While most of us try limit our arsenic exposure to Agatha Christie novels or classic Cary Grant movies, a new study conducted by Consumer Reports suggests we may be getting more arsenic than we think—thanks to fruit juice and, more specifically, apple juice. Why, you may ask, would there be arsenic in apple juice? The chemical element arsenic—known by the symbol As and atomic number 33 to us Periodic Table fans—is a metalloid (a term that refers to materials that have the properties of both metals and non-metals) that’s been known since the days of Aristotle, although the first authentic identification of it was in 1649 by German pharmacist Johann Schroeder. Arsenic occurs naturally in the environment; it’s an element, after all, and erosion of rocks releases it into the environment. (It is found in amounts of 2 to 5 parts per million (ppm) in the Earth’s crust.) Human activities also help spread the love. Arsenic is often used in metallurgy, primarily to harden lead alloys, as well as improve corrosion resistance and thermal properties of copper and brass. It is also used in the semiconductor industry. Oh, and arsenic has a long, colorful history as a poison: in ancient Rome, arsenic-laced figs were weapons of choice for assassins and spurned spouses (ever seen I, Claudius?). It is also believed that Napoleon died of arsenic poisoning while exiled on the island of St. Helena, although whether that was deliberate or accidental remains open to debate—in fact, it’s even been shown that Napoleon (among many others) may have experienced a lifetime of arsenic exposure. German chemist Robert Bunsen—whose eponymous “burner” is familiar to anyone who ever took high school chemistry—had a particular fascination for arsenic, and while heating a beaker of the stuff one day, it blew up and nearly took out his eye leaving him half blind. (See, for example, the endlessly fascinating book The Disappearing Spoon And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements by Sam Kean.) But I digress... Arsenic is also used as a wood preserver (thanks to its toxicity to insects and other pests), and for many years was used in insecticides. It’s also been added to poultry and pig feed to control lice and ticks—yum! Arsenic is found in both organic and inorganic forms, which adds to much of the confusion about our friend Element 33. Organic arsenic, as you would expect, exists in compounds that also include carbon (and often hydrogen). Organic arsenic compounds are generally deemed harmless per se, but their ability to break down and form far more toxic inorganic arsenic compounds has led to restrictions on the agricultural use of organic arsenic compounds. In some parts of the world, arsenic contamination of groundwater has led to outbreaks of arsenic poisoning. A 2002 study published in the journal Applied Geochemistry found that “over 137 million people in more than 70 countries are probably affected by arsenic poisoning of drinking water.” Although much arsenic use has been banned, at least in the U.S., it’s largely the legacy use of arsenic that has led to its turning up in fruits and, ergo, juices. Arsenic-based insecticides used on orchards and vineyards (whence apples and grapes) has been curtailed, but the compounds linger in the soil. And when old arsenic-treated wood is mulched, arsenic leaches into the ground. While there is no direct regulation on arsenic in beverages like apple juice, the FDA does have a “level of concern” of 23 parts per billion (ppb); that is, “the chronic consumption of apple juice products containing over 23 µg/L (ppb) inorganic arsenic would represent a potential health risk.” The EPA, on the other hand, “changed the water standard for arsenic to 10 ppb, effective in 2006, from the 50-ppb limit it set in 1975. The EPA had proposed a 5-ppb limit in 2000, so the current limit is a compromise that came only after years of haggling over the costs of removing arsenic.” Back to the Consumer Reports study. What did they test and what did they find?

We went shopping in Connecticut, New Jersey, and New York in August and September, buying 28 apple juices and three grape juices. Our samples came from ready-to-drink bottles, juice boxes, and cans of concentrate. For most juices, we bought three different lot numbers to assess variability. (For some juices, we couldn’t find three lots, so we tested one or two.) In all, we tested 88 samples. Five samples of apple juice and four of grape juice had total arsenic levels exceeding the 10 ppb federal limit for bottled and drinking water. Levels in the apple juices ranged from 1.1 to 13.9 ppb, and grape-juice levels were even higher, 5.9 to 24.7 ppb. Most of the total arsenic in our samples was inorganic, our tests showed. As for lead, about one fourth of all juice samples had levels at or above the 5-ppb limit for bottled water. The top lead level for apple juice was 13.6 ppb; for grape juice, 15.9 ppb.

Furthermore, are juice drinkers more greatly exposed to arsenic than non-juice drinkers?

The resulting analysis of almost 3,000 study participants found that those reporting apple-juice consumption had on average 19 percent greater levels of total urinary arsenic than those subjects who did not, and those who reported drinking grape juice had 20 percent higher levels. The results might understate the correlation between juice consumption and urinary arsenic levels because NHANES urinary data exclude children younger than 6, who tend to be big juice drinkers.

Although we typically think of arsenic poisoning as something that happens in one fell swoop or at the very least over a short period of time, usually before Hercule Poirot shows up, cumulative exposure to small amounts of the metalloid have been linked to impaired cognitive functioning. The analogy is lead poisoning. However, the problem may not be with arsenic in our own backyard. Continues CR:

Over the years, a shift has occurred in how juice sold in America is produced. To make apple juice, manufacturers often blend water with apple-juice concentrate from multiple sources. For the past decade, most concentrate has come from China (PDF). Concerns have been raised about the possible continuing use of arsenical pesticides there, and several Chinese provinces that are primary apple-growing regions are known to have high arsenic concentrations in groundwater. A much bigger test than ours would be needed to establish any correlation between elevated arsenic or lead levels and the juice concentrate’s country of origin.

CR calls for stricter (or any) regulations on arsenic in juices. It also advises homeowners whose water comes from private wells to test their water for arsenic (public utilities are required to treat arsenic-laden water). On the plus side, there are some bacteria that have been found to use arsenic as part of its basic biochemistry.