A Corn with Eight New Genes - Safe?

Aug 12, 2009

The Environmental Protection Agency approved a new type of genetically modified corn this month called SmartStax'. The new corn - from Monsanto and Dow AgroSciences - was genetically engineered to include eight new genes in its genome. Six genes to produce pesticide, two genes to resist herbicide.

It's the first time the EPA approves an eight-gene corn. In the past, the EPA approved genetically modified corn with only two extra genes, three at most.

But some people think the EPA has been too quick with the approval. Policy analyst Bill Freese at the Center for Food Safety in Washington worries the corn will spur the evolution of superbugs - insects resistant to conventional pesticides.

"First of all the EPAs decision on these crops is based almost exclusively on studies that are done by the companies that are applying for approval of the crops and that has given rise to bias," says Freese.

BT is a pathogen found naturally in soil. It's toxic to many insects, and so it's been used as a spray-on pesticide for years.

Genetically modified corn like SmartStax is engineered to include the BT gene in its genome. As it grows, the corn plant produces its own dose of BT pesticide.

The concern is some insects in a population of Root Worm, for example, are naturally more resistant to BT. Freese says the genetically strong insects that survive could mate -- producing offspring with even more resistance to BT.

"There's a great concern among organic farmers that development of resistance could make BT sprays useless," says Freese.

The EPA says the chances of this happening are low because it mandates growers to use a refuge'. Mike Mendelson from the EPA explains a refuge is a portion of land growers devote to non-BT corn.

"If resistance were to develop to the BT-corn the refuge provides non-resistant insects that could dilute that potential resistance," says Mendelson.

But that's true only if the refuge is big enough. The concern with SmartStax is that it isn't.

In the past, growers had to devote 20% of their field for the refuge. With SmartStax however, the EPA reduced the requirement to 5%. Freese says it was an unwise decision for the EPA to reduce the requirement.

"Obviously I think we need to take an independent study with a greater seriousness than one completed by a self interested company," says Freese.

Professor of Crop Sciences at Ohio State, John Finer is one of those who stand behind the SmartStax science. Finer says it's because SmartStax combines - or stacks' - many pesticide genes into one plant.

"What we see in the laboratory is a "Yes, you can have insects that eventually develop a resistance". As you stack starting more genes, the numbers get incredibly low, infinitesimally small," says Finer.

Even if 5% were large enough for a refuge, Freese says he's also concerned about grower compliance.

The enforcement of these refuge requirements is left to the industry and often enough these refuge requirements aren't followed,' says Freese.

A consortium of companies including Monsanto and Dowe says grower compliance is about 90%. Monsanto's Joanne Carden says the company arrived at that number by sending an online survey to its growers and by on-site assessments.

Growers are randomly selected, and it's a face to face interview. We could look at invoices to see if they have properly purchased refuge seeds, and all that type of information', says Carden.

Monsanto - citing anti-trust measures - won't say how many assessments are completed each year.

"All I can say at this point is that it's statistically significant for that particular growing years,' says Carden.

Danita Murray from the National Corn Growers Association says her association welcomes the EPA's approval. Murray says the technology could boost a grower's bottom line.

But ultimately, it's up to growers to decide whether they'll harvest the new genetically engineered corn.

I simply can't predict, obviously that's an individual decision each grower will make for themselves based on their own operation,' says Murray.