Allergic reactions and other possible health
risks
Threats to the environment
Essentially, we've been subjected to a massive
experiment on human health. What will the results of this experiment
be? Stay tuned.
Genetic engineering is a young, and in many ways poorly understood,
technology. Many scientists believe that genetically engineered
foods have been rushed much too quickly to market--to boost multinationals'
profit margins--before adequate testing has been completed to ensure
public health.
Early in 2001, the Royal Society of Canada-the
nation's foremost scientific body-said there was insufficient research
into the potential allergic effects and toxicity of genetically
engineered foods. GM foods could cause "serious risks to human
health," the society said.
According to the Washington Post, the
"dearth of studies is the legacy of a U.S. policy that considers
gene-altered plants and food to be fundamentally the same as conventional
ones, a policy some Americans are starting to question....
"And it is the legacy of broken promises
by the Food and Drug Administration and the Environmental Protection
Agency, both of which have said for the past five years that they
intend to write rules to minimize the chances that gene-altered
food will cause allergies or damage the environment."
Genetic engineering may involve the transfer of new and unidentified
proteins from one food into another, with the potential of setting
off allergic reactions. And allergies aren't simply a matter of
slight discomfort; they can potentially result in life-threatening
anaphylactic shock.
Without labeling, people with allergies won't
know if they are eating foods that contain genes from other foods
to which they are allergic.
In 1996, scientists were stunned to discover
that soybeans engineered to include protein-rich genes from the
Brazil nut also contained the allergenic properties of the Brazil
nut. Animal studies had not revealed the allergenic nature of the
mutated soybean. The manufacturer halted the release of the soybean
just in time.
But with dozens of new genetically engineered
crops under consideration, scientists believe much more extensive
testing is required to ensure that those who suffer from allergies
won't be affected by these foods.
Scientists also have discovered that Bacillus
thuringiensis (Bt), a bacterium that has been spliced into millions
of acres of corn, potatoes and cotton, may produce allergies in
people.
Science News reported in July 1999 that
a study of Ohio crop pickers and handlers shows that Bt "can
provoke immunological changes indicative of a developing allergy.
With long-term exposure, affected individuals may develop asthma
or other serious allergic reactions."
Scientists say genetic engineering may produce new toxins,
with potentially devastating results for humans. In at least one
case, disaster has already happened.
In 1989, a genetically engineered version of
tryptophan, a dietary supplement, produced toxic contaminants. Before
it was recalled by the Food and Drug Administration, the mutated
tryptophan wreaked havoc. Thirty-seven Americans died, 1,500 were
permanently disabled, and 5,000 became ill with a blood disorder,
eosinophila myalgia syndrome.
Genetic engineers use antibiotic "markers" in almost
every genetically modified organism to indicate that the organism
has been successfully engineered. Scientists believe these antibiotic
markers may contribute to the decreasing effectiveness of antibiotics
against diseases.
The journal Microbial Ecology in Health and Disease
reported in 1998 that commercial gene technology may be behind a
recent resurgence of drug- and antibiotic-resistant infectious diseases.
We'll let Dr. Mae-Wan Ho, author of the report (and author of Genetic
Engineering: Dream or Nightmare?), take over from here. She
says:
"At the heart of the issue is horizontal
gene transfer - the transfer of genes by vectors such as viruses
and other infectious agents - which is exploited by genetic engineers
to make transgenic organisms. While natural vectors respect species
barriers, the barrage of artificial vectors made by genetic engineers
are designed to cross species barriers, thus greatly enhancing the
potential for creating new viral and bacterial pathogens, and spreading
drug and antibiotic resistance. Totally unrelated pathogens are
showing up with identical virulence and antibiotic resistance genes.
"Recent statistics are frightening. Infectious
diseases were responsible for one-third of the 52 million deaths
from all causes in 1995. Multi-drug resistant tuberculosis is now
estimated to affect 10 million each year with 3 million deaths.
