We live surrounded by toxins. Thus, many of the 12,000 chemical substances used in the global production of materials that come into contact with food (8,000 in Europe) have not undergone adequate tests to determine their real toxicity, as reported at the time by the Alliance for Health and the Environment (HEAL).
Exposure to these chemicals and others present in objects that we use in our daily lives represents a significant risk to reproductive health, affecting fertility, fetal development and hormonal health in both men and women.
A pioneering methodology developed by the Institute of Environmental Diagnosis and Water Studies (Idaea) of the Higher Council for Scientific Research (CSIC), in collaboration with the French National Institute for Agronomic and Environmental Research (INRAE) and the Rovira i Virgili University (URV) of Tarragona, has identified 42 chemical compounds of daily use in human semen.
The results, published in the journal “Exposome”, provide a detailed view of global exposure to toxic compounds and their possible impact on male reproductive health.
Infertility affects 15% of the world’s populationa problem that has worsened in recent decades, with male factors being responsible for 40-50% of infertility cases.
Environmental exposures and exposures derived from current lifestyle are postulated as the origin of reproductive health problems. “Although our study does not allow us to establish causal relationships between the presence of multiple chemical substances and spermatogenesis, it does show associations between exposure to these compounds and semen quality,” explains Montse Marquès, IDAEA-CSIC researcher and lead author of the study, in a statement.
To evaluate its impact, the new study evaluates the chemical exposome, the set of chemical substances to which the population is exposed, using an innovative high-resolution mass spectrometry methodology. This technique determines the exact mass of compounds with a precision greater than 0.001 atomic mass units, which allows us to distinguish between substances that, although they appear the same, have different chemical compositions.
To determine the presence of chemical compounds, the research analyzed semen, blood and urine samples from a study group made up of 48 healthy men between 18 and 40 years old, residents in Tarragona.
The research team applied broad-spectrum chemical screening to analyze the set of chemicals to which the participants were regularly exposed.
After To track the presence of more than 2,000 organic compounds, the technique allowed the detection of 42 substances in semen, 42 in urine and 48 in blood. The substances belonged to complex mixtures that included artificial sweeteners, insecticides, perfluoroalkyl and polyfluoroalkyl substances (PFAS), flame retardants, food-related compounds, drugs and markers of tobacco use.
In the case of PFAS, they are one of the families of chemicals most used by the industry today. They are present in a multitude of everyday objects, from a frying pan to makeup products. In fact, in 2018 it was estimated that there were more than 4,700 different substances on the market used in sectors as diverse as food processing, the textile industry or the manufacturing of medical supplies. Recently the European Commission has banned the use of these chemicals in food packaging, cosmetics and textiles due to their health risk, including PFAS present in pizza boxes.
“Traditionally, studies focus on specific families of toxic compounds. In this work, thanks to high-resolution mass spectrometry, we have applied a screening capable of tracking thousands of compounds at a time in three different biological matrices: semen, blood and urine,” explains Marquès.
Sperm quality
The analysis showed that some of the toxic compounds detected negatively altered different parameters of semen quality. For example, acesulfame (a widely used artificial sweetener), bisphenol-S (a compound used in plastics and resins), the insecticide nitenpyram or certain surfactants for industrial and pharmaceutical use, are were negatively associated with the total number of sperm, their shape and concentration.
The flame retardant triethyl phosphate (used as a flame retardant in construction materials, vehicles or electronics) was linked to a lower sperm volume, while another additive used in tire manufacturing was linked to a reduction in mobility and vitality.
The study also confirmed negative associations already described in the scientific literature for compounds derived from tobacco, such as nicotine and cotinine, and for persistent perfluorinated substances, used in kitchen utensils, packaging and clothing, among others. The results reinforce the evidence that the chemical exposome can influence the formation and development of sperm (spermatogenesis) and contribute to the decline in male fertility observed in recent decades.
“We have verified that seminal plasma is a matrix of great interest to study the chemical exposome in relation to semen quality, since it allows us to identify mixtures of contaminants that may go unnoticed in blood or urine, but that are closely linked to reproductive function,” declares German Cano-Sancho, researcher at the INRAE Laberca Unit and first author of the study.
This approach allows us to optimize the use of biological samples and obtain a much more complete picture of the real exposures of the general population, opening new avenues for research in environmental and reproductive health.
And it is urgent. It should be remembered that previous studies have shown that, for example, the feces of babies contain, on average, PET concentrations 10 times higher than those of adults, as demonstrated by research published in “Environmental Science & Technology Letters”. Or that pregnant women exposed to PFAS are at greater risk of obesity and heart disease 20 years later, according to a study published in “The Journal of Clinical Endocrinology & Metabolism.”
And although these chemical substances are valued for their waterproof, heat-resistant and non-stick properties, these substances, in many cases, endocrine disruptors can interfere with hormones and cause health problems such as cancer, infertility, developmental problems in children, obesity… And the truth is that we live surrounded. In Europe, too. Thus, an analysis carried out on 24 senior political officials from 19 European Union countries revealed at the end of 2025 that more than half of them have concentrations of PFAS in their blood that could pose health risks, as reported by Hogar Sin Tóxicos.