We are exposed to many different synthetic endocrine disrupting chemicals (EDCs) via food, water, indoor air and dust, and consumer products. We know this from studies that measure chemicals in our bodies and rivers, drinking water and air.

Hazardous chemicals are now ubiquitous in air, water and soil and food according to a 2019 report from the United Nations. That report also found that endocrine disruptors are common in the human population.

Health concerns and EDCs

At the same time we are seeing an alarming increase in hormone-related diseases in people.

Health concerns related to EDCs include:

• Fertility problems
• Birth defects of the genitals
• Hormone-related cancers – such as breast, testicular, and prostate cancer
• Impaired brain development
• Obesity and diabetes.

Numerous laboratory studies and epidemiological trends have strengthened concerns that the rise in the incidence of reproductive problems, hormone-related cancers and other metabolic diseases is partly linked to exposure to EDCs. There are also mounting concerns about impacts on wildlife.

Leading scientists around the world – for example, from the international Endocrine Society – have repeatedly raised the alarm and called on decision makers to take more effective steps to reduce exposure to EDCs. For several years the European parliament and member states have put pressure on the European Commission to act on EDCs.

Until now, however, the EU Commission has failed to properly protect human health and the environment from exposure to endocrine disruptors.

Find out what CHEM Trust is doing to bring pressure to bear on decision-makers. Find out how to reduce your risks from EDCs.

Check out our briefing on how women are disproportionately exposed to harmful chemicals.

If you want to know more about the health risks, read on.

Endocrine disruptors, fertility problems and male genital defects

It now appears that in several European countries around 1 in 5 young men have impaired fertility. Men’s exposure to endocrine disrupting chemicals has been linked to this problem. Studies of male animals have shown that chemicals, such as certain phthalates, that block the male hormone testosterone, may cause birth defects to the penis and testicles, and low sperm counts. Humans are also exposed to these chemicals. So it’s likely that they play a role in birth defects among baby boys, declining sperm counts in young men, and testicular cancer.

These disorders affect a surprisingly large number of men and boys. It is difficult to prove or disprove whether these chemicals are actually causing the de-masculinising effects. But evidence is mounting on the action of endocrine- or hormone-disrupting chemicals that can block testosterone.

Genetic, lifestyle and environmental factors may each play a part. But the increase in testicular cancer over the past 40 years is such that lifestyle or something in the environment must be largely to blame, because genes in a population do not change within such a short time.

This hypothesis is the cause of much concern within the medical community and has been written about extensively in respected journals such as The British Medical Journal and The Lancet.

Want to know more? Check out CHEM Trust’s publications summarising the state of the science on male reproductive health.

Endocrine disruptors and trends in reproductive disorders

Incidences of reproductive disorders, including testicular cancer, are showing a worrying increase. The seriousness of the reproductive health problem among males is highlighted by recent health statistics:

• In many industrial countries, testicular cancer is now around twice as common as it was 30-40 years ago.
• A major review of research, carried out in 2017, found an estimated 50-60% drop in sperm count in developed nations since 1973. A further study in 2022 suggests this is an ongoing issue
• 1 in 5 young men in several EU countries have sperm counts so low that they are sub-fertile and may have difficulty getting their partners pregnant.

Several studies have shown associations between pre- or post-natal exposure to certain pesticides or phthalates and effects on reproductive disorders or male hormones.

Hormone-induced cancers

Breast cancer

Around 1 in 8 women in Europe (including the UK) now gets breast cancer, a higher rate than 20 years ago.

The increase is not just down to people living longer or having children later, inherited genetic risk or higher reporting of breast cancer. The vast majority of women who develop the illness do so because of environmental factors.

There is good reason to suspect that hormone disruptors that mimic the natural female hormone, oestrogen, are playing a role in the increase in breast cancer. A woman’s lifetime exposure to oestrogen is known to influence her risk of breast cancer.

Hormonally active chemicals are all around us. They include the classic nasties such as PCBs and DDT. Some of those were banned years ago but they persist in our bodies and the environment.

Other EDCs are still unregulated and are found in food, water and the air we breathe. They are common in personal care products, plastics, electronic goods, beds, sofas, curtains and cushions.

For instance, the hormone disrupting chemical bisphenol A (BPA) is still found in food and drink containers.

