Traces of plastic microparticles found in semen samples of healthy men: prolonged exposure to plastic pollution might be putting the future of humanity at risk
Italian researchers have found plastic microparticles in human semen
A group of researchers from different Italian universities discovered plastic microparticles in the semen of healthy, non-smoking men living in a high-impact environmental area in Campania, a region in Southern Italy. Six out of ten samples of seminal fluid examined contained the particles.
The study was published as a preprint in the journal ‘Science of the Total Environment’ and presented at the congress of the Italian Society of Human Reproduction (Siru) in Syracuse. It highlights worrying factors on the escalating environmental threat concerning male fertility, so human reproduction.
It is explained that the origin of these fragments derives from substances contained in cosmetics, detergents, toothpastes, creams, adhesives, beverages, foods, and even airborne particles in the environment. These microplastics can enter the human body through ingestion, inhalation or skin absorption.
The study: ‘Raman Microspectroscopy Evidence of Microplastics in Human Semen’
Over the course of their lives, individuals can amass a significant number of microplastic particles. These minuscule fragments have been detected in various human tissues, such as hair, lungs, kidneys, liver, spleen, as well as in meconium, breast milk, placenta, blood, urine, and may pose a potential risk to human health, including reproductive health. A preliminary study made in January 2023 pinpointed four pigmented microplastic fragments (4-15 μm size) in the urine samples of six volunteers from different cities in the south of Italy (three men and three women).
The exact chemical composition of the microplastics including polypropylene (Pp), polyethylene (Pe), polyethylene terephthalate (Pet), polystyrene (Ps), polyvinyl chloride (Pvc), polycarbonate (Pc), polyoxymethylene (pom), and acrylic materials was found in semen in the most recent research. Out of the ten samples examined, six of them contained a total of 16 pigmented microplastic particles, varying in size from 2 to 6 micron with either spherical or irregular shapes.
The male reproductive system is susceptible to environmental stressors
Assessing the reproductive hazards posed by contaminants has garnered significant scientific interest, especially in light of the ongoing reproductive crisis, affecting the male reproductive system.
Male individuals residing in polluted areas have been proven to be subjected to potential transgenerational effects on molecular alterations in Sperm Nuclear Basic Proteins (SNBP), the chromosomal proteins that are found associated with DNA in sperm nuclei at the end of spermiogenesis.
Overexposure to environmental elements such as heat, toxins and industrial chemicals can reduce sperm production or sperm function, as well as the extended exposure to pesticides, herbicides, organic solvents and painting materials that may contribute to lower sperm counts.
These human data align with similar findings found in mice testing, where susceptibility to certain pollutants has been shown to increase across generations.
EcoFoodFertility: The future of our species might be at risk
Professor Montano, a specialist in uro andrology from the ASL of Salerno and the coordinator of EcoFoodFertility, explained that the discovery raises concerns about the future of our species, indicating an increasing risk on the medium that safeguards our transmissible heritage.
Considering the global decline in sperm quality witnessed in recent decades, urgent actions must be taken to prevent the exponential growth of plastic waste, which negatively impacts the reproductive system.
How microplastics are released inside the human body
The information regarding the impact of microplastic accumulation on male reproductive health is still limited. Microplastics and nano plastics have the ability to absorb and carry hazardous substances commonly used as additives in plastic production.
The toxicity associated with these microplastics depends on their size, with smaller particles having higher capacity to absorb and larger surface areas, resulting in the release of greater amounts of endocrine disrupting chemicals and toxic chemicals.
The Trojan horse effect of microplastics
This process of bioaccumulation and biomagnification in science is referred to as the ‘Trojan horse effect’ of microplastics, and they can lead to various combined changes at the behavioral, histological, and biomolecular levels.
Several endocrine disrupting chemicals present in microplastics or transported by them share structural elements with specific hormone receptors that interfere with the normal functioning of these receptors disrupting the hormonal balance in endocrine glands. However, most of these findings are based on studies conducted on animals grown in laboratories, and their applicability to natural environmental conditions remains uncertain.
Sperm quality decline is a consequence of consumerism: the diffusion of plastic
A recent literature review published in the International Journal of Environmental Research and Public Health highlighted a concerning trend of increasing male infertility since the 1940s, accompanied by a decline in semen quality.
Coincidentally, global plastic production has experienced a substantial surge from 1.5 million tons in the 1950s to 335 million tons in 2016, leading to a significant rise in the presence of microplastics.
School of Public Health, Israel: Something in our lifestyle is accountable for declining sperm count
Opinions among researchers regarding the potential impact of microplastics on human health are contrasting.
Some researchers argue that the current levels of microplastic pollution in the environment are not significant enough to affect human well-being.
However, there are other researchers who strongly believe that the increased presence of microplastics in water and food is linked to reduced sperm count and sperm quality in humans.
Dr. Hagai Levine, who leads the environmental health track at the Hebrew University-Hadassah, identifies certain lifestyle factors as part of the problem. Stress, sedentary behavior, smoking, alcohol consumption, and recreational drug use all have detrimental effects on sperm.
These factors, added to the endocrine disruptors mentioned before, interfere with the natural hormone systems in the body, including the production of the male hormone testosterone.
Is humanity doomed? Microplastics’ effects begin during embryo’s growth and development
According to Niels Skakkebæk, a professor at the University of Copenhagen and senior researcher at Rigshospitalet in Denmark, the effects of poor sperm quality can manifest even during fetal development in the mother’s womb.
It has been theorized that these conditions are linked to the mother’s exposure to environmental contaminants at critical stages of pregnancy when the baby’s sex organs are still developing.
If the sperm’s ability to swim, navigate, and fertilize an egg is compromised by plastic-derived chemicals, it will put the embryo at risk from the early stages of pregnancy.
Acknowledging the value of male reproductive health
In 2022, Professor Levine, along with fellow scientists, public health officials, and clinicians from various countries, released a statement urging governments, scientific and medical communities and organizations to dedicate resources towards investigating these concerns and implementing policies that eliminate hazards and foster a safer environment.
However, the plea did not receive the level of attention regarding the issue of declining semen quality and other markers of male reproductive health that Levine had previously anticipated in his studies.
Microplastics
Plastic is the most prevalent type of marine debris found in our ocean and Great Lakes. Plastic debris can come in all shapes and sizes, but those that are less than five millimeters in length (or about the size of a sesame seed) are called ‘microplastics’.
