(REBECCA COOK/REUTERS)

Yanna Lambrinidou is an adjunct assistant professor in the department of science and technology in society at Virginia Tech.

Marc Edwards is the Charles Lunsford professor of civil engineering at Virginia Tech.

For months, the citizens of Flint, Mich., were on their own in trying to bring attention to their city’s polluted water. In August, one of us, Marc, brought his research team to Flint at the request of Flint resident LeeAnne Walters, who couldn’t get the government’s help in dealing with the orange dreck coming from her tap. The team found that Flint’s water supply contained very high levels of lead, a toxin linked to health problems ranging from tooth decay to neurological disorders. It took decades, but Americans eventually got smart and banned lead paint. Yet when it comes to lead in water, even with the political and media spotlight on Flint, misconceptions persist.

1. Flint is an isolated case.

Flint has attracted national attention because the situation there seems so singularly outrageous. Editorial boards have called to mind the Hurricane Katrina disaster, accusing state and federal officials of turning a “blind eye” to a crisis “beyond measure.” Steve Via, regulatory affairs manager for the American Water Works Association, which represents utilities, insists, “In general, lead is pretty well managed across the country.”

That’s wrong. It’s not unusual for cities to have lead in their water supplies. In 2004, The Washington Post reported that 274 water utilities serving 11.5 million consumers had exceeded the Environmental Protection Agency’s lead standard in the previous four years and that several cities (including Boston, New York and Philadelphia) were out of compliance with EPA reporting requirements. As Erik Olson of the nonprofit Natural Resources Defense Council said at the time, “The problems we know about are just the tip of the iceberg.”

More than a decade ago, it was found that Washington, D.C.’s tap water exposed two-thirds of over 6,000 tested homes to lead doses that exceeded the EPA’s limit of 15 parts per billion. Exposure was associated with a 37 percent increase in fetal deaths and hundreds of cases of elevated blood lead levels in young children.

One problem is that health authorities don’t appreciate that the threat from lead-contaminated water can be just as dire as that from other sources. The CDC, for instance, declares lead-based paint to be “the most common high-dose source of lead exposure for children” and states that, “in general, lead in drinking water is not the predominant source for poisoned children.” Even in direct response to concerns about Flint’s crisis, state health officials in Pennsylvania said, in part, that “the primary source of childhood lead poisoning in Pennsylvania continues to be exposure to aging, deteriorating lead-based paint (chips and dust), and not drinking water.”

But lead in water is a significant cause of elevated blood lead levels in children. In Flint, those levels doubled. What’s more, the Flint water lead levels are similar to those encountered elsewhere.

2. If water meets EPA standards, it is safe.

The EPA’s Lead and Copper Rule, promulgated in 1991 under the Safe Drinking Water Act of 1974, calls for municipalities to issue detailed annual reports about water quality. Flint’s 2014 report says that 90 out of 100 samples of water collected in the second half of that year contained six parts per billion of lead or less — well within the permitted threshold of 15 parts per billion. Technically, this meant that Flint was in compliance with national standards.

This is misleading. Flint was using water from the Flint River, which corroded city pipes and released lead into the water supply. But the evening before officials took their samples, they flushed water from the lines. It’s a practice that’s discouraged but not banned by the EPA. Flint residents found contamination by sampling from unflushed lines — the same way consumers drink water.

Even this method isn’t perfect. It requires sampling the first liter of water that flows out of a tap after a stagnation period — in other words, the fluid near the faucet. But according to a new study, the results look much different when the sample comes from water sitting in a lead service line . Using this approach, 50 to 70 percent of utilities with lead service lines would exceed the EPA’s standard, and nationwide, up to 96 million consumers currently being told that their tap water is safe would need to be informed about potential contamination, according to figures from the American Water Works Association. No wonder that even Michigan Gov. Rick Snyder now says the Lead and Copper Rule is “geared to allow utilities to comply.”

3. Testing proves that your water is safe.

“If you are concerned about lead in your water, you may wish to have your water tested,” the EPA recommends, implying that water is safe if it tests below the 15 parts per billion standard. Testing can reveal high lead levels and confirm contamination. But when it shows little or no lead, it doesn’t mean there’s not a problem.

The release of lead from plumbing can be sporadic. As a result, the way drinking water is usually sampled — by collecting one liter and sending it off to a lab — can miss high concentrations of lead not present at the time and offer false assurance.

As Rebecca Renner wrote for the journal Environmental Health Perspectives, in 2006, officials in Durham, N.C., where tap water had passed EPA compliance monitoring, “linked [a] child’s poisoning to drinking water after they found more than 800 ppb lead in his tap water as a result of corroded solder. No other sources of lead were found in the child’s home.” How could this have happened? The water utility and the health department used different sampling techniques. The utility removed the mesh screen from the faucet before collecting fluid. The health department, by contrast, left the screen in place; because that screen “shredded off tiny bits of lead much the way a grater shreds cheese,” this sample was much more toxic. Many studies have similar findings.

One way to decrease the risk of this type of contamination is to use filters certified to remove lead at the point where it emerges from your faucet.

4. It’s safe to partially replace lead pipes.

If you find out that your residence is connected to a lead service line, the EPA’s 2000 guidance says, “Partial removal of a LSL will reduce the likelihood of exposure to lead from drinking water because there will be a smaller volume of water in contact with the LSL.” Doing something, supposedly, is better than nothing.

But multiple studies show that replacing only part of a lead service line can result in lead spikes for days, weeks, months and even years after the disruption. A repair can make the situation worse. Children in homes with partially replaced lines were twice as likely as children in homes with intact lines to have elevated blood lead levels, according to a 2011 CDC study in Washington . Partial lead line replacements should be viewed as a serious public health risk and banned.

5. Flint’s crisis is all about children.

Mona Hanna-Attisha, the hero pediatrician who helped bring Flint’s story to light, emphasizes that “pediatricians know lead,” and she says it’s imperative for all children in Flint under age 6 to be evaluated for lead poisoning. Irwin Redlener, president of the Children’s Health Fund, has argued that “we need to resettle the children of Flint.” There’s broad consensus that protecting kids is the priority.

Yet as the World Health Organization puts it, “There is no known level of lead exposure that is considered safe” — for anyone. Chronic lead exposure can cause high blood pressure, heart disease, reduced fertility, kidney damage and even cataracts in men and women.

Adults who work in fields where direct exposure to lead is more common, such as lead battery recycling, auto repair and various types of construction work, are at higher risk. But in general, given the reduced likelihood of hand-mouth ingestion that often happens among children, adult exposure is more likely to come from water than from lead dust or paint. And adult lead ingestion can ultimately harm children: Pregnant women, in particular, may experience miscarriage, stillbirth and other adverse outcomes.

outlook@washpost.com

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