The data-dense graphic above may be too reduced to read (here’s the really big version), but its intricacy masks a simple and fairly dire message: The global trade in food has become so complex that we have almost lost the ability to trace the path of any food sold into the network. And, as a result, we are also about to lose the ability to track any contaminated food, or any product causing foodborne illness.
The graphic, and warning, come from a paper published last week in PLoS ONE by researchers from the United States, United Kingdom, Hungary and Romania. The group used United Nations food-trade data — along with some math that I do not pretend to understand — to describe an “international agro-food trade network” (IFTN) with seven countries at its center, but a dense web of connections with many others. Each of the seven countries, they find, trades with more than 77 percent of all the 207 countries on which the UN gathers information.
As a result, they say: “The IFTN has become a densely interwoven complex network, creating a perfect platform to spread potential contaminants with practically untraceable origins.”
Some background facts: The current trade in food is worth $1.06 trillion, up from $438 billion just 10 years earlier. Food trade, in fact, has been growing faster than food production: Components made multiple trips through the system, becoming ingredients in processed foods that are assembled out of products from all over the globe.
As one example of that complexity, a press release about this study described a chicken Kiev prepared entree served in a Dublin restaurant that was found to contain ingredients from 53 countries. Remember, too, that it took weeks to track down the seeds that were the heart of the massive European E. coli outbreak last summer; when they were finally identified, they turned out to have been moving from country to country, sold and repackaged and sold again, out of a shipment that first left an Egyptian port in 2009.
The effect of that complexity is to unmoor foods from their origins, obscuring their path from original product, to ingredient, to ingredient within ingredient — and making it effectively impossible to track a contaminated or illness-causing food through its iterations down the chain.
The authors say:
… the trends shown in (the figure above) cannot be sustained if both free trade and the demand for biotracing are to be met. During a food poisoning outbreak the first and most important task is to identify the origin of the contamination. Delays in this task can have severe consequences for the health of the population and incur social, political and economical damages with international repercussions….
Note that our study does not predict an increase in the number of food poisoning cases but that, when it happens, there will be inevitable delays in identifying the sources due to the increasingly interwoven nature of the IFTN. That is, even if food contamination was less frequent, for example due to better local control of production, its dispersion/spread is becoming more efficient.
The paper is short and worth reading in its entirety, especially for its modeling of possible paths of hypothetical ingredients. It’s a chilling reminder, though, that if you buy any kind of processed food, you really have no way of knowing what’s in it. And even “buying local” might not protect you: The salad sprouts grown from those Egyptian seeds last year certainly seemed to be local to buyers, because they were raw, fresh and highly perishable. But the seeds they started as took a long trip to get to where they were sprouted, and as more than 3,000 sick people discovered, those seeds became contaminated in some untraceable spot along the way.
Cite: Ercsey-Ravasz M, Toroczkai Z, Lakner Z, Baranyi J (2012) Complexity of the International Agro-Food Trade Network and Its Impact on Food Safety. PLoS ONE 7(5): e37810. doi:10.1371/journal.pone.0037810