There’s been a lot of chatter about the arsenic-in-apple-juice debacle involving TV’s Dr. Mehmet Oz, the FDA and Consumer Reports. If you don’t know the backstory, fellow PLoS blogger Deborah Blum has written two great posts about it, which you can find here and here.
I only have one thing to add. I’ve heard some people react to the Consumer Reports findings with comments like, “well, most of the arsenic levels were at or below the EPA’s limit for drinking water, so it can’t be that bad.” But for this to be true, the EPA’s arsenic limit has to be adequately protecting the public. I don’t think it is.
The Environmental Protection Agency, which regulates drinking water, considers arsenic a class A carcinogen, meaning that data have definitively shown it to cause cancer. Other health effects from chronic low-level exposure include partial paralysis, blindness and diabetes. Although the EPA tightened its regulations for arsenic levels in drinking water this past January , lowering it from a maximum of 50 parts per billion (ppb) to 10 ppb, this new level still exceeds the agency’s recommendations for exposure to a carcinogen by a factor of 50.
The EPA typically recommends that the amount of a carcinogen in drinking water should not cause more than one person in 100,000 to develop cancer as a result of drinking that water daily. But Americans who are regularly drinking water containing 10 ppb of arsenic are at a 50-fold higher cancer risk than this: in other words, one out of every 2,000 of those Americans is likely to develop cancer because of the arsenic in their tap water. And the EPA estimates that 12 million Americans are currently drinking water containing more than 10 ppb of arsenic—making their cancer risk even higher.
The EPA isn’t meeting its own safety standard for arsenic because the recommended amounts “are set at a level which water systems cannot meet,” according to agency press officer Dale Kemery. After preparing a cost / benefit analysis, the EPA set its arsenic limits at a level that maximized risk reduction while minimizing cost to the consumer, he says.
If you’re curious about the math, the EPA provides data here (scroll down to “Quantitative Estimate of Carcinogenic Risk from Oral Exposure”) showing that water arsenic levels would need to be 0.2 µg/L, or 0.2 ppb, for only one in 100,000 people to develop cancer from chronic exposure. And 10 ppb is 50 times greater than 0.2 ppb.
My point is not that we should all be freaking out about the arsenic in apple juice. I haven’t spent a lot of time investigating the issue, and of course, most Americans drink far less apple juice than they do tap water. But I do think it’s important for people to realize that when they compare exposures to agency limits, the latter may not be as protective as they think.