“Never confuse movement for action.”
Ernest Hemingway

As this multi-part series on FDA’s new rule approving commercial irradiation of fresh iceberg lettuce and fresh spinach comes to its conclusion, it is important to ask if and how this movement by the regulatory agency can be translated into action by industry and consumers to promote public health. I embarked on this literature review to help answer these questions, and to gain a better understanding of the pros (advantages) and cons (limitations) of implementing commercial irradiation of lettuce/spinach. Follow these links to read the entire series:

Part I. Definitions and Historical Perspective
Part II. Food Safety
Part III. Food Quality
Part IV. Consumers and Costs
Complete List of References
Updated Outbreak Table

As mentioned previously, food irradiation is not a “silver bullet” for food safety, but represents another tool in the toolbox of approaches to protect the food supply. Below is a summary of the findings from this review:

Pros (Advantages)

• Like pasteurization, food irradiation has widespread, worldwide endorsement by nearly every major medical and scientific organization

• Enhances food safety and can prevent illnesses, outbreaks, and recalls. The new FDA rule allows a maximum dosage of 4 kGy, which is effective at reducing or eliminating the major foodborne pathogens such as E. coli O157:H7 and Salmonella associated with recent lettuce/spinach outbreaks and recalls (see Table). Fewer outbreaks and recalls translates into:

o less direct and indirect costs to individuals and society due to medical bills and other expenses
o less litigation
o increased consumer confidence in leafy greens

• Unlike other sanitation methods for raw or minimally processed lettuce/spinach, irradiation will kill bacteria adhered to the outside or internalized within the edible plant tissues (for example, E. coli O157:H7 inside pores or stomata); regular washing by the consumer likely will not eliminate these bacteria

• Conducive to use by companies that supply institutions (restaurants, hospitals, nursing homes, long-term care facilities, schools/colleges, prisons and jails) with large quantities of bagged, minimally processed, pre-washed iceberg lettuce and spinach, which historically appear more vulnerable to serious foodborne disease outbreaks

• Enhances food quality by extending product shelf-life and promoting less food waste. Similar to foodborne pathogen reduction, the approved dosages for irradiation of lettuce and spinach significantly reduce the levels of spoilage bacteria and molds.

• Minor to no significant loss of important nutrients in lettuce and spinach, especially compared with nutrient loss following other common food preservation techniques (e.g., boiling and freezing) and losses during storage

• Limited to no detectable problems with sensory qualities - appearance, taste, texture, and aroma - especially at lower dosages (1 kGy)

• No chemical residues left on the product, and a consensus within the scientific community that the technology is safe and does not produce any “toxic substances” or “radioactivity” in the food or packaging. Indeed, the three specific sources (gamma rays, x-rays, e-beam) specifically approved by the FDA for food irradiation were approved because they do not make the food radioactive.

• Includes a Radura label that allows consumers to make a choice to buy or avoid irradiated product, depending on their assessment of the pros and cons.

Cons (Limitations)

• Lack of irradiation facilities near major lettuce/spinach production regions such as the Salinas Valley, and substantial costs associated with building new facilities; alternatively, the leafy green industry could ship product to existing facilities in other parts of the country, but this also adds costs that will likely be passed to the consumer

• Uncertainty about consumer acceptance of irradiation, especially for produce items. Some consumers fear of the word “irradiation,” which may be incorrectly associated with the words “atomic” or “nuclear.” Studies indicate that the primary reason consumers might not buy irradiated foods is due to insufficient information about the risks and benefits, thus underscoring the considerable need for education efforts

• Strong opposition to the use of irradiation in organic food production; FDA’s rule would not apply to organically produced lettuce and spinach since irradiation at the medium dose range is not allowed by USDA standards that define “certified organic” (Note: the 2006 E. coli O157:H7 outbreak was traced to bagged baby spinach grown organically)

• Not a replacement for good agricultural practices (GAPs) and good management practices (GMPs) on the farm and during harvest, transportation, and processing

• Does not prevent post-processing contamination during transport or by the retailer or consumer during food preparation and handling

• At the approved dose, irradiation may not effectively reduce viruses (e.g., norovirus, hepatitis A); spore forming bacteria such as Clostridium botulinum, and it does not eliminate toxins. However, these causes of foodborne illness and intoxication are rarely linked to fresh lettuce and spinach

• Some packaging material may not be appropriate (or FDA approved) for irradiation processing

From Movement to Action

Coincident with starting this series last fall, an outbreak of E. coli O157:H7 involving over 40 illnesses and numerous hospitalizations was linked to bagged, fresh-cut iceberg lettuce shipped to institutions in Michigan and Illinois. Earlier in 2008, Washington State reported an outbreak of E. coli O157:H7 among patrons that consumed Romaine lettuce at a Mexican restaurant. These outbreaks appear to have happened despite substantial efforts by the leafy green industry to implement stronger control measures to prevent contamination in the fields and processing facilities, especially in the Salinas Valley of California. Both of these outbreaks have resulted in lawsuits.

Stearns (2006) wisely notes in his chapter on the legal perspectives of food irradiation:

“Food irradiation has the capacity to substantially reduce not only the risk of lost sales that result from an outbreak or recall but also the lawsuits that inevitably follow.”

He goes on later in the chapter to say:

“Because it is clear that the size of the highly susceptible population [elderly, preschool age children, persons with AIDS, persons on chemotherapy, etc.] is certain to grow, the food industry has no choice but to take this increasing risk into account when making decisions about what, if any, additional steps to take to prevent a parallel increase in the incidence of foodborne illness attributable to its product.”

Given the gravity of the situation with continued illnesses and deaths linked to fresh produce, the “cons” (such as uncertainty about consumer acceptance and potential costs to implement irradiation), should not paralyze the effort to go from movement to action. The following are some suggestions for first steps to maximize the benefits of FDA’s new rule:

• All professionals in the food safety arena should work with experts in food irradiation companies to conduct a modern assessment of the estimated costs and benefits associated with implementation of the FDA rule for fresh iceberg lettuce and spinach. Specifically, these professionals should look closely at potential niche markets or at-risk groups that could benefit from the technology. For example, irradiation could have a significant impact (reduction of illnesses and outbreaks) if applied to products shipped to institutional settings (schools, hospitals, nursing homes, long-term care facilities, prisons) where populations are especially vulnerable to foodborne diseases.

• Government, industry, academia, health care providers, legal professionals, consumer groups, and other stakeholders need to provide and advertise an honest and balanced assessment of the pros and cons (advantages and disadvantages) of food irradiation including application of the FDA rule for fresh iceberg lettuce and spinach. This information should be readily available to the public via multiple sources including the Internet to allow the public to make an informed choice. Pszczola suggested that the medical and scientific communities “develop closer relationships with the media so emotionalism is not overemphasized compared with scientific facts.”

• The label for irradiated fresh iceberg lettuce and spinach (plus other approved foods) should include the Radura, and a general or incentive statement on the purpose of irradiation such as, “to kill harmful pathogens,” or “to reduce Salmonella and E. coli O157:H7.” It would also be worthwhile to consider phasing out the word “irradiation” and adopting a new term for this processing technology such as “cold pasteurization” or “electronic pasteurization (for e-beam processing),” which are still descriptive, but not associated with the words “nuclear” or “atomic.”

• FDA should expand the rule to include approval of other high-risk salad greens linked to foodborne disease outbreaks, especially Romaine lettuce. Public and private funding agencies should continue to provide support for research into the optimal conditions for use of ionizing radiation in different types of leafy greens and packaging materials that promote both food safety and food quality.