Bt Cotton Is Harmful to Organic Agriculture and the Environment:
Comments of the Organic Trade Association to the Environmental Protection Agency on
Docket Number OPP-2003-0331
Tom Hutcheson, Associate Policy Director
Organic Trade Association
November 14, 2003
The Organic Trade Association (OTA) has consistently commented to EPA, FDA, and USDA that Bt crops are harmful in many ways to organic agriculture. Organic agriculture uses ecological principles to produce both food and fiber, but the ecology of Bt plants is rarely given independent, peer-reviewed study. The studies that have been independently produced and reviewed raise serious questions about the possible negative ecological effects of genetically engineered organisms.[i], [ii]
Unless solid, independent studies are produced showing evidence to the contrary, especially concerning ecological effects, OTA urges EPA not to approve any further Bt plants, based on 1) the likelihood of insect resistance, leading to direct harm for organic agriculture, is sufficient reason to deny any further petitions for the use of Bt plants; 2) the only known effects of gene flow suggest the inevitable escape of unwanted genes into both wild and domesticated plants, not necessarily of the same species as the donor; and 3) the natural and cultural ineffectiveness of EPA’s current refugia regime due to inadequate buffer zones and lax enforcement.
Bt, when used with care not to stimulate insect resistance, is an excellent biological control for corn and cotton insect pests. In fact, Bt is the most widely used biological control in organic agriculture.[iii] The responsible use of Bt involves large, very short-term doses (typically with insect exposure of less than 48 hours). On the other hand, the nature of bioengineered Bt plants is such that less effective doses are created, over an entire growing season, resulting in the virtual assurance of significant insect resistance. By the time such resistance is created to any of the forms of Bt, the effectiveness of most strains of Bt is likely to be severely compromised, and such signs have already been noted.[iv]
So far, EPA’s attempts to create a resistance strategy based on planting patterns have not resulted in a protocol which is widely accepted as effective. This, combined with the lack of an enforcement program, signals that the use of bioengineered Bt plants will lead quickly to significant insect resistance, depriving organic farmers of one of their most useful tools.
Impending pest resistance to the common Cry1 protein is the primary reason Aventis developed Cry9C StarLink corn.[v] OTA applauds EPA for having expressed the scientific consensus that the safety of the Cry9C protein in the human food chain is in serious doubt. OTA urges EPA to also note publicly that ecological studies have shown reason for concern over the use of Bt crops due to the persistence of the Bt toxin in soil due to root exudates at least as long as eight months after the crop is harvested, and that this extended presence of the active insecticide could affect soil ecology.[vi]
Along with the similarly serious questions about the anomalous expression of fusion genes,[vii] so also must the common use of antibiotic resistance marker genes in Bt plants be addressed. The British Medical Association has stated, “There should be a ban on the use of antibiotic resistance marker genes in GM food, as the risk to public health from antibiotic resistance developing in microorganisms is one of the major public health threats that will be faced in the 21st century.”[viii] The American Medical Association has also expressed concerns: “…the use of antibiotic markers that encode resistance to clinically important antibiotics should be avoided if possible.”[ix]
Given these concerns, at the very least EPA should enact a moratorium on Bt cotton registrations until an independently studied, peer-reviewed method for pest resistance management is ready to be implemented. This moratorium should be extended to all other Bt plants as well. Beyond that, the fact that the few ecological studies that have been done have shown substantial reason for concern should be enough to persuade EPA to enact a moratorium on the commercial use of all Bt plants until sufficient independent, peer-reviewed studies have been done to prove that there are no ecologically harmful effects. These studies would have to provide compelling data on pleiotropic effects, the stability of the transgenic line and the possibility of horizontal gene transfer,[x] pest resistance, impacts on non-target species, and gene flow to wild relatives of both cotton and all other crops for which a Bt form has been developed. Based on the independent research to date, OTA doubts that such compelling data would result.
