Though lead levels across America are far safer than even a generation ago, the lack of a solid answer on what the safe level is leads to concern that leaching, such as from water pipes, could be harmful.
As the crisis in Flint, Michigan a few years ago showed, the public can be put in a panic easily, and politicians will use public health concern for advantage, even after their decisions to stop using the science that had protected the public caused the problem.
At the American Chemical Society spring meeting in Orlando, scientists described a cost-effective and quick method that could make all lead pipes safe for carrying drinking water.
Historically, municipalities installed iron water mains that were connected to individual buildings by lead water pipes. Lead is natural, it is stable and it is malleable. Over time, chemicals in the water can cause the inside wall of the pipe to corrode, releasing lead ions into the water. With enough lead, poisoning can occur. Modern pipes now have a lining to prevent that but the cost to replace all water infrastructure is enormous and the problem had long been solved by corrosion inhibitors, phosphates which react with the lead ions to create compounds that deposit on the inside of the pipe. This coating, or "scale," blocks other lead ions from leaching from the pipe.
In Flint, the drinking water source was changed to a source that had different water quality while the city stopped using those scientific corrosion control measures. The protective scale dissolved, and lead ions leached into the water, setting off panic, creating a political firestorm, and causing a child to have debilitating lead poisoning. Lead poisoning in young children can cause a broad range of symptoms, including brain damage.
Since the safe level of lead is unknown, up to 18 million people across the U.S. could be at risk if the same thing that happened in Flint happened to them. That is why U.C. Berkeley grad student Gabriel Lobo and colleagues designed an electrochemical approach to the problem. They applied a small external voltage to a sample of pipe to speed up corrosion. As usual, the freed lead ions then reacted with phosphates in the water to form scale. The process took just a few hours, compared with a couple of years for the usual scaling method.
The researchers have tested their process in the laboratory but caution that they haven't yet conducted any trials on lead pipes in the ground. Currently, the group is working with experts from a local water utility in California to determine the practical parameters for a test under real-world conditions. They are also planning to conduct a test later this year at an Oakland school where normal scale buildup isn't happening in the pipes.
This would be welcome news to government budgets. While replacing pipes for each home and building would cost a small fortune, all to solve a problem that only happens when the science is ignored, this could be an ideal way to insure no kids are harmed in the future.