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
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
As the writing on the wall becomes clearer, the high price of corn
is steeper than we could ever have imagined.