A comprehensive analysis of studies spanning the last 50 years has revealed a worrying trend: the widespread use of certain pesticides is contributing to a significant global decline in male sperm count. Senior study author Melissa Perry, Dean of the College of Public Health at George Mason University, highlights a 50% reduction in sperm concentration worldwide over this period.
The study focuses on two commonly used insecticides: organophosphates and N-methyl carbamates. Organophosphates, ingredients in various products from nerve gas to household insecticides (including Roundup and Ortho), are ubiquitous in agriculture and domestic settings. N-methyl carbamates, similarly, used in insecticides for various crops, operate by damaging insects’ nervous systems.
Dr. Alexander Pastuszak of The University of Utah School of Medicine, not involved in the study, emphasizes the growing evidence linking these compounds to reduced male fertility. However, he notes the difficulty in directly correlating these pesticides with decreased fertility until attempts at conception occur.
The study, published in Environmental Health Perspectives, analyzed 20 research papers meeting its criteria. These studies encompassed 1,774 men from 21 different populations, revealing that higher exposure to these pesticides, such as in agricultural workers, correlates with significantly lower sperm concentration.
“Over the course of 50 years, sperm concentration has fallen about 50% around the world.
“What is not known is the culprit. While there are likely many more contributing causes, our study demonstrates a strong association between two common insecticides —organophosphates and N-methyl carbamates — and the decline of sperm concentration.
“They are widely used in agriculture on the crops we eat. We use them in structural applications within homes and buildings, apartment buildings, as well as for ornamental lawn upkeep. They’re available for consumer purchase, so organophosphate exposures have been demonstrated to be relatively widespread.”
Sperm concentration and count are critical indicators of male fertility, with concentration adjusting for variances in semen volume. Animal studies suggest these pesticides may disrupt sexual hormones, damage testicular cells, and alter brain neurotransmitters that regulate sperm production.
Perry advises caution regarding insecticide exposure, particularly for those planning families. Beyond pesticides, researchers are investigating other factors like obesity, poor diet, chronic diseases, environmental toxins, and even mobile phone radiation as potential contributors to declining sperm counts.
A recent study linked frequent mobile phone use to higher risks of low sperm counts and concentrations. Additionally, advocacy groups criticize major food manufacturers for not reducing pesticide levels in their products as promised.
Experts recommend several measures to reduce pesticide exposure from food. Choosing organic products, which generally have little to no pesticide residue, is one effective strategy. If organic options are unaffordable or unavailable, thorough washing and peeling of produce can also diminish pesticide levels. The Environmental Working Group publishes an annual guide to help consumers identify produce with the highest and lowest pesticide residues.
“As we sort of start to close the net around factors that could negatively impact fertility, these pesticides start to rise to the top,” said Dr. Alexander Pastuszak, an assistant professor of surgery and urology at The University of Utah School of Medicine.
“There’s enough evidence to really start to say yes, these types of compounds can negatively affect fertility in men,” he stated.
The US Food and Drug Administration offers additional guidelines for washing produce:
- Use warm water and soap for handwashing
- Rinse fruits and vegetables before peeling
- Use a vegetable brush for firm produce
- Dry with a clean cloth or paper towel to further reduce bacteria
In summary, the increasing evidence of pesticides’ role in declining sperm counts presents a significant public health issue. It highlights the need for more stringent regulations on pesticide use and greater public awareness of the ways to mitigate exposure. This issue underscores the interconnectedness of agricultural practices, environmental health, and human reproductive health, calling for a holistic approach to address these challenges.
