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Road Salt May Be Linked to Lead Poisoning in U.S. Cities

Researchers say the crisis in Flint could repeat itself across the country.

| 3 min read

Researchers say the crisis in Flint could repeat itself across the country.

Salting the roads is a very common practice during the cold winter months — it de-ices the streets and highways, and prevents many accidents.  However, this salt may be poisoning the drinking water in many U.S. communities, scientists say.

For example, in Flint, Michigan, thousands of families have suffered health effects ranging from skin rashes to possible brain damage in children due to high amounts of lead in their drinking water.

Unfortunately, some U.S. cities still have 100 percent lead piping bringing water from the utility stations to homes and businesses, and nearly all homes built prior to the 1980s have lead solder connecting copper pipes.

The use of lead goes back thousands of years to the first plumbing systems.  It was used because of its ability to resist pinhole leaks, while also being soft enough to form shapes that deliver water efficiently.  Lead was actually used for many common products until its toxicity was discovered.

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Lead pipes are still in use today because those running the water utility can create a chemical barrier between water and the pipe to prevent lead from leaching.  It is a chemical process that is carefully controlled.  However, something went very wrong in Flint.

Many residents are furious, and rightfully so, with the people who ran the city’s water supply and failed to treat the water properly.  They are also angry with state and federal regulators who residents say did not fix or address the problem for nearly two years.  

Researchers believe that high levels of chloride from road salt corroded the pipes, dislodging lead particles into the water.  “We are essentially salting our earth,” said Marc Edwards, professor of water engineering at Virginia Tech.

“We are putting 130 pounds per person on the roads each year in the U.S. and it’s already doubled the level of salt in many U.S. rivers,” he told Discovery News.  “The potential consequences of this are quite extraordinary.”

In 2015, the National Science Foundation (NSF) gave Edward a $50,000 grant to investigate Flint’s water distribution system.  What he found was that chloride concentrations in the city’s drinking water had soared from 11.4 milligrams per liter (mg/L) to 92 mg/L after officials switched from the Detroit River to the Flint River.

“Salt can serve as a trigger for lead leaching,” Edwards said. “We are researching this now.  This really escaped my radar until these events.”

Alarmingly, it is not just Flint experiencing this problem.  Residents in Brick, New Jersey have been warned about high lead levels in their drinking water for the past two years.  Officials believe the problem started when saltwater from Hurricane Sandy started to corrode lead soldering in pipes from homes built before 1987, explained Edwards.

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And now, residents in Sebring, Ohio have been warned to not drink their tap water.  Elevated lead levels were detected last year, but officials did not warm residents for months.

To combat this ever-growing problem, some cities and towns are reducing the amount of salt used on the roads because of the issues related to health and the environment.  Unfortunately, salt is still the most popular way to clear snow and ice from asphalt, however some alternatives have been developed.  

For example, mixing a brine of water and salt with carbohydrates like beet, wine, beer or cheese extracts allows the mixture to stick to the road surface, and it even lasts longer than traditional road salt.

Reducing the use of road salt is not always easy, especially for local governments that do not have the money for it.  However, it is possible.  I am sure all of us believe the benefits of switching de-icing techniques and keeping people healthy far outweighs the costs of making these changes.

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