America’s increased use of pesticides and nitrates, which end up in surface water and have a seasonal pattern, has been linked to the nation’s growing rate of premature births, which also follows a similar seasonal pattern.

These are the conclusions of Dr Paul Winchester, professor of clinical pediatrics at the Indiana University (IU) School of Medicine who revealed his findings this week at the annual meeting of the Pediatric Academic Societies in Toronto, Canada.

Dr Winchester and colleagues Akosua Boadiwaa Adu-Boahene and Sarah L Kosten, also of the IU School of Medicine, Alex K Williamson of the US Geological Survey, and Dr Ying Jun, of the University of Cincinnati, found that premature birth rates peaked when levels of pesticides and nitrates in surface water were at their highest from April to July, and were lowest when the chemicals were also at their lowest levels in August to September.

The team studied over 27 million live American births occurring between 1996 and 2002. The percentage of babies born prematurely in that period peaked in June (12.03 per cent) and was lowest in September (10.44 per cent). The highest rate of preterm births took place from May to June (11.91 per cent) and the lowest rate from August to September (10.79 per cent).

The correlation between premature birth rates and levels of nitrates and pesticides was independent of the mothers’ age, race, education, marital status, alcohol consumption and smoking status. The link was also independent of whether the mothers lived in urban, suburban or rural places.

The US Geological Survey showed that pesticide and nitrate levels in surface water were also at their highest from May to June, and at their lowest from August to September, a pattern consistent with the preterm birth levels over the same study period.

Last year Dr Winchester and his team revealed the results of an earlier 4 year study into pregnancy outcomes in Indiana and the US where significant links were made between seasonal levels of pesticides and nitrates in surface and drinking water and seasonal levels of birth defects.

Dr Winchester is a neonatal specialist and director of Newborn Intensive Care Services at St Francis Hospital in Indianapolis. He is disturbed by what he sees as the growing number of birth defects and pre-term babies, which he puts down to growing levels of pesticides and nitrates that end up in surface and drinking water:

“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.”

“We need to face up to environmental causes,” he added, explaining that:

“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 US. Nitrates and pesticides can disrupt endocrine hormones and nitric oxide pathways in the developing fetus.”

Dr James Lemons, Hugh McK Landon Professor of Pediatrics and director of the section of neonatal-perinatal medicine at the IU School of Medicine, and head of neonatal-perinatal medicine at Clarian Health’s Riley Hospital for Children in Indianapolis, said of Dr Winchester’s findings:

“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.”

“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,” he added.

The annual meeting of the Pediatric Academic Societies brings together scientists from the American Pediatric Society, the Society for Pediatric Research, the Ambulatory Pediatric Association and the American Academy of Pediatrics.

Pesticides and herbicides used in agriculture are primarily organic chemicals and can end up in surface water due to run off from row crops. There are other ways that potentially dangerous organic compounds can end up in surface and drinking water, such as leaching from storage tanks, factory discharge, landfills, emissions from waste incineration, discharge from petroleum and metal refining, textile finishing, and various other industrial processes.

Ingesting water contaminated with organic pesticides and herbicides causes a range of potentially serious health problems depending on the chemical, but a quick scan down the US Environmental Protection Agency’s (EPA) list of organic drinking water contaminants shows many of these to be linked to organ damage and other serious illnesses such as cancer and cardiovascular problems.

Click here to go to US EPA’s list of Drinking Water Contaminants.

Click here for Prematurity, a Preemie Parent Support site run by volunteers (US based).

Written by: Catharine Paddock
Writer: Medical News Today