food irradiation - again

FDA: Irradiating spinach, lettuce OK to kill germs
By LAURAN NEERGAARD, AP Medical WriterThu Aug 21

Consumers worried about salad safety may soon be able to buy fresh spinach and iceberg lettuce zapped with just enough radiation to kill E. coli  and a few other germs.
The Food and Drug Administration on Friday will issue a regulation allowing spinach and lettuce sellers to take that extra step, a long-awaited move amid increasing outbreaks from raw produce.
It doesn't excuse dirty produce, warned Dr. Laura Tarantino, FDA's chief of food additive safety.  Farms and processors still must follow standard rules to keep the greens as clean as possible - and consumers, too, should wash the leaves before eating.
"What this does is give producers and processors one more tool in the toolbox to make these commodities safer and protect public health," Tarantino said.
Irradiated meat has been around for years, particularly ground beef that is a favorite hiding spot for E. coli.  Spices also can be irradiated.
But the Grocery Manufacturers Association had petitioned the FDA to allow irradiation of fresh produce, too, starting with leafy greens that have sparked numerous recent outbreaks, including E. coli  in spinach that in 2006 killed three people and sickened nearly 200.
The industry group wouldn't name salad suppliers ready to start irradiating.  But it expects niche marketing to trickle out first - bags of spinach and lettuce targeted to high-risk populations such as people with weak immune systems "who right now may be afraid to eat uncooked produce," said GMA's chief science officer Robert Brackett.
"It's one big step forward in improving the safety of fresh produce," he added.
California-based produce giant Dole Food Company confirmed it is considering irradiated lettuce. "We are currently doing extensive testing with irradiation and it looks to be very promising," said spokesman William Goldfield.
A leading food safety expert said irradiation indeed can kill certain bacteria safely - but it doesn't kill viruses that also increasingly contaminate produce, and it isn't as effective as tightening steps to prevent contamination starting at the farm.
"It won't control all hazards on these products," cautioned Caroline Smith DeWaal of the Center for Science in the Public Interest.
She questioned why the FDA hasn't addressed her agency's 2006 call to require growers to document such things as how they use manure and ensure the safety of irrigation water. Irrigation is one suspect in this summer's nationwide salmonella outbreak attributed first to tomatoes and then to Mexican hot peppers.
"We are not opposed to the use of irradiation," DeWaal said.  But, "it's expensive and it doesn't really address the problem at the source."
Won't zapping leafy greens with X-rays or other means of radiation leave them limp? Not with today's modern techniques and the right dose, the FDA decided.
The FDA determined that irradiation can kill E. coli, salmonella and listeria, as well as lengthen shelf life, without compromising the safety, texture or nutrient value of raw spinach lettuce - the first greens studied.
E. coli actually is fairly sensitive to radiation, while salmonella and listeria require more energy. While irradiation doesn't sterilize, the FDA ruled that food companies could use a dose proven to dramatically reduce levels of those germs, a dose somewhat lower than meat requires.

But consumers shouldn't consider irradiation a panacea, either.  While E. coli  and salmonella tend to affect more people and make bigger headlines, consumer advocate DeWaal has found that norovirus contamination is a leading cause of produce outbreaks.
The irradiation rule goes into effect Friday.  The FDA still is considering industry's petition to allow irradiation of additional produce.  The grocery manufacturers group will push for other greens, such as Romaine lettuce, to be next, so that producers could irradiate bags of salad mixes.

While irradiated foods initially caused some consumer concern, FDA's Tarantino stressed that the food itself harbors no radiation.
"There is no residue, there's nothing left and certainly no radioactivity left," she said.
RM comments:
                Food can be irradiated with gamma rays, or with electrons from an accelerator.  The latter method, if the electrons are too energetic, can actually create radioactivity in the food.
        It was shown decades ago that food irradiation (FI) with gamma rays or hard X-rays produces in the food a range of peroxides, epoxides, and free radicals which do not occur naturally in food and should be deemed, prima facie, poisonous.  Although all microbes are killed in the food, the chemical damage within some classes of food makes it obviously unwholesome.
        Unfortunately, the nuclear industry has for a half-century assiduously & dishonestly promoted FI as a means of getting some ostensible good from some of its intractable byproducts, notably caesium-137 which is a main fission product.  Also cobalt-60 has been used as a gamma source for FI, produced in nuclear reactors (not all as inevitable fission product  -  ordinary cobalt is exposed to the high neutron flux in a reactor to transmute it into cobalt-60.)
        A decade ago some foreigners tried to slap a million curies of cobalt-60 into our then Prime Minister's electorate for FI (initially disguised under PR cover of sterilising medical equipment, beehive parts contaminated by Bacillus larvae, etc  -  but there was little doubt they intended bulk FI).   This caper was stopped by a broadly-based national movement in the course of which we learned much about FI.

        The claimed benefits of FI would obviously appeal strongly to the US Army, and sure enough the US Army was the main funder of the early research.  The UC Davis prof Sommer in charge of that big research programme concluded that FI was "infeasible".  Find out how much FI the US Army uses today! 
        This is relevant to GM-food.  The principle is the same: a novel process to modify food should not be permitted until proper testing has shown the modified food to be OK.  Pusztai & Ewen, and Showa Denko before them, have produced evidence that GMF can be very much *not* OK; now this German lab has shown that FI is actually harmful; but in neither case is there any surprise.