A commentary published on July 6, 2016 in the peer-reviewed journal Environmental Health Perspectives argues that several crucial processes and inputs are currently not being sufficiently addressed when modeling human exposure to hazardous chemicals through food.
Carla Ng from the Department of Civil and Environmental Engineering, University of Pittsburgh, U.S., and Natalie von Goetz from the Institute for Chemical and Bioengineering, ETH Zurich, Switzerland, point out that the modern food system has become very complex, relying on global food transport across countries and continents, and exhibiting a high proportion of processed foods subject to additional chemical inputs during processing, packaging, and storage. Importantly, the specifics of the industrial handling of food may vary at different locations, and human-mediated global food transport erases the boundaries imparted by physical laws on the distribution of chemicals within and between the environmental media and world regions.
Two types of models currently used to understand chemical accumulation in food and subsequent human exposure include bioaccumulation models and human exposure models. The former models, tracing chemical accumulation from the environmental emissions across the food web, typically fail to account for the intermediate steps between harvest and consumption of foods (i.e. globally introduced food trade aspects such as processing, packaging, storage, and transport). The latter models estimate the exposure based on the measured levels of contaminants in foods of interest, along with consumption surveys and physiological data, but typically do not address the origin of the food. This situation results in a disconnect between chemical emission and human exposure, because chemical inputs due to the passage through the industrial food web are not being explicitly covered.
To account for the role of the global food system in the accumulation of chemicals in food, sophisticated models covering all stages of food production and consumption should be developed and integrated within one approach. In particular, models of chemical inputs during food trade-influenced processes, such as processing, packaging, storage, and transportation should be improved, and better means of tracing the origin of the food through the production and supply chain need to be made available.
Ng and von Goetz argue that a more comprehensive understanding of “how the complex chains of food transport, processing and packaging contribute to the overall contaminant profile in market-ready foods” would allow a better design of global food systems enabling a reduction in dietary exposure to chemicals.
Nate Seltenrich (January 1, 2017). “Exploring chemical transport through food: A proposal for a comprehensive approach to predict exposures.” Environmental Health Perspectives 125:A26.
Ng, C. and von Goetz, N. (2016). “The global food system as a transport pathway for hazardous chemicals: The missing link between emissions and exposure.” Environmental Health Perspectives (published July 6, 2016).