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Issue
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Scientific Convergence
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Scientific Divergence
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Gaps in Knowledge
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Safety of currently available GM foods for human consumption
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Currently available GM foods are considered safe to eat.
No evidence of any adverse effects from consumption
to date.
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Post-market surveillance is difficult due to confounding effects of
diversity of diets and genetic variability in populations.
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Long-term effects unknown, both for GM and for most other foods.
How to conduct post-market surveillance?
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Future products
(e.g. foods with modified nutritional content)
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Need to be assessed on case-by-case basis to ensure pre-market safety,
before new foods are brought to market.
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Extent of safety analysis should be proportionate to risk.
Product
and/or process may be assessed.
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Unintended effects possible, either through conventional plant
breeding or gene technology.
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Methods of food safety assessment
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Case by case analysis required, using scientifically robust
techniques.
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Current safety assessment methods, largely based on comparison of a
limited number of compounds, may not be adequate to assess more complex
products, which are not substantially equivalent to present foods.
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Whole food analysis is possible,
but requires further R&D to validate new techniques and
interpretation of data.
Need to know how much change in food content is nutritionally
significant.
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Health benefits
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Many GM crops are now grown with less pesticide, thereby reducing
exposure to chemical pesticides.
In the future, crops may be used to produce new
pharmaceutical/medicinal compounds (e.g. vaccines).
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Future GM crops may have improved nutritional content (e.g.
vitamin A rice).
Need to ensure quality control of new products and keep pharmaceutical
products out of the food chain. This may be difficult.
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Availability
of nutritionally significant levels of vitamins and
minerals in GM foods needs to be demonstrated.
Need to demonstrate new crop management practices for novel products,
to ensure they can be kept out of the food chain and adequately
regulated.
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Issue
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Scientific
Convergence
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Scientific
Divergence
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Gaps
in Knowledge
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Direct effects
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Agriculture affects the environment.
Environmental effects of LMOs may be negative or positive. Requires
case-by-case assessment.
Direct effects of GM crops may include gene flow from GM crops to
local land races, and/or compatible wild or weedy relatives in centres
of diversity.
Other hazards to assess for plants include any increased potential
for: Weediness; effects on
non-target species; unexpected effects; worker safety.
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Need to compare LMO effects with present agricultural practices and
other options for land use.
Gene flow
occurs in all open pollinated crops, at varying frequency.
Real question is: Does it matter? Depends if new hybrids
survive to form weeds or invasive species.
LMOs may affect non-target species, but difficult to determine
significance. Need to compare LMO effects with current practices and
other options for crop cultivation.
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Baseline ecological data for comparisons are lacking.
Significance of gene flow in centres of crop diversity needs to be
investigated further. Modelling
approach may be useful to assess likelihood of gene flow and its
significance.
Effects on soil microflora are difficult to detect.
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Indirect effects
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GM
technology may change agricultural practices.
Less
insecticide used on pest tolerant crops. Instances of 40% less
insecticide used on Bt cotton.
Need to
avoid development in resistance in pest populations by crop management
systems to reduce selection pressure on target pest in Bt crops.
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Herbicide use may increase or decrease with use of herbicide tolerant
crops. Weed biology may
change in GM crop fields.
Herbicide tolerant crops may be useful for low-till agriculture and
improve soil conservation.
Stress tolerant crops may threaten
ecosystems (e.g. salinity tolerant rice in mangrove ecosystems).
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Pest-resistance management in complex agricultural systems in less
developed countries may be difficult.
Need to develop integrated pest management systems, incorporating LMOs
where appropriate, and monitor for any changes in populations of
beneficial organisms and developments in pest resistance.
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Methods of environmental impact assessment
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Types of data
sought for environmental impact assessment are similar, but
interpretation varies in different regulatory systems.
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Precautionary approaches to manage uncertainty require that new
technologies demonstrate no harm. Since biological systems do not
deliver certainty, zero risk is an unattainable standard.
Significance of laboratory studies is debatable, as it is difficult to
extrapolate from laboratory to field studies and effects of commercial
use.
What constitutes an adverse environmental impact?
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Need comparative analysis of different systems (LMOs, intensive,
subsistence, and/or organic agriculture).
Baseline
ecological data for different agricultural systems are difficult to
obtain.
Need international harmonization of environmental impact assessment
methods and commonly agreed standards.
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Biodiversity conservation
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Molecular methods
help characterize biodiversity. Genomic studies will help identify genes within species and how
to switch them on/off.
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Increasing
efficiency of agriculture may threaten biodiversity; it may also protect
biodiversity by reducing pressure on natural resources.
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Molecular finger-printing of gene bank accessions would be useful, to
set baseline data and monitor any genetic changes over time.
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New Genetics, Food &
Agriculture: Scientific Discoveries - Societal Dilemmas