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June 15, 2007: As May turns to June, a significant portion of the U.S. heartland becomes covered by a corn blanket. With a high market price from ethanol demand, corn planting went on at a feverish rate this spring. It is estimated that more than 90 million acres of corn will be planted before the 2007 season is over. This will be the largest area since 1944 and 12.1 million acres more than in 2006.
More land in corn may have a significant human-health impact, as well, influencing children conceived during the months of peak herbicide and fertilizer application and runoff. According to Dr. Paul Winchester from the Indiana University School of Medicine, seasonal runoff periods for pesticides and nitrates used on corn fields coincide well with the conception dates for children who have lower scores on the state's academic achievement tests during their school years. These results were reported at the annual meeting of Pediatric Academic Societies in May.
Winchester is a neonatal specialist and director of Newborn Intensive Care Services at St. Francis Hospital in Indianapolis.
Indiana children conceived June through August have the lowest scores on math and language tests, based on studies of hospital and school records by University of Indiana Medical researchers. Fertilizer and herbicide runoff from corn fields into surface waters is highest during the summer months, as well.
Field to fetus
High nitrate and atrazine levels are suspected of derailing the normal production of thyroid hormones. These hormones are well known for their crucial impact on intellectual development. The earliest stages of pregnancy are the most susceptible to outside disruption of developmental processes.
The intellectual performance study was based on looking at more than 1.6 million Indiana students in grades 3 through 10. Intellectual performance was measured through the Indiana Statewide Testing for Educational Progress (ISTEP) program for both math and language. Both categories showed the same result: Children conceived between June and August when pesticide and nitrate exposures are at their peak turned in the lowest test scores. The correlation was consistent across races and genders.
"Exposure to pesticides and nitrates can alter the hormonal milieu of the pregnant mother and the developing fetal brain," Winchester was quoted as saying in a press release from the Indiana University School of Medicine. "While our findings do not represent absolute proof that pesticides and nitrates contribute to lower ISTEP scores, they strongly support such a hypothesis."
Pre-term births show correlation
In his national study, Winchester also looked at how agricultural contaminant levels in water associated with premature birth and birth-defect incidence. He commented in Medical News Today (05/09/2007), “Preterm births in the United States vary month to month in a recurrent and seasonal manner. Pesticides and nitrates similarly vary seasonally in surface water throughout the U.S. Nitrates and pesticides can disrupt endocrine hormones and nitric oxide pathways in the developing fetus."
Winchester and his research groups looked at data from 27 million births from 1996 to 2002 to identify these correlations. Premature births were 12 percent for June conception (highest for the year) compared to 10.4 percent for September conception (the lowest month). Birth defects peak in Indiana and in the United States as a whole during April through July, the same months as pesticides and nitrates reach their maximum concentrations in surface water. This year’s data from Winchester and his colleagues continues a four-year focus on pregnancy outcomes in Indiana and the U.S.
Since the 1940s, the U.S. Corn Belt has become the persistent target for large applications of synthetic fertilizers and herbicides. Besides fostering vibrant corn growth, these additives also contribute not only to the contamination of our soil, water and the air we breathe, but also to contaminating our own bodies and those of our children.
As the writing on the wall becomes clearer, the high price of corn is steeper than we could ever have imagined. 
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