Risks in the Agricultural System

There are several risks associated with agriculture, particularly of disease and illness.

Zoonotic Diseases

The interface between humans and other animals is the major source of risk for infectious disease. The food system is a major component.

Major causes identified for 335 emerging infectious disease outbreaks from 1940 to 2004. Source: Jones et al. ¹.

Several additional studies have confirmed land use change, driven primarily by agriculture, as the most important source of risk for zoonotic disease ², ³, ⁴, ⁵.

Foodborne Illnesses

Worldwide, foodborne illness cause about 600 million illnesses and 420 thousand deaths each year ⁶. In the United States, illnesses can be attributed to particular foods as follows.

Causes, by type of food, of 4607 foodborne illness outbreaks in the United States from 1998 to 2014. There are an additional 13,596 outbreaks that cannot be attributed to a particular type of food. Caloric intake by type of food is shown for comparison. Source: illness data from Richardson et al. ⁷ and caloric intake data from FAOSTAT ⁸.

Antibiotic Resistance

Antibiotics are one of the great achievements of modern medicine, with an estimated value of $60-300 trillion in the United States alone ⁹. However, this value depletes with usage, since antibiotic usages causes bacteria to evolve with antibiotic resistance. Under current trends, antibiotic resistant bacteria could kill 10 million people per year and lower GDP by 2-3.5% by 2050 ¹⁰. Heavy use of antibiotics in livestock is of particular concern.

Use of antibiotics in the United States, estimated in 2013. Source: Hollis and Ahmed ⁹.

The connection between farm antibiotic usage and antibiotic resistance infections in humans is firmly established ¹¹, though the marginal impact of antibiotic usage is not known with precision. It is estimated that as of 1999, the fluoroquinolone resistance of a specific pathogen, Campylobacter, was responsible for 7 cents of externalized damage per chicken produced ¹², in contrast to a wholesale price of about $2 of meat per chicken. Since then, fluoroquinolone has been effectively banned in chicken production.

Antibiotic overuse in livestock can be addressed by taxation that accounts for the externalized cost of antibiotic resistant bacteria ⁹.

Genetic Risks

With the advent of transgenic crops in particular, there is concern about ecological risks associated with the culivation of genetically modified organisms.

Horizontal gene transfer is the notion that modified genes might transition into the wild environment, causing unpredictable ecological effects. While some authors have called for GM crops to be banned on the basis of this risk, citing the precautionary principle ¹³, ¹⁴, there is little evidence that horizontal transfer is a significant risk ¹⁵.

GM crops have played a role in the spread of herbicide-resistant weeds, and the use of Roundup Ready corn seed may have contributed to loss of bee populations ¹⁶.

Monoculture Risk

Crop monoculture, or the planting of a single variety of crop over a large area and/or for an extended period of time, has been an important driver of high yield and low cost of production ¹⁷.

Monoculture poses a risk of crop disease, which can threaten food security. This phenomenon has been observed, for example, in the context of rice ¹⁸, forestry ¹⁹, and biofuels ²⁰. Historically, increased vulnerability to disease resulting from monoculture production contributed to the blight behind the Irish Potato Famine ²¹ and the Panama Disease outbreak that devastated Gros Michel banana crops in the 1950s ²².