The state Department of Agriculture is working diligently, once again, toward the goal of building a fruit irradiation facility in Hawai`i. This time, the facility would be sited not on the Big Island — which was the intended site when such a facility was the subject of an environmental impact statement prepared in 1987. Rather, the focus of attention this time around seems to be O`ahu, more specifically, near Honolulu International Airport.
Recently, the state’s efforts in this arena came to light with the shipment in mid-April of more than 220 cases of untreated fresh papayas from Hawai`i to Chicago. There, the papayas were taken to an irradiation facility, operated by Isomedix, Inc., in nearby Morton Grove, Ill. Following irradiation, the papayas were distributed to about 20 retail outlets in the areas of Chicago and Toledo, Ohio. Among the stores selling the produce was Carrot Top, a produce store in the Chicago area that has made a name for itself as a retailer of irradiated foods. According to state Department of Agriculture officials, the experimental shipment was a huge success. In mid-June, the state sent a second shipment — this time of lychee — to Isomedix. Future shipments of other fruits are anticipated.
DOA Chairman James Nakatani, in a prepared statement, said the shipments would allow the state “to explore alternative ways to treat Hawai`i-grown papaya and potentially other local produce to allow for their safe shipment to the Mainland U.S. and most foreign countries. And, most important, this project will help the state identify new markets for our farmers.”
Long Lead Time
In 1989, it appeared that plans for an irradiation facility in Hawai`i were moribund. Up to $4 million in federal Department of Energy was available to help with financing the facility, and the state was prepared to provide an additional $1 million. But when the only qualified bid that the state received for construction of the facility was opened in January 1989, it was for $6 million. In July 1989, then-Governor John Waihe`e announced that the irradiator was “pretty much dead in the water.”
But the idea never dropped completely from the minds of some state workers. Chief among them is Lyle Wong, plant industry administrator for the DOA. As Environment Hawai`i reported in [url=/members_archives/archives_more.php?id=1245_0_30_0_C]January 1994[/url], Wong told the members of the Governor’s Agriculture Coordinating Committee on September 29, 1993, that irradiation was essential to expanding markets for tropical fruit. On September 22 and October 4, 1993, Wong met at the Office of State Planning with colleagues from the Office of State Planning, the Department of Business, Economic Development, and Tourism, the University of Hawai`i, and GACC, to discuss a strategy for “evaluating the need for a pilot irradiator for Hawai`i at this time,” Wong said in a report on the meetings. “The outcome of this review would be a recommendation for a specific kind of unit and its location, uses, and opportunities, etc., or a recommendation for no action, or something in between.” At that time, he indicated, a pilot irradiation plant could cost in the “neighborhood of $5-10 million.” In a report co-authored by Wong only a few months later, it appears that that review had occurred and the question resolved in favor of irradiation. In that report, titled, “Current Interest in and Prospect for Adopting Irradiation as a Quarantine Treatment Procedure in Hawai`i,” Wong wrote, with James H. Moy of the University of Hawai`i Food Science and Human Nutrition Department: “Consensus from recent meetings of state agency and industry representatives indicates a strong interest in pursuing radiation technology for the state of Hawai`i. A pilot irradiator is considered very useful for Hawai`i and USDA [U.S. Department of Agriculture] to jointly conduct research and development in using this technology as a quarantine treatment for selected commodities.” Wong and Moy went on to identify elements of a “tentative work plan”: “initiating planning of a pilot irradiator facility…; seeking funding both at the federal and state level for the irradiator…; constructing a pilot irradiator… and preparing plans for the management and utilization of the facility…”
In September 1994, Wong obtained from the USDA a list of conditions that would have to be met if the state wanted to ship untreated fruits to Chicago for irradiation there. In December, Wong hosted Jim and Paula Corrigan, owners of Carrot Top, on a trip to Hawai`i “to meet with growers … and to help lay out a business plan for a project.”
