US agency endorses GM crops

The EPA judges Bt risks to Monarchs as low

By environment correspondent Alex Kirby

Support for the embattled biotechnology industry has come from an influential quarter - the US Environmental Protection Agency.

The EPA says several widely-used genetically-modified crops offer "significant benefits" and few risks.

A draft EPA report says the GM crops pose little danger to wildlife and are safe for human consumption.

But the agency will continue to monitor further research on the plants' possible effects.

Its report is an assessment of the risks and benefits of growing Bt crops, plants which have been modified to contain Bacillus thuringiensis.

Review

This is a naturally occurring soil bacterium which acts as a pesticide against insects, including the European corn borer and the bollworm.

The EPA prepared the assessment as part of its review of the registrations for several GM crops, including potatoes, cotton and corn.

A Cornell University study last year found that the pollen of Bt corn was toxic to Monarch butterflies in the laboratory.

Buffer strips round Bt fields are urged

Last month, researchers at Iowa State University said they had found Monarch caterpillars were seven times likelier to die when they ate milkweed plants dusted with pollen from Bt corn rather than conventional corn.

But the EPA says: "Considering all of the information available, the weight of evidence indicates no unreasonable adverse effects to non-target wildlife, plants, or beneficial invertebrates.

"The available information indicates a very low probability of risk to Monarchs in areas beyond the near-edge of cornfields.

"The agency concludes that the published preliminary Monarch toxicity information is not sufficient to cause undue concern of widespread risks to Monarch butterflies."

Health benefits

The study says the risk to the butterflies range from low to very little, depending on whether they are feeding inside or around the perimeter of the corn fields.

Studies say Monarch caterpillars may be at risk

It says the corn itself shows relatively low toxicity to the Monarchs, and also examines the crop's impact on ladybirds, rodents and other creatures.

On human health, it says the assessment "confirmed the EPA's original findings that there are no unreasonable adverse effects from these products."

The EPA goes further than saying Bt crops are unlikely to be harmful: it says some will probably be positively beneficial.

"The EPA believes that significant benefits accrue to growers, the public and the environment from the availability and use of certain Bt plant pesticides", it says.

Buffer strips

The EPA says that farmers saved more than $100m on chemical pesticides last year.

"For Bt corn products, the major benefits predicted were an increase in yield, and for Bt cotton and potatoes they were a reduction in the use of chemical insecticides."

The EPA says that after five years of use by US farmers no cases of insect resistance have been found with Bt corn, cotton or potato plants.

The assessment, which also contains recommendations for protective buffer strips around Bt fields, will be discussed by the EPA's scientific advisory panel in October.

Bt crops planted by US farmers last year totalled about 8m hectares (20m acres) of corn, 1.5m hectares (3.6m acres) of cotton, and 20,200 hectares (50,000 acres) of potatoes.