Scientists Now Know Exactly How Lead Got Into Flint's Water

New report blames corrosion and warns that fixing lead poisoning nationwide will require more work than we hoped.

For decades, the pipes that brought water to LeAnne Walters’ house did their job unnoticed and safely. But in summer 2014, that changed. Suddenly, Walters found that the water spewing out of her faucets was discolored and foul-tasting; her son would come out of the bath with alarming rashes.

After meticulously sampling her house’s water and testing it with at-home testing kits, Walters discovered that it had lead levels far higher than those considered safe. The chemistry of the water flowing through her pipes had changed profoundly—with toxic results.

Walters tried to contact city and state officials for guidance, but was mostly ignored. That’s when she reached out to Marc Edwards, an engineer at Virginia Tech University who studies water treatment and aquatic chemistry.

With Walters' assistance, Edwards and his team conducted the first major study showing that lead levels in the water of more than a hundred of the city's homes exceeded safe levels in 2014. For a new report, published yesterday in the journal  Environmental Science and Technology , Edwards' team returned to “ground zero” and used chemical analysis of water samples to see just how deep the contamination in Walters’ home ran.

The team concludes that that avoiding lead contamination may require far more work than some think—and may even necessitate a nationwide overhaul of America’s outdated plumbing.

An in-depth chemical analysis of water from the "ground zero" house in Flint's water crisis finds that corrosion is to blame.

The root cause of the Flint lead crisis was corrosion, the new study confirms. For 50 years, Flint had purchased its water from Detroit, its neighbor 70 miles to south. However, in 2014, the cash-strapped city decided to end its agreement with Detroit and start pulling water from the Flint River until a new aqueduct was built. What officials didn't seem to anticipate was the effect that the slightly more acidic water of the Flint River would have on the city's pipes.

Furthermore, officials never used common corrosion control methods that Detroit and many other cities use in their water systems. Those methods include adding phosphates to the water, which help keep lead from dissolving into the water flowing through the pipes. When the city switched water supplies, this rust began to be stripped away, strongly discoloring the water and leaching the large amounts of lead from that rust into the water.

The corrosive water pumping underneath Flint quickly ate away at the protective layer inside the city's old lead pipes, exposing bare lead to the water flowing through them. This lead was the source of the initial contamination, Edwards says. This is what happened in Walters’ house: According to the study, most of the lead appeared to come not from the lead pipe connecting her house to the main line, but from the protective rust that had built up on the house's iron piping over the decades.

Flint switched back to using water from Detroit in October 2015, and is now adding extra phosphates to that water to help reduce lead levels. But these measures amount to just a "band-aid," according to Edwards.

By Ben Panko​​

Read more at: Smithsonian

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3 Comments

1. A big elephant in the room in Flint is even more dangerous than lead in the water. Degrading lead-based paint, paint dust, and roadway dust lead is more of a long term contaminant threat that has been ongoing for a century. This is true of most towns that have existed for more than fifty years. Lead paint chips are sweet tasting and the dust gets picked up on thumbs sucked by toddlers. The drinking water only adds to the exposures... tragically.

2. Test results can only be as good as the integrity and intention of who is doing the sampling and analysis. The avoidances described in this article are routinely employed all around the nation, giving very biased assessment of the risks and harms to real living, breathing, individuals that we know and love. The legislators are the regulators of the regulator agencies in each state, setting the funding prioritization and holding agencies that find additional water contaminant problems hostage. If agencies try to do due diligence for water quality assessment for lead, they often suffer punitively reduced funding for other good work that they find necessary while trying to inform public health protections. Therefore, biases and outright fraud play a major role in water quality sampling, site selection, analysis, and assessment for risks. As a result, our children and grandchildren are poisoned and become less capable of being all they could be. We can't even seem to change fishing regulations to use alternative fishing sinker materials that are less toxic. Our tackle boxes with sinkers in them get heavily contaminated by a fine black, nearly pure lead, powder that gets on hands, apples, sandwiches, cooler ice, and fish... that we take home to the frying pan. Congressmen, that pride themselves with teaching their grandchildren to fish, don't even know that they are poisoning the lunches of the children by using such highly contaminated tackle boxes. Pure lead particulate enters living breathing children we love... and they suffer the many toxic effects of lead.... repeatedly. Virginia Tech had to step in to do the work of the state water quality-responsible agencies because the agencies are not supported to do due diligence that we hire them for. The legislators across the land, both state and federal, are most often irresponsible because of the intense politic against toxic contaminant scientific assessment. Great societal harm is done, prisons increase in population, IQs drop,and we take two to four times the learning experiences to realize the consequences of our actions. States that have naturally corrosive waters are at increased risk needing careful pH corrective action, and prevention of toxic metal contact with drinking water.

3. The blood lead levels used to indicate harm potential status and trends in public health can be very misleading, since they primarily only indicate current lead exposures or uptake only during the last several months. Blood lead levels quickly reduce by the body sequestering the lead in bones and teeth in accumulative fashion. This sequestration does help the current toxic risk of other physiologic pathway degradation, but tends to only put off the risks until stresses later in life (old age, illness, or pregnancy) develop to cause the body to seek to mobilize the calcium stores in bone to fill the sudden need for added calcium to build defensive molecules needed to counter the stresses. At such times, calcium is low in supply, and since the body does not correctly identify lead as being other than calcium, lead comes out with the Ca and becomes incorporated into the defensive components being made from calcium and zinc. This contamination of stored lead makes many of the molecules such as zinc finger proteins dysfunctional. The body thinks that it has responded well to the stress but has not because the accumulated body lead has poisoned the bodies’ defenses. Blood lead levels can thus drop well, because either the exposures have lessened, or because the body has been effective in storing it in bone, or both mechanisms. Any time the blood lead drops it helps the current pathogenicity of the lead to the immediate physiology, but usually only postpones the damage till later in life when stresses remobilize it at precisely the vulnerable times of old age, illness, or pregnancy. Once body burden has increased, we all have increased risks through life from that lead uptake that has occurred earlier. The public health paradigm commonly misrepresents the meaning of the blood lead testing results, erroneously giving the impression that the dangers from the lead exposures have all passed, but science is not served well by this incomplete picture provided by the authorities. Bone lead levels are now 100 to 1000 times those that prehistoric bones had accumulated. Our bodies have not had evolutionary time elapsed to adapt better defense mechanisms to the greatly increased environmental pollution once we dug the lead up out of the ground and dispersed it around the globe as products that easily degrade to be taken up to contribute to our health challenges. As you say, prevention is primary, because once in the body, much of it stays there to eventually do more damage.