Poisons and Policy: Arsenic and Aflatoxins
Sep20

Poisons and Policy: Arsenic and Aflatoxins

In the past 24 hours, do you recall hearing anything about arsenic in rice? If you're in the United States, the answer is very likely, "yes!" A great many pixels were spilled yesterday when Consumer Reports and the US Food and Drug Administration released -- almost simultaneously -- analytical data on inorganic arsenic concentrations in 200 samples of commercial rice products, particularly those grown in the southern US. You can't do any better in understanding this story than reading, "Arsenic and Rice. Yes, again," on Deborah Blum's Elemental blog at Wired Science Blogs. Professor Blum has been discussing arsenic in the diet for a few years, an interest she developed while composing her superb book, The Poisoner's Handbook: Murder and the Birth of Forensic Science in Jazz Age New York. Deborah's post puts in perspective the risks of inorganic (and organic) arsenic concentrations in food products such as rice relative to drinking water. Arsenic occurs in nature but exists in higher concentrations in water from areas where arsenical pesticides have been used in cotton farming or poultry deworming (the latter discussed in 2006 at NYTimes). While she closes in being critical of the FDA for lack of clear consumer guidance, let it suffice to say that no character in Blum's book was killed by poisoning with rice from Louisiana. Pick your poison What caught my attention yesterday was a completely different report from the US FDA -- actually a FDA ruling released by the Iowa Department of Agriculture and Land Stewardship. Corn containing one of the most potent natural toxins and carcinogens -- a class of compounds called aflatoxins -- can be legally blended with other corn for use in animal feed.  A standing rule of the FDA, when invoked, allows farmers to blend corn containing up to 20 parts per billion of aflatoxins with corn containing lower concentrations (or none) of the toxin family. Here's where 20 parts per billion falls in the FDA's guidelines according to the Iowa Dept of Agriculture statement: The FDA has established guidelines for acceptable aflatoxin levels in corn based on its intended use.  Corn containing aflatoxin in concentrations of greater than 20 ppb cannot be used for human consumption and cannot be used for feed for dairy animals or for immature livestock of others species. Corn containing aflatoxin at 100 ppb or less can be used in breeding cattle and swine and mature poultry.  Corn with 200 ppb or less can be used with finishing swine greater than 100 lbs. in weight and corn with 300 ppb or less can be used in finishing beef cattle. Where is this aflatoxin coming from...

Read More