30280: Leiderman (followup): rice that Haitians eat (fwd)

[Bob Corbett <corbetre@webster.edu>]

From: leiderman@mindspring.com


29 March 2007

dear Readers, re posts 30275, 30260, 30251 and 30243:

thanks to Philippe Charles for his followup about arsenic in rice, especially about export-import oversight and the potentially higher economic and health value of of Haitian varieties if they prove to be less-contaminated than American varieties, or not contaminated at all.  at the moment, I do not have information on arsenic levels in American rice going to Haiti, or of Haitian rice going to the US, or whether and how the two governments test for arsenic.

the scientist from Scotland who found high levels of arsenic in American rice wrote me that he is ready to test Haitian rice, so the task is to collect a variety of different samples (natural, polished, plain white, enriched, short-grain, long-grain, sweet, etc.) as can be found in Haiti, including both native-grown and imported.  Corbett readers and their friends and families can be a big help in locating, identifying and suggesting samples from the countryside, marketplaces, stores, restaurants, hotels, schools, etc.  personally, I'm particularly interested in rice that is being distributed in government, school and charitable feeding programs.

soon, I'll write up and post brief instructions on collecting, identifying, packaging and sending samples -- the geographical location, method of growing, processing, packing, etc. will help identify the varieties.  we'll use a "split sample" method so that identical portions are kept under lock and key for safe keeping and re-testing if necessary.

this kind of investigation is perfect for the sharp eyes and minds of college-level Haitian science and medical students and their teachers.  I'll be happy to hear from any who want to participate.  for information, the basic analytical method is reprinted below.

thank you,

Stuart Leiderman
leiderman@mindspring.com

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From: Philippe Charles <pgcharles@optonline.net>

<snip> It's easy to guess that if there were high levels of arsenic in Haitian rice then the FDA would not have allowed its import into the US.

<snip> ...a silver lining in this situation. Once Prof. Meharg has
proved that Haitian rice does not contain high levels of arsenic, the Haitian rice growers can start charging a premium for their "clean" rice.

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Arsenic Testing Method, in:
http://pubs.acs.org/cgi-bin/sample.cgi/esthag/2007/41/i07/html/es061489k.html

Total Element Detection. An Agilent 7500c (Agilent Technologies, Toyoko, Japan) octopole reaction system (ORS)-ICP-MS, with a Meinhard nebulizer, was used to measure the elements. Further details are provided in the Supporting Information. The limits of detection for As and Se were 77 ng As L-1 and 79 ng Se L-1. This is equivalent to a level in rice of 0.019 g As g-1 and 0.020 g Se g-1, assuming sample weights of 0.2 g are maintained. Limits of detection for the other
elements are reported in Table S15, in the Supporting Information. NIST Certified Reference Material (CRM) 1568a Arkansas long grain rice flour was used to validate the analysis. The average CRM recovery for all the elements was 94 Â 5%. As CRM recovery was 112 Â 1.2%. Se CRM recovery was 96 Â 1.2%. Spike recoveries for As and Se were 90 Â 0.0% and 76 Â 1.8%, respectively. CRM and spike recoveries for the other elements are reported in Table S15, in the Supporting Information. The presented data have not been corrected for these recoveries.