A recent study found that exposure to environmental chemicals in early life may affect men's reproductive health into adulthood, causing genetic abnormalities in sperm
Studies conducted on animals have previously shown that continuous exposure to certain chemicals during early life stages may negatively affect male fertility, but human evidence was limited until recently.
A study conducted by environmental epidemiologist Melissa Berry and her research team revealed a link between exposure to chemicals during pregnancy and childhood and sperm abnormalities in adults. This study is among the first to track this effect across a lifespan spanning from prenatal to adulthood.
Healthy sperm plays a crucial role in reproduction, ontaining the 23 chromosomes that make up human genetic material. However, researchers found that some participants exposed to higher levels of certain chemicals early in life had sperm containing extra chromosomes, which could increase the risk of miscarriage or birth defects such as Klinefelter syndrome.
Perry, dean of the George Mason University School of Public Health, said: "These findings provide new evidence that exposure to chemicals in the embryonic stage and beyond may have a lasting impact on sperm DNA integrity into adulthood."
The study was based on the analysis of semen samples from men aged 22 to 24, whose mothers had provided blood samples during pregnancy between 1986 and 1987. Levels of persistent chemicals, such as polychlorinated biphenyls (PCBs) and perfluoroalkyl compounds (PFASs), were measured in the mothers' blood, and later in the sons at ages seven and fourteen.
Decades later, these men underwent semen analysis, and the results showed that high early exposure to these substances was associated with abnormalities in the number of chromosomes within sperm at puberty.
Normal sperm contain only an X or Y chromosome, but the study found that exposure to PCBs was specifically associated with the presence of an additional Y chromosome, while PFAS compounds were associated with increases in both X and Y chromosomes.
Researchers believe that the source of exposure to polychlorinated biphenyls (PCBs) may be the mother's diet, particularly through contaminated seafood, while PFAS compounds are believed to spread through food, water, and air as a result of environmental pollution.
Perry stressed that "exposure to chemicals is a public health problem, and there is growing evidence of its link to reduced sperm quality. We need policies that limit the spread of these substances in the environment and protect the reproductive health of future generations."
The study was published in the journal "Environmental Health".
