Semen also has geography. And in Spain, Madrid does not fare well. Let’s assume that semen quality has been declining for decades. In Spain it has fallen 28% in just 15 years, a 78% if we value the last two decades. That is to say, a concentration of sperm is produced so low that it is less than half of what it was in the 70s. And it continues in constant regression. With this breeding ground, the question is: and which region is coping best with this decline?
Alcohol and coffee have nothing to do with each other. The investigation analyzed 386 men seen in seven Spanish fertility clinics—such as the Bernabeu Institute—between 2024 and 2025. After adjusting variables such as body mass index, exercise, and alcohol, tobacco, or coffee consumption, the authors observed that men from the north recorded the best seminal parameters, even when their habits were similar to those of other regions. This gives us a clue to talk about pollution, environmental inequality and public health.
The results have been presented at the 42nd congress of the European Society of Human Reproduction and Embryology (ESHRE). AND In it we can find clear differences in semen quality depending on the area in which the donors live. Those who win this game are the residents of the north, with Asturias and Cantabria far ahead of Madrid and the center of the peninsula. But there is fine print.
More agile, faster. The total count of motile sperm is striking, almost double in the north than in the central area. In data: 94.35 million on average compared to 50.11 million in the central area. This index talk about health: “the northern region also presented the highest average sperm concentration (80.96 million/ml) and sperm motility (44.79%), compared to 55.4% in southern Spain and 53.4% in the center.”
If diet, exercise or substance use alone do not draw this map of semen quality, what does? The first conjectures point to a population that breathes worse, drinks and involuntarily incorporates into its body part of the atmospheric pollution, a mixture of industrial and agricultural toxins, where endocrine disruptors in plasticspesticides and everyday cosmetics.
Out of the pot. Beyond Spain, the pattern repeats itself: studies with fertile men In cities such as Copenhagen, Paris, Edinburgh and Turku, they already showed in the early 2000s that the Finns had the highest sperm concentrations while the Danes recorded the lowest values, with also variations in mobility depending on the city.
If we take a look at the retrospective analyzes of French donors found significant differences within the country itself in volume, concentration, and total number of sperm. The north wins again. In general, the men of the nordic west They have worse semen quality than those from the Baltic area, in parallel with a higher incidence of testicular cancer, another marker of male reproductive stress.
Does better semen equal more pregnancies? Not necessarily, but almost. Let us keep in mind that, although the relationship with fertility is not linear, below certain thresholds of concentration and mobility, the probability of spontaneous pregnancy decreases considerably.
To understand what “better semen” means, it is worth going down a level. According to the World Health Organization, reference values are measured in concentration (millions of sperm per milliliter), ejaculate volume, percentage of motile sperm and proportion of sperm with morphology considered normal. It is necessary to distinguish between progressive sperm (the vanguard that advances efficiently), versus non-progressive and completely immotile ones. In morphology, the shape of the head, middle piece and tail (flagellum) is evaluated, since anatomical alterations can make fertilization difficult.
Plastics and fertility. By the way: nitrile and latex gloves release plastic microparticles and contaminate environmental measurements does not invalidate that the presence of endocrine disruptors in human tissue does not affect male fertility. The evidence is solid. For example, a 2023 study that analyzed 6 human testicles and 30 semen samples found microplastics both in tissue and fluid: around 0.23 ± 0.45 particles per milliliter in semen and 11.60 ± 15.52 particles per gram of testicle, with sizes mostly between 20 and 100 microns, finding polystyrene in testicles and polyethylene and PVC in semen.
The problem is broader. The taboo of male fertility, treated as a private matter, has obscured problems that can be investigated as a collective indicator. And this deterioration does not respond, or not only, to individual behavior. The greatest weight lies in the place you livenot in the genes you carry. A cardinal clue: of course smoking, drinking or moving more or less matter, but it does not depend so much on personal decisions. A debate that is more political than folkloric (and health and regulatory).
A cocktail of bisphenol A, methyl, ethyl, propyl and butylparabens, benzophenones and phthalate metabolites is directly associated with significant reductions in total and progressive sperm motility. Therefore, Asturias beating Madrid is not something to celebrate, but rather to raise the alarm about the qualities of the water – it will not be that good -, what pesticides are used nearby and what mix of chemicals goes through daily life. The tip of an iceberg that does not lie in who comes out better off, but rather in the cost of those who come out worse off.
Images | Unsplash (1, 2 and 3)
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