Indiana study indicates possible pesticide link to birth defects
April 4, 2009
Pesticides may increase the risk of birth defects, say researchers who found the highest rates of birth defects in American babies among those conceived in the spring and summer, the same time that there are increased levels of pesticides in surface water.
Researchers from Indiana University published their findings in the April issue of the medical journal Acta Paediatrica.
Studying all 30.1 million births that occurred in the United States between 1996 and 2002, the research team found a strong association between the increased number of birth defects in children of women whose last menstrual period occurred in April, May, June or July, and elevated levels of nitrates, atrazine and other pesticides in surface water during the same months.
Many of the chemicals, including the herbicide atrazine which is banned in Europe but permitted in the United States, are suspected of being harmful to the developing embryo.
This was the first study to link an increased seasonal concentration of pesticides in surface water with a peak in birth defects in infants conceived during the same months.
The correlation between the month of last menstrual period and higher rates of birth defects was statistically significant for half of the 22 categories of birth defects, 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,” said lead researcher Paul Winchester.
“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,” Winchester said.