The first shipment was made in May. In June, Wong visited Chicago again to accompany a second shipment.
Thrips, Flies, and Weevils
For more than 40 years, the federal government has placed a quarantine on untreated shipments of most Hawai`i-grown fresh fruit. The islands have become home to four kinds of fruit flies, and fears that the flies will be carried in untreated fruit shipped to the continental United States are behind the quarantine.
The fumigant ethylene dibromide was used for years to treat Hawai`i fruits for export. In 1984, however, most uses of EDB were cancelled by the Environmental Protection Agency. Since then, papaya growers have developed several treatment protocols that satisfy USDA concerns. The treatment most commonly used is one or another variation of what is called the double-dip heat treatment process, which bathes the fruit twice in hot water or vapor heat. The high temperatures kill most flies and larvae, but at the cost of some loss in fruit quality. Papayas so treated have to be picked before they are fully ripe, and the fruit can become lumpy, especially in winter.
Commodities other than papayas are also prone to insect infestation. In their paper, Moy and Wong identify other possible beneficiaries of irradiation, including “cut flowers, orchids, foliage, some other nursery products, sweet basil, Asian basil, parsley, Chinese parsley, and other herbs. Most of these plants are infested with aphids, carmine spiders, mites, and thrips.” Mango and lychee are other crops that could be developed for export markets if the irradiator facility were in use, they say.
As a means of broadening support for the facility, Moy and Wong suggest it might be used not only by agricultural producers, but also could be used to “help improve public health by decontaminating poultry products,” noting that “Hawai`i has the highest incidents of Salmonellosis in the U.S.” — although they give no citation to support this claim (and the state epidemiologist, Dr. Richard Vogt, says it absolutely is not true). Additionally, they say that their facility could “provide an irradiation service to those organizations that have infested materials (e.g., library and museum),” and “provide an opportunity to develop a new industry (e.g., wood plastics), which might be useful because of the prevalence of ground and wood termites in Hawai`i.”
URPs
In his memorandum on the September and October 1993 meetings, Wong indicates slight attention was paid at these gatherings to concerns over the health and safety of the irradiation process. Rather, Wong writes: “We generally agreed … substantial literature is available on irradiation and the conventional scientific opinion is that the process is safe.”
In fact, scientific articles on this subject that have been published in peer-reviewed journals do not support claims of irradiation’s safety. The process of irradiation is known to alter the chemical make-up of food, resulting in the creation of what are called unique radiolytic products — URPs, for short. And while irradiation can kill some of the bacteria, molds, and insect larvae that shorten the shelf life of fresh produce (and which may cause superficial blemishes, making the produce unappealing to consumers), no one knows what the impacts on human health may be from ingesting these radiolytic products — which include such substances as benzene, peroxide, and carbonyls.
Apart from the radiolytic products, irradiation can diminish the nutritional value of food by destroying vitamins — particularly vitamins C and A, beta carotene, and the complex of B vitamins.
Worker Safety
Over and above the safety of food that has been irradiated, there are outstanding questions about the safety of the technology used. In general, irradiators use either cobalt-60 or cesium-137 as the source of the radiation used to “zap” foods. And those sources must be extremely potent to administer the high levels of radiation required to meet USDA standards. In Hawai`i, any irradiator would probably use cobalt-60 as the source; use of cesium-137 was banned by the Legislature. A third option is high-energy electron beams, similar to X-rays, but the technology for this is not well-established.
How high are those doses? Well, the doses absorbed by a Hawai`i-grown papaya must be at a minimum 15,000 rads (15 kilorads, or 150 Grays) to meet USDA requirements for export. That is about 15 million times the radiation dose received by a person undergoing a medical X-ray. The 1987 environmental impact statement for an irradiator in Hilo anticipated dosages as high as 1000 Grays. (To ensure that all fruit receives the minimum dosage, some fruit would be exposed to far higher levels of radiation than the minimum.)1
The University of California at Berkeley School of Public Health has taken the position that the “most serious human exposure to the products of irradiation comes not from the food itself, but from the irradiation plants.” In the school’s “Wellness Letter” of May 1992, the editors write, “About 40 plants now operate in the U.S. primarily to sterilize medical equipment. But if, for example, all the nation’s poultry were to be irradiated, hundreds of new plants would have to be built, posing many dangers. Not the least of these might be accidents and leakage — and enormous cleanup costs in case any radiation spills took place.”
