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Transcript
Toxicological Assessment
Heinz Hofer
ARC Seibersdorf research GmbH
Department of Toxicology
S E I B E R S D O R F
Some results of the dossier evaluations
 Extent of the toxicological investigations: no marked
differences between 90/220/EEC and 258/97/EC.
 An acute oral toxicity study was performed with each
newly inserted protein, in most cases.
2
Some further results, 1
 Other usually investigated toxicological endpoints, as e.g.
repeated dose toxicity, chronic toxicity, genotoxicity,
reproduction toxicity, malformations of new-borns or
carcinogenicity were not investigated.
 No systematic risk assessment was performed (with one
exception).
3
Methods of risk assessment
First source
The application of the principle of Substantial
Equivalence was the main method to show a low
risk of the GM plant
4
Methods of risk assessment
Second source
Assumption based reasoning
- and not only fact based reasoning was observed repeatedly, to produce favourable
statements.
5
Example for assumption based reasoning
"This food has been used commercially for 4 years, and 300
million Americans are currently eating it with no sign of a
problem.“
This statement was taken then as an argument for the safety
of the GM food.
6
Critique
The opinion on lacking toxic effects of the GMP is
not the result of extensive toxicological studies, but
is an opinion that could arise, when missing results
due to missing investigations are misinterpreted as
"non-toxic" effects.
7
Critique
Opinions like
"no signs of a problem" or
"long history of safe use"
are by no means proofs for safety.
8
From the EU Recommendation 97/618/EC
"Thus, foods have not hitherto been systematically
subjected to nutritional or toxicological evaluation,
except in rare cases, ...."
9
Method of risk assessment
Third source
The digestibility of the new protein was tested in
in vitro assays. Digestibility is usually fast,
indicating an only low absorption of the protein.
Critique: It is the opinion of the Scientific Committee
on Plants, that in vivo assays should be
performed (and not only in vitro assays).
10
Methods of risk assessment
Fourth source
The homology of the new protein with known toxins
or other protein was checked.
Critique: An identity of only ca. 50 % of the amino
acid sequence of the new protein with a well
known protein, was taken as a “proof” for the low
toxicity.
11
Some further results, 3
Underdeveloped regulations and guidance documents on
 testing methods,
 data requirements,
 dossier preparation,
 risk assessment,
 decisions on authorisation,
 quality aspects,
compared to other regulated products.
12
Recommendations, 1
 To dismiss the principle of substantial equivalence, as it is
not ascertained that the conventional counterparts are
safe.
 Instead of, to require toxicological investigations of the
whole GMPs, to cover also other toxicological endpoints,
e.g. carcinogenicity.
Possible secondary effects could be detected when the
whole food plant is investigated.
13
Recommendations, 2
 The risk assessment of GM crops should be based on
toxicological results and on the estimated exposure.
 To create guidance documents on







data requirements
dossier preparation
risk assessment
authorisation
standard formats
standard testing methods
Good Laboratory Practice
14
Recommendation, 3
The updated risk assessment and authorisation
procedure of GMPs should be a starting point of the
systematical toxicological evaluation of
traditional food plants,
which is overdue.
15