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
"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
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
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.