(Part 2 of 6)
Q4: How are the potential
risks to human health determined?
The safety assessment of GM
foods generally investigates: (a) direct health effects (toxicity),
(b) tendencies to provoke allergic reaction (allergenicity);
(c) specific components thought to have nutritional or toxic
properties; (d) the stability of the inserted gene; (e) nutritional
effects associated with genetic modification; and (f) any
unintended effects which could result from the gene insertion.
Q5: What are the main issues
of concern for human health?
While theoretical discussions
have covered a broad range of aspects, the three main issues
debated are tendencies to provoke allergic reaction (allergenicity),
gene transfer and outcrossing.
Allergenicity. As a matter
of principle, the transfer of genes from commonly allergenic
foods is discouraged unless it can be demonstrated that the
protein product of the transferred gene is not allergenic.
While traditionally developed foods are nor generally tested
for allergenicity, protocols for tests for GM foods have been
evaluated by the Food and Agriculture Organization of the
United Nations (FAO) and WHO. No allergic effects have been
found relative to GM foods currently on the market.
Gene transfer. Gene transfer
from GM food to cells of the body or to bacteria in the gastrointestinal
tract would cause concern if the transferred genetic material
adversely affects human health. This would be particularly
relevant if antibiotic resistance genes, used in creating
GMOs, were to be transferred. Although the probability of
transfer is low, the use of technology without antibiotic
resistance genes has been encouraged by a recent FAO/WHO expert
panel.
Outcrossing. The movement of
genes from GM plants into conventional crops or related species
in the wild (referred to as "outcrossing"), as well
as the mixing of crops derived from conventional seeds with
those grown using GM crops, may have an indirect effect on
food safety and food security. This is risk is real, as was
shown when traces of a maize type which was only approved
for feed use appeared in maize products for human consumption
in the United States of America. Several countries have adopted
strategies to reduce mixing, including a clear separation
of the fields within which GM crops and conventional crops
are grown.
Feasibility and methods for
post-marketing monitoring of GM food products, for the continued
surveillance of the safety of GM food products, are under
discussion.
Q6: How is a risk assessment
for the environment performed?
Environmental risk assessments
cover both the GMO concerned and the potential receiving environment.
The assessment process includes evaluation of the characteristics
of the GMO and its effect and stability in the environment,
combined with ecological characteristics of the environment
in which the introduction will take place. The assessment
also includes unintended effects which could result from the
insertion of the new gene.
Q7: What are the issues of
concern for the environment?
Issues of concern include:
the capability of the GMO to escape and potentially introduce
the engineered genes into wild populations; the persistence
of the gene after the GMO has been harvested; the susceptibility
of nontarget organisms (e.g. insects which are not pests)
to the gene product; the stability of the gene; the reduction
in the spectrum of other plants including loss of biodiversity;
and increased used of chemicals in agriculture. The environmental
aspects of GM crops vary considerably according to local conditions.
Current investigations focus
on; the potentially detrimental effects on beneficial insects
or a faster introduction of resistant insects; the potential
generation of new plant pathogens; the potential detrimental
consequences for plant biodiversity and wildlife, and a decreased
use of the important practice of crop rotation in certain
local situations; and the movement of herbicide resistance
genes to other plants.
Q8: Are GM foods safe?
Different GM organisms include
different genes inserted in different ways. This means that
individual GM food and safety should be assessed on a case-by-case
basis and that is no possible to make general statements on
the safety of all GM foods.
GM foods currently available
on the international market have passed risk assessments and
are not likely to present risks for human health. In addition,
no effects on human health have been shown as a result of
the consumption of such foods by the genral population in
the countries where they have been approved. Continues use
of risk assessments based on the Codex principles and, where
appropriate, including post market monitoring, should form
the basis of evaluating the safety of GM foods.
Q9: How are GM foods regulated
nationally?
The way governments have regulated GM foods varies. In some
countries GM foods are not yet regulated. Countries which
have legislation in place focus primarily on assessment of
risks for consumer health. Countries which have provisions
for GM foods usually also regulate GMOs in general, taking
into account health and environmental risks, as well as control
and trade-related issues (such as potential testing and labelling
regimes). In view of the dynamics of the debate on GM foods,
legislation is likely to continue to evolve.
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