An in-depth review of 25 studies conducted over nearly 50 years has revealed a concerning link between pesticide exposure and lower sperm concentrations in adult men around the world. This research has been hailed as the most comprehensive systematic review on the topic to date. The team, comprised of researchers from Italy and the United States, has recommended reducing exposure to two types of pesticides in order to preserve male fertility.
Lauren Ellis, a population health scientist at Northeastern University and the first author of the study, emphasized the critical nature of understanding how pesticides affect sperm concentration in humans due to their widespread presence in the environment and documented reproductive risks.
The team analyzed data from 1,774 adult men across four continents (Asia, North America, South America, and Europe) and 21 study groups exposed to organophosphates and N-methyl carbamate. The main mode of toxicity of these commonly used insecticides is the inhibition of enzymes involved in the normal breakdown of neurotransmitters such as acetylcholine.
Furthermore, the researchers noted that other studies have shown a decline in semen quality over time. A recent review found that the average sperm count among non-infertile participants decreased by 51% between 1973 and 2018, from 101.2 million to 49 million per milliliter of semen. This decline falls within the “normal” range defined by the World Health Organization. Low sperm concentration has also been associated with an increased risk of certain types of cancer. However, the mechanism behind these effects and their causation has yet to be fully understood.
In addition to pesticide exposure, other factors such as air pollution have also been linked to decreased sperm production in both humans and animals. Recent research on mice has suggested that pollution leads to a loss of sperm production through inflammatory processes in their brains.
The study recommends further research on glyphosate, a component of organophosphates, due to its neurotoxic effects. The team suggests that more robust data on its effect on sperm production is necessary. Similarly, there are limited studies on N-methyl carbamate, but the available results still establish a clear link between pesticide exposure and lower sperm concentrations.
The study was published in the journal Environmental Health Perspectives and is a crucial addition to the growing body of research on the impact of pesticides on male fertility. Source: ScienceAlert