From New York Times:
September 21, 2006
The New York Times
Leafy Green Sewage
By NINA PLANCK
FARMERS and food safety officials still have much to figure out about
the recent spate of E. coli infections linked to raw spinach. So far,
no particular stomachache has been traced to any particular farm
irrigated by any particular river.
There is also no evidence so far that Natural Selection Foods, the
huge shipper implicated in the outbreak that packages salad greens
under more than two dozen brands, including Earthbound Farm, O Organic
and the Farmer's Market, failed to use proper handling methods.
Indeed, this epidemic, which has infected more than 100 people and
resulted in at least one death, probably has little do with the folks
who grow and package your greens. The detective trail ultimately leads
back to a seemingly unrelated food industry ? beef and dairy cattle.
First, some basic facts about this usually harmless bacterium: E. coli
is abundant in the digestive systems of healthy cattle and humans, and
if your potato salad happened to be carrying the average E. coli, the
acid in your gut is usually enough to kill it.
But the villain in this outbreak, E. coli O157:H7, is far scarier, at
least for humans. Your stomach juices are not strong enough to kill
this acid-loving bacterium, which is why it's more likely than other
members of the E. coli family to produce abdominal cramps, diarrhea,
fever and, in rare cases, fatal kidney failure.
Where does this particularly virulent strain come from? It's not found
in the intestinal tracts of cattle raised on their natural diet of
grass, hay and other fibrous forage. No, O157 thrives in a new ? that
is, recent in the history of animal diets ? biological niche: the
unnaturally acidic stomachs of beef and dairy cattle fed on grain, the
typical ration on most industrial farms. It's the infected manure from
these grain-fed cattle that contaminates the groundwater and spreads
the bacteria to produce, like spinach, growing on neighboring farms.
In 2003, The Journal of Dairy Science noted that up to 80 percent of
dairy cattle carry O157. (Fortunately, food safety measures prevent
contaminated fecal matter from getting into most of our food most of
the time.) Happily, the journal also provided a remedy based on a
simple experiment. When cows were switched from a grain diet to hay
for only five days, O157 declined 1,000-fold.
This is good news. In a week, we could choke O157 from its favorite
home ? even if beef cattle were switched to a forage diet just seven
days before slaughter, it would greatly reduce cross-contamination by
manure of, say, hamburger in meat-packing plants. Such a measure might
have prevented the E. coli outbreak that plagued the Jack in the Box
fast food chain in 1993.
Unfortunately, it would take more than a week to reduce the
contamination of ground water, flood water and rivers ? all irrigation
sources on spinach farms ? by the E-coli-infected manure from cattle
The United States Department of Agriculture does recognize the threat
from these huge lagoons of waste, and so pays 75 percent of the cost
for a confinement cattle farmer to make manure pits watertight, either
by lining them with concrete or building them above ground. But
taxpayers are financing a policy that only treats the symptom, not the
disease, and at great expense. There remains only one long-term
remedy, and it's still the simplest one: stop feeding grain to cattle.
California's spinach industry is now the financial victim of an
outbreak it probably did not cause, and meanwhile, thousands of acres
of other produce are still downstream from these lakes of E.
coli-ridden cattle manure. So give the spinach growers a break, and
direct your attention to the people in our agricultural community who
just might be able to solve this deadly problem: the beef and dairy
Nina Planck is the author of "Real Food: What to Eat and Why.''