Minnesota health officials will evaluate the health risks of a highly popular farm herbicide.

Glyphosate is the main ingredient in Roundup, which is widely applied to fields growing genetically modified corn and soybeans. The International Agency for Research on Cancer found last year that glyphosate is 'probably carcinogenic to humans'.

The state health department's Jim Kelly said the agency will review toxicity studies for the herbicide.

"I'm anticipating there would be enough information for us to derive a guidance value," said Kelly. "That's just the level that tells us above which there could be some small risk from exposure."

An estimated 90 percent of the nation's corn and soybeans come from plants genetically modified to tolerate Roundup, which kills weeds without harming the crops. The Minnesota agriculture department says the use of glyphosate will likely increase in the future. The agency says its most recent data shows about 28 million pounds of the herbicide were sold in Minnesota in 2011.

The health department study will also examine a glyphosate by-product, aminomethylphosphonic acid or AMPA, for possible toxicity.

Kelly said the glyphosate review can take up to six months. The health department has examined as many as a dozen other farm pesticides over the last five years.