Correspondence/Rebuttal pubs.acs.org/est
Comment on “Feather Meal: A previously Unrecognized Route for Reentry into the Food Supply of Multiple Pharmaceuticals and Personal Care Products (PPCPs)”
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where there is essentially no poultry production. These sample sites would not be representative of places where feather meals are typically produced and geographically unrepresentative of annual broiler production in the U.S. This scheme is numerically inadequate to make any meaningful inferences about the much larger quantities produced annually in the US. Additionally, 95−98% all of the rendered feather meal produced in the U.S. is used as a pet food ingredient or as a ruminant bypass protein.3 Only a very small portion of the feather meal produced is fed back in poultry rations and only after it has been carefully analyzed for pesticides and heavy metals.3 Feather meals are produced by high pressure and temperature cooking, followed by pressing, drying and grinding to make the amino acids bioavailable. In many areas the municipal waters added to the feathers to initiate the cooking process contain trace amounts of the types of pharmaceuticals found in this paper. Low level water contamination combined with high temperature and pressure cooking could easily account for the results reported to be from the feathers. Pharmaceuticals, antimicrobials (including fluoroquinolones), and caffeine are commonly found in water treatment plant effluents.4 In this case, there would be no need to worry about feather meal as a “reentry route” because water would much more easily serve as a direct entry route. Why this article does not discuss treated municipal waters as a potential source for contamination of domestic feather meals seems obvious by its absence. The anecdotal evidence (from Supporting Information box S1) cited to support clandestine use of illegal pharmaceuticals is unsupportable as it relates to integrated poultry production. Contract poultry growers provide only the housing and husbandry to produce market broilers, the integrated poultry companies for whom they grow own the birds and dictate the feed and medications that go into each flock by contractual agreement. Any suggestion that a company would risk a felony conviction (or a grower his contract) to use an unapproved or outlawed product (i.e., fluoroquinolone, stimulant, hormone, or sedative) is simply not plausible. My poultry practitioner colleagues and I find the suggestion that there may be continuous and systematic illegal use of unapproved drugs in commercial poultry to be unsubstantiated by any scientific evidence. We suggest that admixture with imported feather meals or municipal water source contamination is the more likely route by which feather meals might show low level drug residuals.
ome initial clarifications and corrections to this article are worth mentioning. Turkey production in the United States is approximately 250 million head per year versus the 80 million cited in this article. A recent publication by Apley et al.2 documents that only about 15% of all antibiotic use in swine production is used specifically for growth promotion. This undergirds the fact that antibiotics are not used primarily for growth promotion but for treatment and prevention of clinical disease outbreaks. Antibiotic use in commercial poultry production is further reduced from that in swine production. Finally, there appears to be a disconnect between the sample collections reported in the “Methods” section versus those reported in Table 1. A North Carolina (NC) sample is mentioned in methods (a Pennsylvania (PA) sample is not), whereas a PA sample is reported on in Table 1 and the NC sample mentioned is missing. Seven of the 12 samples analyzed in this publication were described as “fertilizer”. This suggests that nearly 60% of the data presented in the paper pertains to product that is primarily destined to become soil amendment and not animal feedstuffs as they are mixed with manure to produce organic fertilizers. As a result, this product should not be considered a “reentry route” into the food supply because (1) No data on its ultimate incorporation into field crops or produce destined for the grocery store are provided and (2) No data on its incorporation into point-of-purchase animal protein has been demonstrated for any animals fed any amount of feather meal fertilized corn, sorghum grain, or soybean meal. Without usage data, bioavailability figures, and proof of end product incorporation the ability of feather meal to serve as a reentry route cannot be supported. Most of the chemical products considered to be reentry candidates are found only at or near their limits of detection. Only three feather meal samples (25%) analyzed are potentially relevant to practices of animal feeding in the United States; two are from imported samples originating in China. It does not seem logical to analyze imported feather meal when the U.S. industry is clearly a net exporter of feather meal. The U.S. is reported in the article to have an annual production capacity of 2.0 billion Kgs and only 0.5 Kgs are used domestically. Roughly 75% of the feather meal produced is unaccounted for. It appears that we necessarily remain net exporters rather than importers of feather meal. A fundamental tenet for making any inferences from a sample subset to a population at large is that the sampling technique is both adequate in size and randomly obtained if it is to be representative of the larger population for purposes of statistical inference. No rationale is provided as to why only 7.5 gms (in the case of U.S. feather meal for animal feed; three samples consisting of 2.5 gms each taken from larger 200 g samples)1 were used to make inferences about 0.5 billion Kgs of domestically produced feather meal. Two of these three samples were obtained from states (Oregon and Idaho) © 2012 American Chemical Society
Mark Bland American Association of Avian Pathologists, 12627 San Jose Boulevard, Suite 202, Jacksonville, Florida, 32223 Published: October 29, 2012 13555
dx.doi.org/10.1021/es303510z | Environ. Sci. Technol. 2012, 46, 13555−13556
Environmental Science & Technology
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Correspondence/Rebuttal
AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. Notes
The authors declare no competing financial interest.
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REFERENCES
(1) Love, D. C.; Halden, R. U.; Davis, M. F.; Nachman, K. E. Feather meal: A previously unrecognized route for reentry into the food supply of multiple pharmaceuticals and personal care products (PPCPs). Environ. Sci. Technol. 2012, 46 (7), 3795−3802. (2) Apley, M. D.; Bush, E. J.; Morrison, R. B.; Singer, R. S.; Snelson, H. Use estimates of in-feed antimicrobials in swine production in the United States. Foodborne Pathog. Dis. 2012, 9 (3), 1−8. (3) Personal Communication. Foster Farms. Livingston, CA. 2012 (4) Kolpin, D. W.; Furlong, E. T.; Meyer, M. T.; Thurman, E. M.; Zaugg, S. D.; Barber, L. B.; Buxton, H. T. Pharmaceuticals, hormones and other organic wastewater contaminants in U.S. streams, 1999− 2000: A national reconnaisance. Environ. Sci. Technol. 2002, 36 (6), 1202−1211.
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dx.doi.org/10.1021/es303510z | Environ. Sci. Technol. 2012, 46, 13555−13556
