This post was researched and written by our bright, young summer intern, Sasha M.
In today’s media-thick world, an issue that comes up with surprising infrequence is biosecurity. Perhaps this is related to the fact that spell-check just came up to tell me it wasn’t a word. But Webster-compliant or not, biosecurity is a real issue in America. There are critical flaws in our ability to protect our citizens from biological attack, perhaps the most vulnerable area of which is our crops.
American farmers have achieved massive yields of food through monoculture, where thousands of adjacent acres of a genetically identical crop are grown. However, a single disease to which the crop is vulnerable can easily destroy it all. Wheat rust, particularly race Ug99, is currently spreading all over the world and destroying cereal crops (1). It is quickly spreading thanks to large, monoculture-practicing fields (2). Weapons have also been developed specifically to spread wheat rust and cripple agriculture, which could prove deadly (3).
Also, these large groups of crops are often grown with pesticides, which can prove to be a problem. If a disease survives a particular pesticide due to a particular genetic mutation, its offspring will carry that resistance and proliferate. The disease can now easily infect previously immune crops, which the use of monoculture assists. Whether the disease is natural, or intentionally released for terrorism, monoculture-grown crops are a great weakness as they allow for easier transmission and destruction.
A similar situation is occurring in the cattle industry. Cattle are often fed an unnaturally high-starch diet, which can consist of up to 90% corn, while they would eat almost exclusively grass in the wild. This starch causes a disease of the rumen, which results in the production of excess acid. E. Coli naturally live in cattle’s digestive tracts, and those that survive the reduced pH will produce acid-resistant offspring, who can bypass the human stomach’s defenses and cause infection. The increased acid can also cause ulcers, which lead to infections that require intense antibiotic treatment. Not only does this hurt the animals, but antibiotic traces can also be passed on to humans (4). This widespread usage of antibiotics can promote the growth of antibiotic resistant bacteria, which can affect the treatment of both cattle and human diseases. In large feedlots, large amounts of waste are produced, which can potentially carry E. Coli. Cattle are often exposed to this waste, and as a result their meat may contain E. Coli. Annually, the strain O157:H7 causes an average of 61 deaths and over 70,000 illnesses (5) and is resistant to numerous climactic conditions such as acid (6), soil and fresh water (7). An infection with this strain is in fact made temporarily worse by antibiotics, since once it is killed it may release large quantities of Shiga toxins (8).
We Americans need to change the way we look at food. While grain-fed beef can contain the more harmful strains of E. Coli, grass-fed beef, in which cattle are fully raised in pastures, has been shown to contain fewer and less acid-resistant ones, as well as requiring little to no antibiotics (9). Additionally, crops can be planted in diverse configurations, to prevent the easy spread of disease. And a more conscious anti-pest system, like Integrated Pest Management, could be used along with genetically modified or hybridized crops with greater resistances instead of pesticides. Making changes for our biosecurity will be an investment, but it will prove to be worth it.
1) http://www.ars.usda.gov/Main/docs.htm?docid=14649- Ugandan wheat rust species Ug99
2) CIMMYT report: Impacts of International Wheat Breeding Research in Developing Countries, 1966-97
3) Wheelis, Mark, et al. Deadly Cultures: Biological Weapons Since 1945, (Google Books), Harvard University Press, 2006, pp. 217-18, (ISBN 0674016998).
4) Schlosser, Eric, “Fast Food Nation”, 2001
5) Mead et al., “Food-Related Illness and Death”
6) Diez-Gonzalez, F. et al. 1998. Grain feeding and the dissemination of acid-resistant Escherichia coli from cattle. Science 281:1666-1668. (See also Science April 2, 1999 for a debate of the results of this paper.)
7) http://aem.asm.org/cgi/content/full/68/1/397?ijkey=yieYQKQlwqJlg&keytype=ref&siteid=asmjournals%20 – a study of E. Coli penetrating vegetables through water and soil
8 ) http://onlinelibrary.wiley.com/doi/10.1111/j.1432-1033.1988.tb13756.x/abstract -a study of toxins produced by E. Coli. See also “Fast Food Nation”, above
9) Pollan, Michael. 2002. This Steer’s Life. The New York Times Magazine March 31: 44-