(Beyond Pesticides, April 1, 2009) A study published in the April 2009 issue of the medical journal Acta Paediatrica reports that the highest rates of birth defects for U.S. babies arise when conception occurs during the spring and summer months, when pesticide use increases and high concentrations of pesticides are found in surface waters.
The study entitled, “Agrichemicals in surface water and birth defects in the United States” is the first study to link increased seasonal concentration of pesticides in surface water with the peak in birth defects in infants conceived in the same months. Researchers analyzed all 30.1 million births in the U.S. between 1996 and 2002. A strong association between higher rates of birth defects among women whose last menstrual period was in April, May, June or July and elevated levels of nitrates, atrazine and other pesticides in surface water during those same months was found.
The correlation between the month of last menstrual period and higher rates of birth defects is statistically significant for half of the 22 categories of birth defects reported in the Centers for Disease Control database from 1996 to 2002, including spina bifida, cleft lip, clubfoot and Down’s syndrome.
“Elevated concentrations of pesticides and other agrochemicals in surface water during April through July coincided with significantly higher risk of birth defects in live births conceived by women whose last menstrual period began in the same months. While our study didn’t prove a cause and effect link, the fact that birth defects and pesticides in surface water peak during the same four months makes us suspect that the two are related,” said Paul Winchester, M.D., Indiana University School of Medicine professor of clinical pediatrics, the first author of the study.
The study relies on findings by the U.S. Geological Survey, the U.S. Environmental Protection Agency and other agencies on the seasonal variations in nitrates, atrazine and other pesticides in the surface water. Pesticides, such as atrazine, even at low levels, have been associated with reproductive and developmental effects as well as endocrine disruption. Atrazine is the second most commonly used agricultural pesticide in the U.S. and the most commonly detected pesticide in rivers, streams and wells. An estimated 76.4 million pounds of atrazine are applied in the U.S. annually. Atrazine has a tendency to persist in soils and move with water, making it a common water contaminant.
Birth defects are known to be associated with risk factors such as alcohol, smoking, diabetes or advanced age. However, the researchers found that even mothers who didn’t report these risk factors had higher overall birth defect rates for babies conceived from April to July. “Birth defects, which affect about 3 out of 100 newborns in the U.S., are one of the leading causes of infant death. What we are most excited about is that if our suspicions are right and pesticides are contributing to birth defect risk, we can reverse or modify the factors that are causing these lifelong and often very serious medical problems,” said Dr. Winchester.
This is not the first documentation of birth defects resulting from pesticide exposure during pregnancy. In 2004, three female farmworkers gave birth to babies with severe birth defects after being exposed to pesticides. One baby was born without arms or legs and with spinal and lung deformities. See previous Daily News stories.
Source: U.S. News and World Report