The invisible daily cocktail that is making us sick

The alarm clock rings. You go through the shower and smear yourself with, at the very least, 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 new polyester shirt, nice and cool. You leave the house and grab a takeaway coffee and a tray of cut fruit. You walk to work along a street with heavy traffic and quite a lot of noise.

It's 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 harmful 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 fertility problems. And there are starting 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 be harmful,” she concludes.

Omnipresent

Trying to eradicate endocrine disruptors from our daily life is 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," the researcher admits.

One of the places where they are found in "extremely high concentrations" is in thermal labels on food. "When you buy a tray of fish, meat, a slice of cheese, or a cucumber wrapped in plastic at the supermarket that has a price label on it, compounds with hormonal disruptive activity pass in high amounts 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 accumulate. “For many years we have studied one contaminant at a time, and this is not 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 fellow IDAEA-CSIC researcher 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 necessarily imply that everyone will 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 caused by these toxins is greater. Pregnancy, early childhood, and puberty are the periods when the hormonal system directs the development of organs, and any interference can have lasting consequences. This also likely applies to women during menopause, although there is little information available at the moment.

“A fetus is forming all of 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 precisely 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 which aims to investigate how endocrine disruptors influence the health of pregnant women and children. The ultimate 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 Germans Trias i Pujol (Badalona) and Arnau de Vilanova (Lleida) hospitals, is the lead researcher for the puberty section. “The damage that these compounds produce in children's hormonal systems can cause early puberty,” she warns, and adds: “Early puberties have health impacts; they have been associated with a higher risk of obesity, diabetes, and even stunted growth in children.” “We can prevent these future diseases,” she adds, “by trying to reduce 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 brain of fetuses and babies.

Thirty years of evidence and regulation that always arrives late

But if the scientific community has been warning about the risks of some endocrine disruptors for decades, why do they still remain 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 of 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 prohibited its use in materials in contact with food, and the industry still has a transitional 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 goods, 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 prohibition,” emphasizes Gago.

During this time, however, health authorities have also been radically revising their perception of risk. In 2023, the European Food Safety Authority (EFSA) reduced the tolerable daily intake of bisphenol A 20,000-fold. “It is a huge reduction, nonsense,” exclaims this researcher from IDAEA-CSIC. “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 almost identical one,” she states. “If a family of compounds shares chemical structure and mechanisms of action, the regulation should be joint,” she demands.

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 chemicals 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 one-off 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 what weight 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 such as 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 every person to have 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”.