January 26, 2016 — Harvard Chan School’s Philippe Grandjean, an expert in how environmental pollution impairs brain development, says that Flint, Michigan’s water crisis could have been prevented, given the United States’ long experience with lead contamination—and how to prevent it.

Flint, Michigan temporarily switched its water supply from Lake Huron to the Flint River in April 2014 to cut costs. Should officials have known that lead contamination would result?

Yes. We are dealing an ancient problem. Lead, a malleable and inexpensive metal, has been used for water pipes since the Roman period. It’s been known since then that toxic amounts of lead from these pipes could be released into soft water. This can occur because lead can be dissolved by weak acids found in many water supplies.

The solution was well known, either the lead pipes had to be removed or water quality had to be changed. Replacing the pipes can be very costly, especially if their locations are no longer known, so adding lime and other corrosion inhibitors to community water has often been used as a remedy.

Even with these known problems, it was only a few decades ago that plumbing codes were changed to require water pipes be made of materials other than lead. So today, a substantial number of service lines, distribution lines, and household water pipes in American communities are made of lead.

Flint is by far not the first community where lead poisoning has emerged as a “new” problem. Fifteen years ago, Washington, D.C. changed the disinfection chemical for the municipal water supply from chlorine to chloramine, which caused lead to leach from the water pipes, and the problem was not corrected until three years later. More recently, similar problems have occurred both in North Carolina and in Maine. In all of these cases, the problems could have been foreseen, but decisions on water treatment were primarily made based on considerations of cost and feasibility. Last week it was reported that tap water in Sebring, Ohio had elevated levels of lead. It’s just another example that ancient water pipes made from lead will continue to cause problems.

Can you characterize the extent of the lead-poisoning problem in Flint?

Some water analyses conducted in Flint have revealed lead amounts huge enough to cause clinical poisoning, and severe elevations of lead concentrations in blood have been found in large numbers of residents. High lead levels can cause serious health issues, particularly in children.

Last October, the water supply was switched back to the Detroit system, with water from Lake Huron, and a corrosion inhibitor, orthophosphate, was added to the water. By now, it seems that the immediate problem has been resolved. However, as long as water pipes made of lead remain in place, the problem may re-emerge if the water again becomes more corrosive.

What are the long-term health ramifications of the crisis?

The problem in Flint is sad and also infuriating, because lead is perhaps the most extensively studied pollutant. Thousands of investigations have shown that lead is particularly toxic to the brain, especially in children. Much of that evidence was collated in connection with the immense pollution from lead additives in motor fuels. Increased exposure to this metal is known to cause an increased risk of mental retardation, ADHD [Attention Deficit Hyperactivity Disorder] and other serious ailments. In a more general sense, lead exposure causes mental deficits that result in poor school performance and decreased educational achievements. When calculated from the loss of lifetime income, the societal costs from increased lead exposure reach billion dollar amounts.

In Flint, the costs will not be apparent in the short term. But the brains of the Flint children have suffered from the lead exposure, and they will carry the burden the rest of their lives. We should not allow this to happen again.

— Karen Feldscher