In the past year, there have been a slew of studies showing that when a child is exposed to certain pesticides — whether before birth or while eating conventionally-grown food — his or her IQ may drop. Sometimes by several points.
But what does this really mean? As a society, what might the impacts be? In short, should we be worried? The answer, according to one recent study, is an emphatic and sobering “yes”.
Dr. David C. Bellinger, professor of neurology and environmental health at Harvard, took a close look at published science linking IQ impacts to three types of environmental contaminants: organophosphate pesticides, lead and methyl mercury.
I’m not a tremendous fan of statistical analysis, but this is seriously interesting stuff. Dr. Bellinger based society-wide IQ loss calculations on an estimated 25.5 million U.S. children under the age of five.
Here’s what he found:
- Exposure to organophosphate pesticides is reducing IQ by about 17 million points at the population level.
- Lead is still the most harmful environmental exposure, linked to loss of about a 23 million IQ points population-wide.
- Combined, exposure to these three types of chemicals equates to a population-wide drop of 1.6 IQ points for each child — more than 40 million points for the population as a whole.
Read More: When IQs fall