The invisible daily cocktail that is making us sick

The alarm clock rings. You go through the shower and smear yourself, at the very least, with about seven cosmetic and personal hygiene products, including creams, soaps, deodorants –if you are a woman, the number rises to nine–, according to data from Cosmetics Europe. You wear a polyester shirt for the first time, nice and cool. You leave the house and grab a coffee to go and a tray of cut fruit. You walk to work along a street with heavy traffic and quite a bit of noise.

It is not even nine in the morning yet and you have already been in contact with dozens and dozens of chemical compounds. Most, surely, will be harmless, but some will belong to a family of substances that has worried scientists for decades because of the detrimental impact they have on human health: endocrine disruptors.

These compounds come mainly from petroleum derivatives and are capable of deceiving the body, because they mimic the functioning of natural hormones, which are the molecules responsible for communication between cells, tissues, and organs. They also block cellular hormonal receptors and alter the functioning of the entire endocrine system.

There is solid scientific evidence linking prolonged exposure to these environmental toxins with some of the most prevalent non-infectious diseases in society, such as obesity and diabetes, as well as with infertility problems. And there are beginning to be indications that they could influence the development of some types of hormone-dependent cancers, such as prostate or breast cancer.

“The concept of endocrine disruptor has existed for decades, but we are identifying more and more everyday chemical products with this capacity,” explains Martine Vrijheid, a researcher at the Barcelona Institute for Global Health (ISGlobal). “We are exposed to them every day in very low doses. The question is knowing when they really start to be dangerous, because unfortunately it is still difficult to know at what level these exposures can result in being harmful,” she concludes.

Omnipresent

Trying to eradicate endocrine disruptors from our day-to-day life is a mission impossible, because they are everywhere: from plastics to cosmetics, including pesticides, food packaging, ultra-processed food, household cleaning products, toys, clothing, and furniture. To make matters worse, many do not even appear identified on product labels. "It is very complicated to avoid them completely," admits the researcher.

One of the places where they are found in "very high concentrations" is in thermal labels on food. "When you buy a tray of fish, meat, a piece of cheese, or a cucumber wrapped in plastic at the supermarket that has a price label on it, compounds with hormonal disrupting activity in high quantities pass from these labels to the food," warns Pablo Gago, a researcher at the Institute of Environmental Assessment and Water Research (IDAEA-CSIC). But even the fact that food is in contact with plastic "is not safe, because there is very clear evidence that these chemicals are transferred," he adds.

In fact, scientific studies conducted with large population samples have shown that 95% of people have traces of these harmful chemicals in our bodies, which penetrate the body through skin contact, ingestion, or inhalation. So far, more than 1,000 have been identified, some of which are very persistent, such as certain pesticides that can remain in the body for up to 10 years; others, such as parabens or bisphenols, on the other hand, are excreted through urine in a matter of hours.

In general, the majority of the levels of these endocrine disruptors in the products we consume are very low. For this very reason, their sale is permitted. The problem, however, is that some of them accumulate. “For many years we have studied one contaminant at a time, and that is not the reality,” explains Gago, because – this scientist argues – “it is not a single chemical compound that will make you sick, but the sum of prolonged exposures to multiple factors”.

“There is a false conception that the dose makes the poison,” warns the fellow researcher from IDAEA-CSIC Montse Marquès, who points out that the fact that they do not have an immediate effect complicates society's perception of risk. It must be added that being exposed to them does not imply that everyone will necessarily get sick, because individual sensitivity also plays an important role. “Studies on large populations show that people who are more exposed for longer periods have a higher risk of developing certain diseases, but this does not mean that a specific person with a certain level of bisphenol A will end up suffering from diabetes,” Marquès clarifies.

The first years of life, a critical window

Researchers agree that there are particularly sensitive stages in which the harm from these toxins is greater. Pregnancy, early childhood, and peripuberty are the periods when the hormonal system directs the development of organs and any interference can have lasting consequences. This is also likely true for women during menopause, although there is currently little information.

“A fetus is forming all its organs at an extraordinary speed,” explains Martine Vrijheid, director of the Environment and Health over the Life Course program at ISGlobal. In this program, they are specifically focused on studying the impact of exposures during these vulnerable periods. “If something alters the process of formation and maturation of the child’s organs and tissues, the effects can manifest many years later,” she points out.

In this sense, Catalonia is leading an international project called Hypiend that aims to investigate how endocrine disruptors influence the health of pregnant women and children. The final goal is to generate knowledge to be able to make science-based recommendations to reduce the population's exposure and thus improve their health.

