[SANET-MG] confinement of GM maize

[jcummins <jcummins@UWO.CA>]

The article below deals with confinement of GM maize. It provides 
interesting data on the spread of pollen and on the machine transfer of 
pollen and seeds. As an interesting  comment machine transfer was found 
to be many times more effective in spreading gene pollution than was 
pollen flow. My thought is that the focus of concern by government 
regulators and academe has been pollen escape and pollution of nearby 
crops. The main threat of gene pollution seems to be machine transfer 
which has been ignored or obfuscated by regulators and academe.
Environ. Biosafety Res. 3 (2004) 183-196
DOI: 10.1051/ebr:2005004
Quantitative exposure assessment for confinement of maize biogenic systems
Jeffrey D. Wolt, Yuh Yuan Shyy, Paul J. Christensen, Karin S. Dorman and 
Manjit Misra
Abstract
The development of transgenic crops as production platforms for biogenic 
agents will largely depend on the success of efforts to confine the 
genes and their expressed proteins in field environments. We have used 
quantitative exposure assessment to evaluate how management practices 
affect materials escape due to outcrossing by pollen flow or grain loss 
during harvest operations. Specifically, we study the use of maize to 
produce biogenic agents within field-confined systems. Decision trees 
representing simplified schemes of fully conforming (designed to comply 
with current regulatory standards for field confined trials), partially 
conforming, and non-conforming management practices were developed. 
Exemplifying assumptions and published data for conformance and material 
fate probabilities were used in Monte Carlo simulations to forecast 
materials escape by pollen outcrossing and harvest operations from a 1 
ha source field. Deterministic analyses showed fully conforming 
confinement management restricted materials loss to low levels (for this 
example, outcrossing produced <1 in 106 kernels in receptor fields). The 
corresponding high-end (90th percentile) probabilistic result was 16- 
and 4333-fold higher (relative to deterministic outcrossing = 1) for 
outcrossing and harvest loss, respectively. For partially conforming 
practice, high-end outcrossing ranged from 100- to >15 000-fold over the 
base result in receptor fields, and harvest loss was >10 000-fold over 
the base result. For non-conforming practice, high-end outcrossing 
produced >15 000-fold greater kernels in receptor fields and high-end 
harvest loss was at least 19 000-fold greater. Deterministic estimates 
of off-field loss by machine transfer are as much as 30 000-fold higher 
for non-conforming operations relative to the base case of pollen 
outcrossing. Better knowledge of failure frequencies for confinement 
management practices, improved physical models of materials flows, 
refined analysis of confinement loss probabilities using quantitative 
tools, and decision analysis to improve and audit management system 
performance are all needed to extend understanding of confinement 
integrity beyond the exemplifying case used here.

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