Constant claims, counterclaims and accusations about coal ash contaminating surface and underground water are making North Carolinians feel like they’re watching a fast-paced tennis match. Even people with chemistry degrees must feel bewildered by assertions that parts per million or billion of chromium-6 may cause cancer.
Not long ago, scientific instruments couldn’t even detect parts per billion (ppb). That’s not surprising, since 1 ppb is equivalent to 1 second in 33 years or 50 drops of water in an official Olympic-sized swimming pool (50 by 25 by 2 meters – 2 teaspoons in 660,000 gallons).
Carcinogenic toxins in fruits and vegetables help them combat viruses and insect pests, Oakland Research Institute senior scientist Bruce Ames points out. Coffee and tea also contain carcinogens, and numerous chemicals associated with industrial processes (lead, zinc, mercury, chromium and others) are also found naturally in soils, rocks and waters all around us.
Those fruit, veggie and beverage toxins cause cancer in rodents, when fed in large doses.
Apple seeds and juice contain arsenic (about 8 ppb in juice). 80 milligrams (mg) of aspirin can help prevent strokes, and 650 mg can relieve headaches; but 4,000 mg in 24 hours can be toxic, and 100 regular strength tablets can kill a 150-pound adult.
Even swallowing seawater can be deadly. So can guzzling 1.6 gallons of pure water.
For North Carolinians, the relevant question is: What level of chromium-6 (Cr-6 or hexavalent chromium) is safe in drinking water?
State toxicologist Kenneth Rudo says levels detected in state waters represent risks higher than what many public health experts consider safe. He also says there is “no safe level” for exposure to a “geotoxic carcinogen” like Cr-6. He wants the state to retain a 0.07 ppb threshold level, which he says represents a maximum acceptable adult lifetime cancer risk of one in one million.
He persuaded the state to issue “do not drink” letters for people who were using water from wells near Duke Energy coal ash disposal sites.
Other experts disagree, noting that there clearly are safe levels for most chemicals and radiation. Indeed, many are essential for human health or beneficial in warding off cancer and other diseases.
Many peer-reviewed studies support chromium-6 levels at least as high as North Carolina’s dual standard of 10 ppb for well water and 100 ppb for drinking water. The U.S. Environmental Protection Agency also sets 100 ppb for drinking water and says airborne Cr-6 is more worrisome than waterborne varieties.
No one else uses a 0.07 standard, equal to 3.5 drops in an Olympic pool or 1 second in 467 years. Even ultra-cautious California sets its standard at 10 ppb, though some want it reduced to 0.06 ppb.
Equally important, ability to detect a substance does not mean it poses a risk. Cancer is certainly scary, but the risk of getting cancer is not the same as dying from it. And people routinely accept risks of dying from activities they engage in daily.
The National Safety Council puts the lifetime risk of dying in a motor vehicle crash at 1 in 113. That’s 8,850 times greater than Mr. Rudo’s lifetime risk of contracting cancer from Cr-6. The lifetime risk of dying from a lightning strike is 1 in 136,011 – while the risk of dying next year from accidental drowning or strangulation is roughly equal to the Rudo lifetime risk of getting cancer from chromium in water.
In 2015, the NC Department of Environmental Quality tested 24 wells located two to five miles from the nearest coal plant or coal ash deposit. Twenty of those wells received “do not drink” advisories, because their Cr-6 levels exceeded Rudo-recommended thresholds.
Citing those tests and further examination of relevant scientific studies, state Health Director Randall Williams, MD later decided the advisories should be rescinded. Cr-6 levels in wells far from coal facilities mean naturally occurring chromium affects water all around North Carolina, and risks associated with drinking the water are actually low, he noted.
Williams also pointed out that chromium-6 is found in some 70% of all water supplies in the United States. Telling millions of people not to drink their water makes little sense, nor does holding several hundred North Carolina well owners to a standard that applies virtually nowhere else – or holding NC well water to a much stricter standard than drinking water.
Forcing utility companies to spend billions relocating coal ash would shut down many coal-fired power plants. That would send electricity prices soaring and severely impact factories, hospitals, schools, poor families and others. Workers would be laid off or forced to take multiple lower-paying part-time jobs.
That would bring greater stress and depression, reduced nutrition, sleep deprivation, greater alcohol, drug, spousal and child abuse, and higher suicide, stroke, heart attack and cancer rates. It would mean every life theoretically saved by shutting down those plants is offset by real lives lost as a result.
The nationwide lesson is simple. Chromium risks are not as simple or dire as people have been hearing – and hazards associated with eliminating coal-based electricity are likely to be far more serious and widespread.
This article originally appeared in The Washington Times