Paula Sol Ventura, a pediatric endocrinologist and coordinator of the Environmental Health Unit at the Arnau de Vilanova University Hospital (Lleida), is a principal investigator at the Germans Trias i Pujol Research Institute (IGTP) for the puberty component. “Exposure to certain compounds that interfere with the hormonal system during childhood has been associated with an earlier onset of some pubertal signs,” she warns, adding: “When puberty begins too early, it can affect growth and compromise final height. It has also been associated with a higher risk of metabolic problems and, in some children, can have an emotional or social impact. We can help contribute to protecting future health—she adds—by trying to decrease exposure to these substances,” which is exactly what Hypiend pursues.

Another project that seeks to better understand the impact of these compounds in vulnerable stages is the one led by Montse Marquès, from IDAEA-CSIC, which follows pregnant women and their babies at the Joan XXIII Hospital in Tarragona. They collect different biological samples, as well as clinical and sociodemographic data, lifestyle, diet, and evaluate the associations between these exposures during gestation. “We are taking a first step to understand how these harmful chemical substances are distributed through the body and enter the placenta,” says Marquès, who recalls that there are already studies done with animal models that have shown that these toxins can cross the blood-brain barrier and penetrate the brains of fetuses and babies.

Thirty years of evidence and a regulation that is always late

But if the scientific community has been warning about the risks of some endocrine disruptors for decades, why are they still present in so many consumer products? For researchers, bisphenol A is probably the best example of the distance that separates scientific knowledge from regulation. This compound, used for years to manufacture rigid and transparent plastics, interior coatings for cans and other food packaging, was considered safe because it had passed classic toxicological studies. But at the end of the nineties, the first evidence began to appear that it could act as an endocrine disruptor.

“Since then, epidemiological studies have done nothing but confirm those initial suspicions,” explains Pablo Gago, from IDAEA-CSIC. However, it was not until the end of 2024 that the European Union banned its use in materials in contact with food, and the industry still has a transition period to adapt to it. Even so, the EU regulation established that as of this month of July, containers, wrappers, and coatings, such as those for canned food, containing this substance should have stopped being sold in European countries. “We are talking about almost thirty years between the first evidence and the effective ban,” stresses Gago.

During this time, however, health authorities have also been radically revising the perception of risk. In 2023, the European Food Safety Authority (EFSA) reduced the tolerable daily intake of bisphenol A by 20,000 times. “It is a huge reduction, a nonsense,” exclaims this IDAEA-CSIC researcher. “It means that what was previously considered safe, we now know is not safe at all, because reducing its presence 20,000 times is almost eliminating it,” he concludes.

However, the disappearance of bisphenol A does not necessarily solve the problem. Many companies have replaced it with other compounds from the same family, such as bisphenol S or bisphenol F. “Products are marketed with the ‘BPA-free’ label, but that does not mean they do not contain endocrine disruptors,” warns the researcher, for whom it is a matter of misleading marketing.

For Martine Vrijheid, “it makes no sense to ban a chemical product every ten years while the industry immediately replaces it with another that is almost identical,” she states. “If a family of compounds shares a chemical structure and mechanisms of action, the regulation should be joint,” she claims.

This gap between scientific evidence and prohibition is a consequence of the fact that, unlike medicines, which must demonstrate their safety before reaching the market, many industrial chemical products began to be used under the opposite principle: they were considered safe as long as it was not proven that they could be dangerous. “Today there are hundreds of thousands of chemical substances on the market and evaluating them one by one is practically impossible,” recalls Gago.

It is also complicated to prove that a substance causes a specific disease, because no one develops diabetes, infertility, or cancer after a single contact with a chemical compound. The effects are chronic, they can take decades to manifest, and they coexist with many other factors, such as diet, smoking, genetics, or physical activity.

“By working with large cohorts we can approximate this effect,” considers Montse Marquès, from IDAEA-CSIC. “We measure the levels of contaminants, but also many other variables, such as body mass index, socioeconomic level, or lifestyle habits. With statistical tools we can isolate the weight that each exposure to each factor has,” she adds.

The debate, in the courts

The debate, however, is no longer just scientific. It is also political, economic, and judicial. Last July, New York Attorney General Letitia James sued companies like 3M and DuPont, accusing them of having hidden the risks of PFAS, the so-called “forever chemicals,” for decades. The lawsuit maintains that the companies continued to manufacture and market these compounds despite knowing the possible effects they had on health and the environment.

PFAS have been used for years because they repel water and grease. They are found in non-stick pans, food packaging, firefighting foams, waterproof clothing, or some cosmetics. The problem is that they practically do not degrade, and they accumulate in the environment, in animals, and also in the human body. Several studies have linked them to an increased risk of cancer, metabolic disorders, infertility, or developmental problems.

But, then, what can we do? Researchers reject that all responsibility should fall on consumers. “People need information, but we cannot expect that every person has to go around interpreting product labels to protect their health. The best way to reduce exposure is for these compounds to stop being part of consumer products,” concludes Vrijheid.

“Responsibility cannot fall exclusively on the individual,” consider Gago and Marquès. “When a person enters a supermarket, they should be able to take for granted that everything they buy is safe.”