Consequences of GM Crop Contamination ‘Are Set to Worsen’

Tue Feb 19, 2008 4:58 pm (PST)

Consequences of GM Crop Contamination `Are Set to Worsen’
Published on Monday, February 18, 2008.

Source: London Guardian

The consequences of contamination between GM crops and non-GM
varieties will be much more serious with the next generation of GM
crops, an influential group of US scientists has warned.0218 04

Mixing between GM and non-GM varieties has already caused serious
economic losses for producers in lost sales and exports. But the
consequences of mixing will be much more serious with new crops that
are altered to produce pharmaceuticals and industrial chemicals, the
scientists argue. The crops could harm human health and be toxic to
wild animals.

“What would be the impact societally, economically if for example,
cornflakes were contaminated by some sort of drug or chemical? I think
it would be a vast impact economically,” said Karen Perry Stillerman,
senior food and environment programme analyst with the Union of
Concerned Scientists.

“I think it’s really hard to say [what impact contamination would
have] because there is a variety of different drugs and chemicals that
might be manufactured in plants this way,” she added. “Our perception
is that some of them might be toxic, but all of them would certainly
cause tremendous economic upheaval.”

The group presented its findings at the American Association for the
Advancement of Science conference in Boston.

Huge research effort

Up to now, commercial GM varieties have been restricted mainly to
modifications for herbicide tolerance or resistance to pests. But a
huge research effort is going into a new generation of crops that are
genetically modified to produce drugs, hormones, vaccines and
industrial chemicals such as the precursors of plastics.

Although public opinion in Britain and the rest of Europe remains
firmly against GM crops in general, it is more favourable to crops
with medical benefits. But the Union of Concerned Scientists said that
these are precisely the crops that pose the greatest risks if they
exchange genes with wild relatives or conventional versions of the
same crop.

So-called “pharma crops” can offer advantages over current methods of
drug manufacture. Vaccines produced this way could be grown cheaply in
developing countries and simply given to patients in the food. That
would remove the need for sterile needles and refrigerators to keep
vaccine doses cold – a major obstacle for delivering therapies in poor
countries.

Prof Paul Gepts, a plant geneticist at the University of California,
Davis, said past experience suggests that “contamination” events
cannot be avoided. “Gene flow is really a regular occurrence among
plants. So if you put a gene out there it’s going to escape. It’s
going to go to other varieties of the same crop or to its wild
relatives,” he said. “It’s clear that zero contamination is impossible
at present.”

Major economic losses

There have been a handful of examples in the US and elsewhere of genes
from GM varieties not cleared for human consumption getting into
nearby food crops and hence the human food chain. This has led to
major economic losses for producers in lost sales, exports and
clean-up costs, but there have been no proven cases of damage to human
health.

“With the products we are talking about, there’s the potential for
that to be much more serious than what we have seen so far,” said Prof
Robert Wisner at Iowa State University.

According to Gepts, most of the ideas for keeping crops apart are
inadequate, because pollen and seed are carried on the wind, by
animals and birds and on farm machinery. He said the only way to be
sure that food crops would not be contaminated by drug genes or genes
for industrial chemicals would be to use non-food crops such as tobacco.

Alternatively, GM food plants could be grown in greenhouses or
underground to prevent pollen escaping, he said.

Call for ban

The Union of Concerned Scientists is calling on the US Department of
Agriculture to ban the growth of GM pharma crops outdoors unless they
are species that are not eaten by people or livestock.

The USDA is currently putting together new guidelines on GM that are
expected to be completed by the end of the year. Currently, no GM
crops that produce industrial chemicals or pharma crops are grown
commercially, although there are some field trials under way in the US.

Similar issues will apply in the UK and Europe if pharma crops are
approved. So far, though, only a handful of GM crop varieties are
grown in Europe.