Parents, don't blame your children anymore for low test scores. According to American research, lesser grades in children are linked to the time of their conception-which unfortunately they can't help.
Announcing results of a first-time study, Dr. Paul Winchester of Indiana University School of Medicine claimed that children conceived from May through August were bound to perform worse than their peers in examinations.
The researchers linked standardized test scores of 1,667,391 Indiana students in grades 3 through 10 with the month in which each student had been conceived. The report presented at the Pediatric Academic Societies' annual meeting, showed that regardless of race, gender, and grade level, children conceived from May through August scored significantly lower on math and language tests- than children conceived during other months of the year.
According to the scientists, lower test scores were found to correlate with higher levels of pesticides and nitrates in the surface water (nearby streams and other bodies of water) during that same time period. Pesticides and nitrates are used on crops and lawns in the warmer months, and they could have an effect on the earliest development of fetal brains, postulates Winchester.
"Exposure to pesticides and nitrates can alter the hormonal milieu of the pregnant mother and the developing fetal brain," says Winchester. He quoted previous studies linking exposure to pesticides and nitrates to low thyroid hormone levels ("hypothyroidism") in pregnant women. Hypothyroidism in pregnancy incidentally, has been tied to lower intelligence test scores in offspring.
While the current findings do not prove that pesticides and nitrates contribute to lower test scores, "they strongly support such a hypothesis," Winchester says.
"A priori there should be no reasons particularly why the month of conception should change your (test) scores. Yet from our chain of evidence our hypothesis was that if pesticides do alter the friendly environment of the developing fetus than that might be reflected in lower scores. And unfortunately that's what we found", Winchester was quoted.
According to the scientists, the fetal brain begins developing soon after conception. The pesticides used to control pests in fields and homes and the nitrates used to fertilize crops and even lawns are at their highest level in the summer.
According to the American Pregnancy Association, even household gardening pesticides are well-known to put pregnant women at high risk for many birth defects, including oral clefts, neural tube defects, heart defects, and limb defects.
While domestic pesticides are the fastest growing segment of the pesticide industry, a correlation exists between all pesticide exposure and birth defects.
"We actually found that every single birth defect category had a greater risk between April and July," Winchester said. "It suggests that with seasonal factors, something is conferring increased risk."
And it is not just risk for birth defects; according to Winchester, the number two cause of infant mortality in the U.S.- premature birth, also peaks along with pesticide use.
The evidence in this latest study shows that the trend in pesticide exposure, especially pesticides found in drinking water, is related to trends in test scores many years down the road.
"We have now linked higher pesticide and nitrate exposure in surface water with lower cognitive scores," Winchester was quoted. "Neurodevelopmental consequences of exposure to pesticides and nitrates may not be obvious for many decades."