BPA can directly affect the mammary gland at low doses and significantly increase ductal growth and thereby increase the risk of developing breast cancer. Scientists have discovered that a foetus can be exposed even before birth. BPA can be transmitted from mothers to children in the womb and even through breastfeeding.

The EU has officially listed BPA as an endocrine disruptor for human health and the environment.

BPA has recently been banned in thermal paper till receipts after lots of pressure from CHEM Trust and other organisations.

Read more about what CHEM Trust is doing to protect consumers, and how to avoid BPA and other bisphenols.

Breast Cancer UK has further information on breast cancer and harmful chemicals in their new Prevention Hub.

Endocrine disruptors and other cancers

EDCs may re-programme stem and progenitor cells, potentially transmitting a lifelong predisposition to a disease such as prostate or testicular cancer in men. Even low levels of BPA exposure may increase the risk of prostate cancer.

Exposure to endocrine disruptors is also linked to uterine and ovarian cancer in women.

Endocrine disruptors and children’s brain development

It is well established that some chemicals can affect normal brain development. Chemical exposure is now so ubiquitous that babies are born already polluted by a cocktail of chemicals. This means that children may not reach their full potential.

Brains are astoundingly complex. They are made up of more than 85 billion neurons which grow, develop and interconnect during our lives. Brains take a long time to mature and it isn’t until our 20s that the neurons in the brain are fully developed.

Hormones play an important role in brain development and function. But their normal function can be disrupted by chemicals that, for example, mimic or block a hormone. Exposure to some chemicals may affect the action of thyroid hormone, which is essential for growth and brain development. A child’s brain only gets one chance to develop, so an early impact can cause problems for the rest of an individual’s life.

Scientists are increasingly linking an upsurge in behavioural challenges to chemical exposure during development. These behavioural traits include Attention Deficit Hyperactivity Disorder (ADHD), impaired social interactions; and intellectual challenges include learning disabilities, impaired reasoning skills (reduced IQ) and autism. The effects may be subtle at the individual level, but across a population they can represent a significant decrease in intellectual ability within a generation, which may have big societal costs.

Lead and other toxins

Historically, the brain harming properties of lead, mercury and PCBs were spotted only when the damage to many children had already been done. Testing of these chemicals before they were in common use had been inadequate, so there was widespread exposure and harm to the population at large.

Lead is well known to harm people. But new evidence shows associations between levels of lead in blood and ADHD, inattention and hyperactivity. Although lead is now banned in petrol it can still be found in old paints and old water pipes. Such ongoing low-level exposure continues to damage the future of millions of children, who may never reach their full intellectual potential.

In fact, very few chemicals have ever been tested for their ability to de-rail brain development. Current test methods are inadequate, costly and time consuming, so there is a need for better ways to identify chemicals with developmental neurotoxic properties.

Read more about the impact of chemicals on brain development in our factsheet (pdf).

Endocrine disruptors, obesity and diabetes

It is a common view that obesity is all to do with consuming too many calories and doing too little exercise, plus a genetic predisposition in some individuals. But a new line of research suggests that exposure to certain synthetic chemicals in our environment can also play an important role in obesity.

And while obesity can increase an individual’s risk of developing diabetes, growing evidence also points the finger at a link between exposure to EDCs and diabetes.

Chemicals implicated in causing weight gain and/or diabetes include many found in everyday products in our homes such as:

• Bisphenol A – found in food packaging.
• Flame retardants – found in carpets and sofas.
• Phthalates – found in food packaging.
• PFAS chemicals – found in some food packaging, clothing and non-stick cookware.

A link between the levels of contaminants in people’s bodies and increased risk of diabetes comes from several studies of the population at large. Tests on bodily fluids show that most of us are exposed to dozens of chemicals, some of which our bodies cannot easily get rid of. These chemicals may disrupt our hormone systems and metabolism.

Endocrine disruptors and public health

The increase in obesity and diabetes is of great public concern worldwide, not just because of its effect on individuals’ quality of life, but because of its economic toll.

• 29% of adults were classed as obese in England in 2019
• 20% of children aged 10-11 were classed as obese in England in 2019.
• 4.7 million people in the UK (about 7% of the 2018 population) have diabetes. The number of people diagnosed with diabetes doubled from 1998 to 2018.
• According to the World Health Organisation the number of people with diabetes globally has risen from 108 million in 1980 to 422 million in 2014.