At least 50 new viruses attacking humans emerged between 1988 and
1996. Between 1986 and 1996, E. coli 0157:H7 infections increased
by 10-fold in England and Wales and 100-fold in Scotland. Vancomycin
resistance rose from 3 percent to 95 percent in San Francisco hospitals
in the four years between 1993 and 1997. And Staphyloccocus (toxic
shock syndrome) is now invulnerable to all known antibiotics.
"The first genetic engineers called for
a moratorium in the Asilomar Declaration of 1975, precisely because
they were afraid of inadvertently creating new viral and bacterial
pathogens. The worst case scenario they envisaged may be taking
shape. Commercial pressures led to regulatory guidelines based largely
on untested assumptions, all of which have been invalidated by recent
scientific findings. For example, biologically "crippled"
laboratory strains of bacteria can often survive in the environment
to exchange genes with other organisms. Genetic material (DNA) released
from dead and living cells, far from being rapidly broken down,
actually persists in the environment and transfers to other organisms.
Naked viral DNA may be more infectious, and have a wider host range
than the virus. Viral DNA resists digestion in the gut of mice,
enters the blood stream to infect white blood cells, spleen and
liver cells, and may even integrate into the mouse cell genome.
"'We may only be seeing the tip of the iceberg,'
the scientists state. 'There is an urgent need to tighten existing
regulations.' Instead, the EU is relaxing the guidelines on both
deliberate release and contained use of GMOs. 'That is an irresponsible
move in the light of existing scientific knowledge.'"
When biotech corporations boast that genetic engineering
can do wonders for the environment, we would do well to consider
the source. After all, some of these companies are the same ones
that have invented such deadly pesticides such as DDT and Agent
Orange. These pesticides, it was promised, would help the environment;
instead, they turned into environmental disasters.
Environmentalists have many concerns about GE
foods. Here are a few:
Cornell University researchers have found that GE corn may
be deadly to the Monarch butterfly. In laboratory tests in the spring
of 1999, the scientists found that nearly half of Monarch caterpillars
that ate milkweed leaves dusted with GE corn pollen died within
four days. The surviving Monarchs that ate the genetically mutated
corn pollen were much smaller and had smaller appetites than the
control Monarchs, which ate normal corn pollen or no pollen at all.
In 2000, Iowa State University scientists found
that plants growing in and near cornfields are being dusted with
enough GE pollen to kill monarch caterpillars that feed on them.
Already, GE corn is being grown on 20 million
acres of American farmland, right in the heart of Monarch's migratory
route between Mexico and Canada.
And scientists worry that there may be additional
surprising scientific discoveries down the road.
Many of the new GE crops, such as Roundup Ready soybeans,
are designed to allow farmers to spray heavier doses of pesticides
on their land. These pesticides inevitably will find their way into
our water and food supply, endangering humans and wildlife.
New Scientist magazine reports that many
farmers that have converted to GE production use as many pesticides
as their conventional counterparts, while some GE farmers now use
more pesticides.
And one of Britain's leading safety experts,
Malcolm Kane (former head of food safety at the supermarket chain
Sainsbury's), has revealed that the limits on pesticide residues
in soy had been increased 200-fold to help the GE industry. He warned
that higher pesticide residues could appear in a wide variety of
foods, ranging from breakfast cereals to biscuits.
When Scottish Parliament member Robin Harper learned that
Scottish scientists were experimenting with genetically modified
salmon that grow at four times the normal rate, he was horrified,
and called for a ban on all genetic engineering experiments.
"We should be extremely concerned about
genetically modified fish because of the danger that they could
escape into the wild," he said. "It's a similar, if not
even more dangerous threat, to that we are facing with GM plants.
If a GM fish escaped or was released accidentally in to the wild
it could never be recaptured. This fish could breed with wild populations
and devastate the existing natural balance with its modified behavior.
"There can be no doubt as to the huge threat
GM fish would be to fish stocks wherever they were released in the
World's oceans. This fish, if it escaped into the North Atlantic,
could do untold damage to the ecology both of the north Atlantic
and Scottish salmon rivers."
Like Harper, many scientists are concerned about
the widespread release of genetically modified organisms (GMOs)
into the environment. In the United States, millions of acres of
land have been planted with GE crops. Scientists fear that GMOs
will be spread, by bird, insect or wind, to non-GE crops--and to
the wilderness. And unlike other kinds of waste, genetic contamination
cannot be cleaned up, or contained.
