Arsenic In Apple Juice - How Come?
HuffPo recently covered an article by Consumer Reports indicating total arsenic concentrations in fruit juices that stray above drinking water limits. People reading HuffPo coverage are left with no explanation as to how arsenic got in juice which is a favorite for kids, whether it was dissolved or associated with particulate matter, whether organic juice had comparable levels of arsenic, etc. Leaving consumers without this and related exposure information increases the likelihood they just ignore the findings -- an unfortunate upshot of poor risk communication by people with good intentions. More on that below.
The arsenic concentration in fruit juice is meaningless unless the data are ipresented in context of a "market basket" concentrations: i..e. average concentration of all foods found in a balanced diet; plus, the concentrations in specific foods in that diet. USEPA and FDA have prepared so-called "market basket exposure studies" which offer this information.
China, of course.
Most of the clear, bottled apple juice you see in the beverage aisle of the grocery came from China - indirectly. The Chinese filter it (no doubt it is pretty brown after picking up the buggy ones on the ground, etc) concentrated it and send the concentrate to US bottlers.
Be glad for EPA.
Before the USEPA was around, there were some nasty arsenic mixtures used as pesticides or herbicides in the USA. WIkipedia has a brief explanation: "Calcium arsenate (Ca3(AsO4)2) is an extremely poisonous chemical compound that most commonly exists as a colorless to white amorphous solid. It was originally used as a pesticide and as a germicide. It is highly soluble in water, as compared with lead arsenate, which makes it more toxic."
Note the reference to use of lead arsenate. The Wikipedia entry on that one is worth reading at length as the use on apples and orchards is explained. Here are the highlights you should focus on, however.
Lead arsenate was the most extensively used arsenical insecticide....Until 1930s-1940s, lead arsenate was frequently prepared by farmers at home, by reacting soluble lead salts with sodium arsenate...It was used mainly on apples, but also on other fruit trees, garden crops, turfgrasses, and against mosquitoes. ...The search for a substitute was commenced in 1919, when it was found that its residues remain in the products despite washing their surfaces. Alternatives were found to be less effective or more toxic to plants and animals, until 1947 when DDT was found. The use of lead arsenate in the USA continued until the mid-1960s. It was officially banned as an insecticide on August 1, 1988.
Why would fruit juices from China have high arsenic?
China's air is awash in arsenic and lead from the profligate use of coal. Heavy metals sent up coal stacks fall onto plants and soil as particulate matter or are dissolved in rain before they precipitate on plants and soil. Plus, there is a chance they are using arsenic as a pesticide - a practice common in the West 30 to 40 years ago but no longer allowed.
The primary source cited by HuffPo was a Consumer Reports article. An earlier Consumer Reports article on the same topic explained that in China:
“Lead arsenate is probably still being used illegally there, and was used widely I think even after 2000,” says Charles Benbrook, PhD, who worked for more than 20 years in Washington, D.C., on agricultural policy issues including pesticide regulation and now serves as chief scientist at The Organic Center, a research institute. China also is the world’s largest producer of arsenic and arsenic compounds, according to a 2008 report from the U.S. Geological Survey.
Market basket studies.
As for the market basket studies I mentioned, Consumer Reports did a limited on on juices (at the first link above). You can get a peek at a diverse one here.
Here's another just on US produced rice
Here's an overview of the FDA's Total Dietary Exposure study which refers to arsenic exposures from meat fed contaminated carrots that had been treated with lead arsenate.
But the study you really want to read is the excellent one on childhood arsenic exposure by USEPA - the very EPA Norquist-style Republicans want to get rid of - (via: Hum. Ecol. Risk Assess. Vol. 10, No. 3, 2004; and presented here as pdf file download) from which I excerpted the following table.
This table better than any philosophical argument demonstrates clearly that unless you see the other routes of food exposure in context it amounts to very poor risk communication.