What are the impacts of pollution on fertility?

You can't have missed it: environmental pollution is reaching alarming levels today. We know its consequences for the planet and human health. But science is increasingly focusing on the link between pollution and fertility. Does our ecosystem directly impact our ability to conceive? Let's zoom in on this issue, its alarming truths, and our tips to best protect your fertility.

A quick reminder about gametes: the basic unit of reproduction

The exact link between fertility and pollution remains quite abstract. Scientists are beginning to seriously investigate the topic, but they still have much to discover. However, here's what we already know.

Impacts of air pollution on fertility

According to a study published on Cairn, there is an increasing trend towards a grim observation: pollution impacts our ability to conceive children [1]. The cause? Organic pollutants (hydrocarbons, found for example in smoke), atmospheric pollutants, and metallic pollutants (such as copper, lead).

The problem with these chemical substances is that they negatively influence our hormones and can damage reproductive cells in both women and men. As a result, male gametes are damaged, and egg production is disrupted. These pollutants can also cause stress to these same cells and, consequently, create damage to sperm DNA and affect future generations.

This article may also interest you: How to know if you are fertile (men)?

Harmful effects of pollution on gametes

Science can therefore already confirm: in our reproductive health system, the first victims of pollution... are gametes.

According to Santé publique France, pollutants can generate several problems for human fertility [2]. In men, this can manifest as:

• a decrease in sperm motility;
• a loss of quality;
• congenital diseases.

Female fertility is also impacted, notably with:

• an increased prevalence of endometriosis and ovarian insufficiency;
• an increase in recurrent miscarriages;
• a disruption of the menstrual cycle.

In both sexes, there can also be a decrease in sperm and egg production, and/or premature puberty, as well as a higher risk of developing a chronic illness in adulthood.

The consequences of pollution on fertility worldwide

Across the globe, we are starting to notice how detrimental the consequences of pollution on fertility are.

China: an alarming case study

China, in particular, presents a worrying situation. A recent study published in JAMA (Journal of the American Medical Association) explains that researchers analyzed the gametes of over 33,000 Chinese men [3]. Their finding? Air pollutants diminished the ability of sperm to move correctly. As a result, the overall decrease in sperm quality would be more caused by environmental factors than genetic ones.

The rest of the world: worrying trends

Although China is one of the most polluting industrialized countries on the planet, it is obviously not the only one concerned by the issue. In an investigation into male fertility, GQ magazine highlights an alarming fact: boys produce half as much sperm as their grandfathers. This observation is based, among other things, on a cross-analysis of several studies that revealed a drop of more than 50% in sperm concentration in less than 40 years (1973-2011) in Western men, with no sign of slowing down in the most recent years of the period studied [4].

A literature review on male health also estimates that the male factor is responsible for approximately 50% of couple subfertility cases according to WHO data [5].

Until what age is a man fertile? We tell you everything!

The culprits: toxic components and their effects

So, who are the culprits behind such a drop in fertility? Well, there are many on the accused bench. Here are a few.

Endocrine disruptors: invisible enemies

Endocrine disruptors are chemicals that interfere with our hormones and weaken fertility. These include:

• bisphenols;
• dioxins;
• paracetamol;
• phthalates.

The problem is that they occupy a significant place in our daily lives: food packaging, cosmetic products, toys... How do they work? It's simple: they mimic (or block) natural hormonal actions, and consequently lead to reproductive health disorders.

Also beware of the "cocktail effect," which is simultaneous exposure to several chemicals: in these cases, the negative impact is amplified. It is recommended to prioritize products designed without endocrine disruptors, especially for cosmetics and hygiene products.

Other pollutants and their potential impacts

Other culprits for declining fertility? Fine particles (present in air pollution), pesticides (numerous in agro-food), and heavy metals. All these molecules also have consequences for our reproductive health, as they affect the quality of gametes.

Microplastics and PFAS: newly identified threats

In recent years, two new families of pollutants have been receiving increasing attention from reproductive health researchers.

Microplastics, found even in reproductive organs

After the brain, placenta, and blood, microplastics have been detected directly in human testes, with a measured association between their presence and a decrease in sperm count [6]. A study conducted across several sites in China (113 men) has also established a link between the presence of microplastics in semen and sperm dysfunction [7].

More recently, Italian researchers detected microplastics for the first time in ovarian follicular fluid, the fluid surrounding the developing oocyte, in 14 of 18 women undergoing IVF treatment in Salerno, with an average concentration of 2,191 particles per milliliter [8].

PFAS ("forever chemicals"), exposure starting in utero

PFAS (per- and polyfluoroalkyl substances) are nicknamed "forever chemicals" because they practically do not degrade in the environment or in the body. They are found notably in food packaging, non-stick pans, waterproof clothing, or certain cosmetics.

A benchmark Danish study, conducted on 864 young men, showed that their mothers' combined exposure to seven different PFAS during the first trimester of pregnancy was associated, in these men as adults, with a lower sperm concentration and a higher proportion of immotile sperm [9]. This study is the first to examine combined exposure to more than two PFAS during this specific period of development, which corresponds to the formation of the testes in the fetus.

Simple measures to adopt

We conclude this article on a more optimistic note. To protect yourself (as much as possible) from pollution and safeguard your fertility, you can implement a few simple actions:

• Prioritize walking or cycling. You'll do good for your body and the planet.
• Choose ecological cosmetics and cleaning products to reduce your exposure to endocrine disruptors.
• Ventilate your home to decrease the concentration of indoor pollutants.
• Filter your tap water to limit any potentially present heavy metals.
• Reduce your use of plastic, which often carries chemicals — prefer glass or stainless steel instead.
• Try to eat organic and local if you can: foods less exposed to pesticides, and less polluting agriculture.
• Adopt a healthy lifestyle and limit your alcohol consumption. There is a real link between liver and fertility, so take care of it.

Yes, we agree: these actions may seem anecdotal compared to the environmental challenges we face. But their cumulative effect can truly make a difference and help you preserve your reproductive health at the same time.

The impact of pollution on our global health, female and male infertility, remains a huge problem. But recognizing it also highlights our collective ability to positively influence the future. So let's continue to inform ourselves and adopt simple, yet responsible behaviors. A virtuous cycle for your health and that of the planet.

Frequently Asked Questions about pollution and fertility

Does pollution really affect fertility?
Yes, several studies converge: endocrine disruptors, air pollution, and heavy metals are associated with a degradation of fertility, in both men and women [2].

What are the main endocrine disruptors to avoid?
Bisphenols, phthalates, dioxins, and parabens are among the most studied. They are found in food packaging, cosmetics, and toys.

Has sperm quality really declined over the decades?
Yes: an analysis spanning several decades measured a drop of more than 50% in sperm concentration in Western men between 1973 and 2011 [4].

Can pollution cause recurrent miscarriages?
High concentrations of bisphenol A or phthalates have been observed in the blood of women suffering from recurrent miscarriages, endometriosis, or ovarian insufficiency, although a strict causal link has not yet been established [2].

How can one reduce exposure to pollutants in daily life?
Prioritizing cosmetics without endocrine disruptors, reducing plastic use, ventilating one's home, filtering tap water, and eating organic/local are simple actions that, cumulatively, help limit exposure.

Do microplastics and PFAS really affect fertility?
These are recent but well-documented areas of research: microplastics have been found in human testes and ovarian follicular fluid, and a Danish study showed that prenatal exposure to PFAS was associated with poorer sperm quality in adulthood [6,8,9].

This article is for informational purposes only and does not constitute medical advice. If you have any doubts about your fertility, consult your doctor or a specialist.