In May, 2000, Professor Hans-Hinrich Katz, a leading German zoologist,
released research that shows that genes used to modify crops can
jump to other species and cause bacteria to mutate. Katz found that
the gene used to modify oilseed rape had transferred to bacteria
living in the guts of honey bees.
"These findings are very worrying and provide
the first real evidence of what many have feared," says prominent
genetic engineering critic and scientist Dr. Mae-Wan Ho.
"Everybody is keen to exploit GM technology,
but nobody is looking at the risk of horizontal gene transfer. We
are playing about with genetic structures that existed for millions
of years and the experiment is running out of control."
Some scientists fear that the extensive planting of genetically
engineered crops will lead to a new class of "superweeds"
that are resistant to pesticides. The largest class of genetic engineered
foods is pesticide-resistant crops, such as Roundup Ready soybeans.
The problem is that newly created transgenes may be spread unintentionally--by
bird, insect or wind--from target crops to related weed species.
The weeds then also pick up resistance to the pesticide.
Nature magazine reported in 1996, for
example, that herbicide-resistant GE oilseed rape, released in Europe,
has spread to several wild relatives.
In one especially macabre application of GE technology, scientists
seek to develop "terminator" tree farms. The trees would
be engineered not to reproduce, and they would be designed to secrete
toxic chemicals through their leaves that would kill leaf-eating
insects. The trees also would be engineered to include pesticide
resistance, meaning that ground flora could be wiped out easily.
Critics say the trees might grow faster than before, but they'd
be devoid of bees, butterflies, birds and squirrels that depend
on pollen, seed and nectar.
The terminator tree farms highlight a growing
concern among scientists: the threat genetically engineered crops
pose to biodiversity. Scientists estimate that by the year 2000,
the world will have lost 95 percent of the genetic diversity present
in agriculture 100 years earlier. GE crops are developed from the
same monoculture varieties that giant agribusinesses have planted
in the latter half of this century, and will only exacerbate the
problem.
Moreover, pesticide-resistant crops will allow
the application of increasing amounts of powerful pesticides. These
pesticides often kill more than the targeted weeds; they frequently
kill beneficial plants outside their intended range.
Scientists are concerned that genetically mutated crops may damage
the soil. Researchers for Nature magazine reported in December that
some types of GE crops may be leaking powerful toxins into the soil.
Many GE crops, such as corn and potatoes,
have been engineered to produce poisons or toxins to fight pests
that eat their leaves and stems. Researchers fear that beneficial
soil organisms also may be killed, and that some insects may become
resistant to the toxins.
Other researchers have revealed that lacewings
that ate corn borers reared on GE corn had also died, increasing
speculation that these crops are harming beneficial organisms.
British researchers in 2000 reported that the use of genetically
engineered crops modified to tolerate herbicides may severely cut
bird populations on farms. Professor Andrew Watkinson and colleagues
from the University of East Anglia in Norwich found that bird populations
could decline as much as 90 percent in some areas where herbicide-tolerant
crops have been sown.
Biotech firms assure us there's nothing to worry about. Genetically
engineered foods, they say, will save the environment.
But it's a story we've heard before. In the mid-1900s,
giant agribusinesses took the biological and chemical weapons from
two world wars and turned them into pesticides and herbicides. They
promised a wondrous new agricultural era of bigger yields and bug-free
produce. It was only decades afterwards that scientists began to
realize the scope of the environmental devastation wrought by the
explosive growth of the pesticide industry.
In the 1960s, scientist Rachel Carson's epic,
Silent Spring, awakened a generation to the dangers of dioxin
and other manmade chemicals in the environment. But it wasn't until
30 years later that scientists began to understand the extent of
the problem. Now we know that pesticides and other manmade chemicals
are tampering with sexual development and reproduction, in many
animal populations and humans as well.
The discovery that genetically engineered corn
might be deadly to Monarch butterflies came as a shock to biotech
advocates. If biotech companies continue with their massive experiment,
what will our scientists tell us 50 years from now?
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