In fact, the safety record of irradiation facilities is not unblemished. In the past, accidents have resulted in workers being exposed to dangerous levels of radiation. At least one worker in Norway died as a result of radiation burns received at a cobalt-60 irradiation facility, when the source material did not retract into a shielded position. In just the last year, the Nuclear Regulatory Commission issued an Information Notice to irradiation facilities in the United States, alerting them to a possible equipment defect that could lead to the radiation sources failing to return to a shielded position.
Hawai`i has already had one accident with a demonstration irradiator facility in pace at Fort Armstrong on O`ahu from 1967 to 1980. In early 1967, a shipment of cobalt-60 “pencils” corroded through their stainless-steel casing, releasing radioactive materials into the shipping cask. As described in the 1987 EIS for the Hilo irradiation facility, “about 9 curies of cobalt-60 escaped from the shipping casks into the storage pool water and was detected. When the contaminated cask and its load of pencils were lifted back out of the pool and through the roof of the building, a small amount of cobalt dribbled onto the roof. Rain later washed it off the roof and onto a section of lawn. The contaminated soil was immediately placed into 55-gallon drums and shipped to the mainland for disposal. Thirteen years later, the irradiator was decommissioned and a small amount of residual radioactivity posing no significant radiation hazard was found.”
Dubious Benefits
Proponents of irradiation say it would reduce the need for pesticides. Environment Hawai`i could find no study comparing the pesticide applications onto non-irradiated produce to those of irradiated produce. Since irradiation, at best, can only preserve produce in its harvested state, growers will still need to ensure their produce matures to the point it is marketable — and, to the extent that this involves application of pesticides, there would seem to be no association between irradiation and declining pesticide use. In fact, in some cases (including papayas), produce intended for irradiation is harvested when it is riper than untreated produce. In such cases, irradiation, by prolonging the growing season, may actually increase the use of pesticides.
Nor will irradiation eliminate the need for refrigeration to preserve treated fruits. Although irradiation, at sufficiently high doses, kills the organisms on fruit at the time of irradiation, it cannot prevent later reinfestation by bacteria and insects. If fruit needed refrigeration for extended shelf life in its untreated form, it probably needs refrigeration after irradiation as well. As reported by scientists who investigated the shelf-life of 20 different commodities, “irradiation holds little promise for perishable commodities… Occasionally, irradiation is suggested as a promising substitute for refrigeration. This hope should be dispelled with respect to controlling rot or senescence in fruits and vegetables.”2
Another claim of proponents is that irradiated fruit survives the rigors of shipment to market better than non-treated fruit. The same scientists who investigated the shelf-life of treated and untreated commodities found that, “without exception in all commodities studied, irradiation increased susceptibility to transit injury… In actual and simulated transit, mechanical injury of all these fruits was intolerably high in irradiated specimens.”
1. The standard unit of measuring radiation dosage per kilogram of material processed is the Gray, abbreviated as GY. One Gray equals 100 rads. The 1987 EIS states that the “total radiation dosage given the fruit would not exceed 1000 GY,” a dose equivalent, in other words, to one million rads. A kiloGray is equal to the amount of heat energy needed to raise the temperature of a liter of water by .24 degrees Celsius.
2. E.C. Maxie, N.F. Sommer, and F.G. Mitchell, “Infeasibility of Irradiation Fresh Fruits and Vegetables,” Horticultural Science, 1971 (Vol. 6), page 202.
— Patricia Tummons
Volume 6, Number 1 July 1995
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