Lead in cocoa and chocolate: Rankin and Flegal respond.
Because the concentration measurements indicated that this contamination was not naturally derived, we analyzed other materials for lead concentrations and lead isotopic composition to determine possible sources of the increase in lead in cocoa products. We are unsure about the origination of additional points in Figures 2 and 4, but we used the data listed in Table 3 in forming our original conclusions, and we continue to support those conclusions. To suggest, as Manton does, that the lead isotopic composition measurements show that the contamination is naturally derived is disingenuous and inconsistent with the extensive literature using lead isotopic compositions to characterize potential sources--natural and industrial--of lead in the biosphere (Cocoa Producers' Alliance 2004; National Research Council 1993). We maintain that the lead isotopic composition measurements suggest that, although it may be possible for some contamination originating at the cocoa farms to be transferred to the final products, the majority of contamination must accumulate during shipping and/or manufacturing, as both the lead concentrations and lead isotopic compositions of cocoa and chocolate products indicate.
Finally, we are disappointed with Manton's comment regarding our declaration of no competing financial interests. In our article (Rankin et al. 2005), we listed the American Environmental Safety Institute (AESI) as a source of funding. The institute provided some of the funding for the chemical analyses, scientific interpretation, and litigation depositions, but these were all done with the agreement that our study would be equipoised--conducted without bias. Moreover, the litigation was settled well before our manuscript was written, and we neither received nor requested funding from the AESI or any other organization or any individual involved in the litigation for the preparation or publication of the article.
The authors declare they have no competing financial interests.
Cocoa Producers' Alliance. 2004. Proposed Methodology to Determine Source and Level of Lead Contamination in Cocoa. Available: http://www.copal-cpa.org/lead.html [accessed 26 January 2006].
National Research Council. 1993. Measuring Lead Exposure in Infants, Children end Other Sensitive Populations. Washington, DC:National Academy Press.
Rankin CW, Nriagu JO, Aggarwal JK, Arowolo TA, Adebayo K, Flegal AR. 2005. Lead contamination in cocoa and cocoa products: isotopic evidence of global contamination. Environ Health Perspect 113:1344-1348.
Charley W. Rankin
A. Russell Flegal
Environmental Toxicology, WIGS,
University of California, Santa Cruz
Santa Cruz, California
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|Title Annotation:||Perspectives: Correspondence|
|Author:||Flegal, A. Russell|
|Publication:||Environmental Health Perspectives|
|Date:||May 1, 2006|
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