Pesticides and Fertilizers Linked to Premature Births

Pesticides and Fertilizers Linked to Premature Births



 
May 2007 -   The rising premature birth rate 
in the United States is associated with increased use of pesticides and 
fertilizers containing nitrates, according to research by a professor of 
clinical pediatrics at the Indiana University School of Medicine. 
Paul Winchester, MD, reports his findings today at the Pediatric Academic 
Societies' annual meeting in Toronto, Canada, a combined gathering of the 
American Pediatric Society, the Society for Pediatric Research, the 
Ambulatory Pediatric Association, and the American Academy of Pediatrics. 
"A growing body of evidence suggests that the consequence of prenatal 
exposure to pesticides and nitrates as well as to other environmental 
contaminants is detrimental to many outcomes of pregnancy. As a 
neonatologist, I am seeing a growing number of birth defects, and preterm 
births, and I think we need to face up to environmental causes," said Dr. 
Winchester. 

Dr. Paul Winchester is a professor of clinical pediatrics at the Indiana 
University School of Medicine and medical director of Newborn Intensive 
Care Services at St. Francis Hospital, a community hospital in 
Indianapolis. 
A premature baby is born before the 37th week of pregnancy. Premature 
birth occurs in between eight to 10 percent of all pregnancies in the 
United States. 
The rate of premature birth in the United States has risen about 30 
percent between 1981, when the government began tracking premature births, 
and 2005, according to the National Center for Health Statistics, a 
division of the Centers for Disease Control and Prevention. 
The prematurity rate was 9.4 in 1981; it has increased every year since 
then except for slight dips in 1992 and 2000. 
Winchester and his colleagues found that preterm birth rates peaked when 
pesticides and nitrates measurements in surface water were highest, from 
April through July, and were lowest when nitrates and pesticides were 
lowest, in August and September. 
More than 27 million U.S. live births were studied from 1996-2002. Preterm 
birth varied from a high of 12.03 percent in June to a low of 10.44 
percent in September. 
The highest rate of prematurity, 11.91 percent, occurred in May and June 
and the lowest, 10.79 percent in August and September. These results were 
independent of maternal age, race, education, marital status, alcohol or 
cigarette use, or whether the mother was an urban, suburban or rural 
resident. 
Pesticide and nitrate levels in surface water were also highest in 
May-June and lowest in August and September, according to the U.S. 
Geological Survey. 
"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 said. 
Premature baby in an incubator, a controlled safe environment where it can 
grow until it is functioning independently. 
Because they are born too early, premature babies weigh much less than 
full-term babies. They may have health problems because their organs did 
not have enough time to develop and need special medical care in a 
neonatal intensive care unit, where they stay until their organ systems 
can work on their own. 
"I believe this work may lay the foundation for some of the most important 
basic and clinical research, and public health initiatives of our time," 
said James Lemons, MD, professor of pediatrics at the IU School of 
Medicine. 
Dr. Lemons is director of the section of neonatal-perinatal medicine at 
the IU School of Medicine and heads the Riley Hospital for Children of 
Clarian Health's section of neonatal-perinatal medicine. 
"To recognize that what we put into our environment has potential pandemic 
effects on pregnancy outcome and possibly on child development is a 
momentous observation, which hopefully will help transform the way 
humanity cares for its world," Lemons said. 
In young infants, ingestion of nitrates, components of fertilizers that 
are often washed into surface water and groundwater, can reduce the 
blood’s ability to carry oxygen. 
Today it is possible to minimize fertilizer applications. Mounted on a 
high-clearance sprayer, this crop canopy sensors monitor plant greenness, 
which is translated into a signal by an onboard computer that controls the 
application rate of nitrogen fertilizer to the soil. 
The association between nitrate-contaminated well water and inability of 
the blood to carry oxygen was first described by Hunter Comly, an Iowa 
City physician during the early 1940s. 
In 1974, the Safe Drinking Water Act set a maximum contaminant 
concentration for nitrates of 10-milligram per liter for public water 
supplies, but it does not apply to private wells. 
In a 1994 survey of 5,500 private water supplies in nine Midwestern 
states, 13 percent of the wells were found to have nitrate concentrations 
greater than the standard. 
The state of Wisconsin is well aware of the problems nitrates in drinking 
water can cause for premature babies, especially in rural areas. In 2006, 
the state Department of Natural Resources, DNR, issued a warning that 
nitrates that are washed into groundwater from fertilizer can be dangerous 
to infants, and especially to premature infants. 
"All infants less than six months of age are at risk of nitrate toxicity, 
but premature babies and babies with other health problems are more 
sensitive than healthy infants," the DNR said. 
Well owners are advised that the only way to know if their drinking water 
contains nitrate is to have a water sample tested by a certified 
laboratory. Testing is recommended for well water used by pregnant women 
and is "essential for a well that serves infants under six months of age," 
the DNR says. The DNR provides a list of certified labs online at: 
dnr.wi.gov/ org/es/science/lc. 
The state of Indiana Department of Natural Resources does not address this 
issue. 
At the Yakima Agricultural Research Laboratory in Wapato, Washington, a 
technician applies a test pesticide to a rapeseed variety being grown for 
canola oil production. 
For the past four years, Winchester and colleagues have focused attention 
on the outcomes of pregnancy in Indiana and the United States in relation 
to environmental pesticides and nitrates in surface and drinking water. 
Last year at the Pediatric Academic Societies' annual meeting, Dr. 
Winchester reported that 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 presentation expands upon that work. 
Collaborating with Dr. Winchester on this study were Akosua Boadiwaa 
Adu-Boahene and Sarah Kosten of the IU School of Medicine, Alex Williamson 
of the U.S. Geological Survey, and Ying Jun, PhD of the University of 
Cincinnati. 
The work was funded by the Division of Neonatology, Department of 
Pediatrics of the IU School of Medicine.    

       
      

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