Despite evidence that transgenes (from species other than the “engineered” species) in genetically modified (GM) plants can persist in the soil, little research has been done to determine the extent of such contamination. This is an important issue because environmental contamination by transgenes “hasseri- ous implications for environmental health, including human safety,” according to Canadian scientists who recently tested various soil-dwelling animals for the transgene (responsible for resistance to the herbicide glyphosate) present in GM Roundup Ready® corn. They collected the animals in May, August, and October (macroarthropods and nematodes) or in May and Au- gust (microarthropods and earthworms) from a field of Round- up Ready® corn.

The transgene was present in all types of ani- mals on all collection dates, with the exception of nematodes collected in August. About 81% of nematodes collected in Oc- tober tested positive for the transgene. More than one-third of microarthropods (thrips, collembolans, and mites) tested posi- tive. And slightly more than 10% of macroarthropods (mostly various insects) and earthworms tested positive. Concentrations of the transgene tended to decrease in nematodes and earth- worms and to increase in arthropods during the growing sea- son. Levels of the transgene in the soil (free of plant tissues) were usually considerably lower than levels in the animals.

The scientists who conducted this experiment rather matter- of-factly note: “Whether the presence of transgenes in the soil food web presents a risk for soil animals is not known.” We ad- mit to being quite astounded by this statement, which appears to indicate that GM crops are being used far and wide without a clear understanding of their effects on the environment! The bottom line is that (for the first time after years of commercial cropping of GM plants) there is “evidence for large concentra- tions of transgenic DNA in animals from the food web associat- ed with RoundUp Ready® corn. This indicates that the trans- gene does not significantly degrade within the food web. Fur- ther, the guts of these animals may provide opportunity for genetic transformation into native soil bacteria.” And that last “opportunity” might lead to movement of transgenes into non- GMplants and ultimately pose risks to human health.

It could very well be the case that the commercialization of GM crops will produce animals containing genes that could do great harm to humanity. A perhaps enormously problematic can of worms (and bugs), indeed!

Reference: Miranda M. Hart (Dept. of Integrative Biology, Uni- versity of Guelph, Guelph, Ontario, CANADA N1G 2W1), et al., “Detection of Transgenic cp4 epspsGenes in the Soil Food Web,” Agronomy for Sustainable Development 29(4), October/ December 2009, 497-501. (EDPSciences, 875 Massachusetts Ave., 7th Floor, Cambridge, MA 02139.)