Jordan Argyle and Matthew Memmott, Department of Chemical Engineering
Introduction
At least 1 in 10 people across the globe do not have access to clean water.1 The World Health Organization considers food and drink contamination to be “the most widespread health problem in the contemporary world.”2 An estimated 600 million people fall ill from eating contaminated food or drinking contaminated water every year, of which nearly half a million die. Most of those illnesses are caused by pathogens rather than chemical contamination.3
Studies show that practical methods of sanitation, such as iodine capsules or boiling, are not
consistently used, even when the consumer is fully educated on the necessity of such treatment.4 A more proactive method that requires less involvement by the consumer has been shown to be effective,such as the large-scale water treatment systems in the United States. However, such methods for food and water sanitation generally have high capital and operating costs, and require a consistent energy supply, which is not usually available where it is most needed.5
Common treatment involve extreme temperatures, the use of chemicals, or subject the food to other
conditions. These treatments cause considerable damage to the molecular structure of the food,6 reducing its nutrition, shelf life, and flavor.7
The purpose of this project was to develop a low-cost, effective, long-lasting method for sanitizing
food and/or water that will not require frequent chemical or energy replenishment. The author proposes
a basic concept for using unstable isotopes to produce high energy photons capable of disabling or
killing pathogens in food or water.8 This treatment method results in less molecular deterioration, improving nutritional content of treated food and often leaving the flavor indistinguishable from fresh food, as well as providing other benefits, including delayed ripening, reducing food shipping costs,9 and even reducing allergenicity.10 Because the method is versatile, it can be easily applied to other needs, such as sterilizing medical equipment, with little modification.
Methodology
The first step was to delve into the Chart of Nuclides11 to find isotopes with a potentially useful quantity of photons produced per second, known as fluence, and a useful energy, which was taken to correlate with the numerous studies on x-ray and ultraviolet sanitation. To satisfy the fluence
requirement, a half life of 300 years was decided as the maximum, and 100 days as the minimum. This
resulted in a short-list of 99 isotopes, which are nicely organized on public knowledge sites.12
Gamma energy is well characterized for a great many nuclides, including the 99 we selected, but as we
followed the decay chains, it was quickly realized that gathering and organizing the full chain energy
data for a given isotope was non-trivial. Options for collecting that information included using exportcontrolled code which returned the data in a computer-usable format and required custom code to
process further, or manual entry, which is what we opted for, though neither option really provided
what we needed. One member of the team focused on this aspect of the project.
Considerable research was undertaken by other members of the team, who cataloged and annotated
potentially useful sources in Mendeley.13 This research included papers on effects of the photons on molecular structure, previous experiments with x-ray generators, and studies on the safety of such treatment. Parallel to the primary research, a device was conceived which would sanitize food in a batch-wise process, as well as continuously sanitizing water. The device was modeled in the CAD
package CATIA, and multiple options for shielding were considered.
Finally, as the project crosses multiple fields of study, the author contacted and visited professors in multiple departments to discuss collaboration possibilities, and worked with the professor mentor to
develop a research project that would satisfy academic needs, as well as advance the project.
Results
The work over the period of the Orca grant (January-August 2016) ultimately led to two provisional
patents,14 and the development of an inter-departmental research project involving at least Nutrition and Food Science, Molecular Biology, Chemical Engineering, and Mechanical Engineering, with the likely inclusion of other Life Science departments and Information Technology. The author is currently working to establish a company to represent a public face for the work, and to market the life-saving technology.
Discussion
The raw nuclear data needed for the project is not currently available for quick analysis and download.
Following the decay chains required that we gather data for roughly 300 additional isotopes, and we
found that our manual method was not scalable to the task, and no useful codes for this work were
found. Additionally, to accurately model the interaction of the photons with food, water, medical
equipment, pathogens, or anything else of interest requires significantly more data—on the order of
tens of gigabytes.
This delayed the development of a prototype, and changed our focus to be on combing literature for
useful information on the safety, efficacy, and use of energetic photons in sanitation and preservation
applications. While we did create plans for a testing device on the scale of a typical microwave oven—
which is what was eventually patented—we could not fully qualify our computations due to inability to
access as much data as would be necessary. Significant work has gone into developing a continuing
research program, which includes some of the following:
Conclusion
The project made significant headway in laying the groundwork for the research project to continue,
including work on data, designing and patenting a prototype, sifting through literature, and making
connections to forward the work over the next few years. While organizing the data for our 99 chosen
starting isotopes, we learned to read and understand public databases that contain this information, and pinpointed future data needs. The prototype design is flexible and can easily be adapted to
accommodate anticipated changes based on full analysis when the data is prepared. Over 100 books
and articles on the safety, efficacy, economics, value, and results of treating food with high-energy
photons were categorized and annotated, and professors from the critical departments were contacted
and have expressed interest in the research.
1 (JMP), W. H. O. and U. J. M. P. Progress on Drinking Water and Sanitation, 2015 Update and MDG
Assessment. (2015). AND citation 7.
2 The role of food safety in health and development. WHO Tech. Rep. Ser. 659, (1984).
3 Who Food Safety Fact Sheet, 2015, http://www.who.int/mediacentre/factsheets/fs399/en
4 Banerjee, A. & Duflo, E. Low-hanging fruit for better (global) health? Poor Econ. A Radic. Rethink. W. to Fight Glob. Poverty 41–70 (2011).
5 WHO estimates of the global burden of foodborne diseases, [A report by the] Foodborne diseases burden epidemiology reference group, 2007-2015, pg 75 (map of where people die, almost all of them places with unreliable power) cf with http://www.iea.org/statistics/statisticssearch, which shows that many nations with high death rates have low power generation/capita.
6 Davidek, Jiři. Chemical Changes during Food Processing. Amsterdam U.a.: Elsevier, 1990. Print.
7 The role of food safety in health and development. WHO Tech. Rep. Ser. 659, (1984).
8 Edward S Josephson, Preservation Of Food By Ionizing Radiation, vol III
9 Molins, R. ., Motarjemi, Y. & Käferstein, F. . Irradiation: a critical control point in ensuring the microbiological safety of raw foods. Food Control 12, 347–356 (2001).
10 Vaz, A. F. M. et al. Gamma irradiation as an alternative treatment to abolish allergenicity of lectins in food.
Food Chem. 124, 1289–1295 (2011). AND
Vaz, A. F. M. et al. High doses of gamma radiation suppress allergic effect induced by food lectin. Radiat.Phys. Chem. 85, 218–226 (2013). AND
Vaz, A. F. M. et al. Molecular fragmentation of wheat-germ agglutinin induced by food irradiation reduces its allergenicity in sensitised mice. Food Chem. 132, 1033–1039 (2012).
11 International Atomic Energy Agency, Live Chart of Nuclides
https://www-nds.iaea.org/relnsd/vcharthtml/VChartHTML.html
12 Wikipedia List of (Selected) Nuclides, https://en.wikipedia.org/wiki/List_of_nuclides . To find the 99 that we selected,go to the section titled “Radionuclides with a half life of 1 day to 50 million years,” and sort by half-life. There is a halflife (years/days) column that is easier to read. From there, just scroll to where the half lives are between 100 days and 300 years.
13 A program for organizing, annotating, and sharing research documents, https://www.mendeley.com
14 U.S. Provisional Patent Application No 62/343,345, filed May 31, 2016 as “Personal Food and Water Sanitation Device Using Energetic Photons from Isotope Sources”
U. S. Provision Patent Application No 62/343,392, filed May 31, 2016 as “Containment Dome for Safe Storage, Shipping, and Use of Radio-isotopes”