michigan’s governor declared a state of emergency and activated the National Guard to help distribute water filters, test kits, and bottled water to residents. And President Barack Obama has signed an emergency declaration that could provide Flint with up to $5 million in federal funds.
What’s behind the crisis? In part it’s water chemistry—the chemical reaction of the water and the pipes it’s flowing through—according to Philip Larese-Casanova, assistant professor in the Department of Civil and Environmental Engineering.
Larese-Casanova is an environmental chemist who studies the chemical processes of water pollutants, particularly metals. In a phone interview last week, he explained that the water supply in Flint was not treated with an anti-corrosive agent, which can bind to the surface of the metal pipes and form a protective layer that prevents corrosion.
The water from the Flint River was found to be highly corrosive, and causing lead and iron from the pipes to leach into the water supply.
“The water chemistry allowed the iron and lead to dissolve freely from the pipes,” he explained. “In my research I look at how different water qualities can corrode or otherwise react to pollutants that we release—either accidentally or through industrial waste processes.”
The water chemistry allowed the iron and lead to dissolve freely from the pipes
— Assistant professor Philip Larese-Casanova
He added: “We need to replace a lot of the pipes in (nation’s) infrastructure. They’re just too old. We need to replace them with safer materials. In order for that to happen, cities need a lot of money and they need a lot of time to dig them up and put new pipes in. That will solve a lot of problems.”
Health and environmental experts point to the dangers of lead to plants, animals, and humans. The EPA says lead is particularly dangerous to children because their growing bodies absorb more lead than adults do and their brains are more sensitive to lead’s damaging effects. The Centers for Disease Control and Prevention, meanwhile, says that no safe blood lead level has been identified.
At Northeastern, Larese-Casanova and his research team examine how pollutants can react in certain water conditions, and they run experiments to uncover the mechanisms and factors behind these reactions. One project is focused on metallic nanoparticles, which he says are increasingly being used in a range of commercial products, from TVs to creams and shampoos. Like the lead ions leaching from lead pipes in Flint, metallic nanoparticles can leach their toxic metals under certain water conditions. He is currently examining how cadmium and zinc ions leach from the smallest of nanoparticles, called quantum dots, which are now used in light emitting diodes such as those in TV displays. Another project involves investigating how naturally occurring metals, like selenium, behave in ground water and surface water. He is studying how selenium can bind with mineral surfaces and essentially remove itself from the water supply.
“If we can understand how metals behave when they enter ground water, we can assess whether they are a danger or threat to drinking water sources,” he said.
What can average residents do to ensure their drinking water is safe?
Larese-Casanova advises that people be alert to changes in the color, taste, and odor of their drinking water. He also suggests reading the drinking water reports that their municipalities release. If residents wish to be more proactive—and have the means to do so—he says they could even periodically send out drinking water samples to get lab workups that identify levels of metals and other contaminants.
Photo credit: Ben Gordon/Flickr-Creative Commons, license, photo cropped to fit image size