New Delhi, India
February 7, 2008
Source:
Ministry of the Environment
(India)
GM crops using recombinant DNA techniques have advantages over
the conventional crops. However as more and more GM crops are
being released for field-testing and commercialization, concerns
have been expressed regarding the risks arising from their use
due to potential risks to both human health and environment.
These apprehensions arise because GM technology crosses the
species barrier as compared to classical selection techniques,
thereby permitting the gene transfer among microorganisms,
plants and animals. There is no evidence that any unique hazards
exist in the development of GM crops, because of novel
combinations of genes. It is not true that all GM crops are
toxic or are likely to proliferate in the environment. However,
specific crops may be harmful by virtue of novel combinations of
traits they possess. This means that the concerns associated
with use of GMOs can differ greatly depending on the particular
gene-organism combination and therefore a case-by-case approach
is required for assessment of safety concerns.
Potential risks from the use of GM crops broadly fall under two
categories, risks to human and animal health as well as risks to
environment.
RISKS TO HUMAN AND ANIMAL HEALTH
Risks to human health are related mainly to toxicity,
allergenicity and antibiotic resistance of the new products.
The risk of toxicity may be directly related to the nature of
the product whose synthesis is controlled by the transgene or
the changes in the metabolism and the composition of the
organisms resulting from gene transfer. Most of the toxicity
risks can be assessed using scientific methods both
qualitatively and quantitatively.
The introduction of newer proteins in GM crops from the
organisms, which have not been consumed as foods, sometimes has
the risk of these proteins becoming allergens. However, it may
be noted that there is no evidence that GM crops pose more risks
than conventional products regarding the development of
allergies. Further, the new GM crops can be tested for allergens
prior to the commercial release. For example, when it was found
that the consumption of GM soybean with a methionine producing
gene from the Brazil nut could trigger an allergic response in
those sensitive subjects who were allergic to Brazil nut, the
product was not released for sale. 14 Issues Related to
Genetically Modified Crops.
The use of genes for antibiotic resistance as selectable markers
have also raised concerns regarding the transfer of such genes
to microorganisms and thereby aggravate the health problems due
to antibiotic resistance in the disease causing organisms.
Although, the probability of such transfer is extremely
rare,steps are being taken to reduce this risk by phasing out
their use.
There have been apprehensions about danger from eating the
foreign DNA in foods derived from GM crops i.e. the pieces of
DNA that did not originally occur in that food plant. DNA being
present in all living things such as plants, animals,
microorganisms is eaten by human beings with every meal. Most of
it is broken down into more basic molecules during the digestion
process whereas a small amount that is not broken down is either
absorbed into the blood stream or excreted. So far there is no
evidence that DNA from GM crops has any additional risk to human
health than DNA from conventional crops, animals or associated
microorganisms that are normally eaten. In cases where the GM
crops is to be used for animal feed, the similar concerns as
explained above are addressed.
RISKS TO ENVIRONMENT
Risks to environment due to release of GM crops include impact
of introduced traits on the other related species, the potential
build up of resistance in insect populations, effect on
biodiversity and unintended effects on non-targeted organisms.
Accidental cross breeding between GM crops and traditional
varieties through pollen transfer can contaminate the
traditional local varieties with transgenes. The consequences
associated with such gene transfer may impact intellectual
property, increase weediness if transferred to compatible weedy
relatives or lead to extinction endangered varieties of the same
genera. However, these risks can be anticipated easily and then
evaluated by experiments prior to any commercial release.
The gene transfer into a crop or the resultant products can
actually remain in environment leading to environmental problems
e.g. in case of Bt crops, it was suspected that insecticidal
proteins can persist in the environments but experiments have
proved that these are degraded in the soil. Further there are
concerns about possible interaction that may occur between other
organisms in the environment following the release of a GM crop.
Environmental concerns have also been raised about the
development of increased insect resistance, virus resistance and
weediness following the introduction of GM crops.
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