Hope Not Hype - Third World Network

Pesticides
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These data for [transgenic HT] beet and soybean also show that it is not always possible to
extrapolate directly from the data previously assessed for the impacts of the same crops in the
USA owing to differences in agricultural practices in the various regions (Kleter et al., 2008,
p. 487).
Herbicide statistics are also conflicting. On a weight or volume basis, the amount of
herbicide used may have dramatically increased in the US where both the most GM crops
and statistics are available (FOE, 2008; Pretty, 2001).
These figures are disputed. Cerdeira and Duke (2006) cite research that calculates a
net replacement of 3.27 million kg of other herbicides with only 2.45 million kg of
glyphosate-type herbicides in US soybean fields, and other research showing a net 17
million kg reduction across all relevant crops in the US because of GM crops.
A problem with this debate is that the comparisons are usually between conventional
and GM agricultural technologies, both of which are pesticide-intensive choices compared
with organic and integrated pest management (IPM) technologies.
[A] GM technology resulting in reduced use of pesticides could be more sustainable than a
conventional system relying on pesticides, but this GM/reduced-use system would score less
well if compared with an organic system that used no pesticides (Pretty, 2001, p. 255).
Comparing GM only to agrochemical-intensive conventional agriculture inflates the
benefits of existing GM crops.
Much larger reductions in per ha insecticide use have been achieved by farmers using integrated
pest management methods in both the tropics and temperate regions (Pretty, 2001, p. 256).
Two issues stand beyond this debate over quantities of pesticide used. First, there is
universal agreement that more of the herbicide glyphosate is used now compared to any
other time in the past, with the most dramatic increases in use corresponding to the
introduction of GM crops (Kleter et al., 2007; Service, 2007). Second, the pattern of use of
agrochemicals is different from pre-GM crop use and this is creating unique problems in
the agroecosystem and beyond (e.g., for insecticides see Appendix Three and for herbicides
see Graef et al., 2007; Powles, 2008; Young, 2006).
Human health and environmental risks from insecticidal crops
The predominant insecticide produced by insecticide-producing crops is a variant of
one or more toxins sourced from genes carried by small infectious genetic elements, called
plasmids, found in soil bacteria known as Bacillus thuringiensis (i.e., Bt). B. thuringiensis
is closely related to Bacillus cereus and Bacillus anthracis. Members of this group are so
closely related that they may be considered members of the same species, often differing
only by the presence or absence of particular plasmids which may be exchanged between
them and which define the particular kinds of diseases for which the different bacteria are
known (Helgason et al., 2000a; Helgason et al., 2000b; Hoffmaster et al., 2004).