One recent study has shown than Monarch butterfly larvae may usually be exposed in the field only to non-lethal doses of Bt corn pollen, which is good news for that specie, but this information must also be interpreted as demonstrating the difficulty of implementing an effective insect resistance strategy due to the dispersal of Bt pollen in low doses. Dispersal could become the primary mechanism for creating general insect resistance.
OTA further calls on EPA to coordinate its work thoroughly with FDA and USDA to ensure that the human health, animal health, and environmental and ecological effects are considered comprehensively. This new technology involves whole systems, and it is the joint responsibility of EPA, FDA, USDA, and NIH, at least, to ensure that no issues are left unconsidered.
Lastly, the use of Bt crops has an economic impact on organic production as pollen drift, leading to gene flow, from Bt plants can contaminate non-bioengineered organic crops. Bt contamination is trespass, a nuisance, unwanted, and can lead to significant economic losses for organic farmers. This is a clear example of potentially disastrous environmental degradation, with the added problem that consumers seeking products that contain no genetically engineered materials may be denied this choice because of inadvertent contamination.
[i] A beginning to the ecological study of Bt corn may be found in Obrycki, et al. (2001). Transgeneic Insecticidal Corn: Beyond Insecticidal Toxicity to Ecological Complexity. BioScience, May, 2001. Further research obviously needs to be done before the ecology of Bt plants can be known sufficiently to make an informed decision regarding their use in the field. Among other points EPA may wish to note, the authors of this study report that “Bt plantings are not being used as a replacement for insecticides but in addition to them.” A supposed reduction is pesticide use is therefore not a defensible position for approving such plants, given the reality of Bt plant use in the field.
[ii] Makhijani, A. (2001). Ecology and Genetics: An Essay on the Nature of Life and the Problem of Genetic Engineering. Washington, DC: Institute for Energy and Environmental Research. Makhijani writes in the summary document, “Creating new genomic structures by inter-species genetic engineering would be a very risky proposition under any circumstances, but it is particularly rash in the face of the fundamental gaps in knowledge of how genomic structures express themselves in ecosystems.”
[iii] Walz, Erica. (1999). Final Results of the Third Biennial National Organic Farmers Survey. Santa Cruz: Organic Farming Research Foundation. See p. 80.
[iv] See Cummins, J., No Bt Resistance? http://www.i-sis.org.uk/nobtresistance.php
[v] Macintosh, Susan C. (2001). Unique Attributes of Cry9C (StarLink) Bt Help Assure Long-Term Viability of Bt in Crop Protection. (Aventis white paper). Web document: http://www.us.cropscience.aventis.com/AventisUS/Cropscience/stage/html/whitepapersl.htm
Macintosh writes: “A possible threat to Bt arises from the potential development of insect resistance to Bt. Now, a new Bt protein called Cry9C, marketed as StarLink, can be used to address those concerns because of its unique composition and characteristics.”
[vi] Saxena, D., Flores, S., and Stotzky, G. ( 1999). Transgenic plants: Insecticidal toxin in root exudates from Bt corn. Nature 402: 6761 (December 2, 1999), p. 480.
[vii] Leder, A., Pattengale, P.K., Kuo, A., Stewart, T.A., and Leder, P. (1986). Consequences of widespread deregulation of the c-myc gene in transgenic mice: multiple neoplasms and normal development. Cell, May 23, 1986, pp. 485-495.
[viii] British Medical Association. (1999). The Impact of Genetic Modification on Agriculture, Food, and Health. London: British Medical Association.
[ix] American Medical Association Council on Scientific Affairs. (2001). Genetically Modified Crops and Foods. Chicago: American Medical Association.
[x] Ho, M. W. et al. (1998). Microbial Ecology in Health and Disease 10, pp. 33-59; Ho, M.W., Ryan, A., Cummins, J. (2000). Microbial Ecology in Health and Disease 12, pp. 6-11; Ho, M.W., Steinbrecher, R. (1998). Environmental and Nutritional Interactions 2, pp. 51-84; Windels, P., et al. (2001). Eur Food Res Technol DOI 10.10007/s002170100336.