Are EDCs a major global health hazard?

Are EDCs a major global health hazard? Jessica McCallin discusses the evidence

Men becoming women, women becoming men, the birthrate for baby boys plummeting..... it sounds like the kind of sensational scare-mongering which usually turns out to be science fiction rather than science fact. But research is increasingly finding that something strange is happening to the human body. Our hormonal systems do not seem to be functioning the way they used to. The finger of blame is being increasingly pointed at a raft of chemicals. Of the estimated 30,000 man-made chemicals currently produced, six endocrine disrupting chemicals (EDCs), also known as hormone disrupting chemicals, or hormone and oestrogenic mimicking chemicals, are causing particular concern. Scientists and environmental think tanks have linked them to birth defects, cancer, damage to vital organs, allergies and asthma. The hormonal system controls many crucial aspects of the working of the body, such as the development of sexual characteristics and of the brain. Many of the chemicals which are thought to affect it were not developed 100 years ago. The recent increase in a whole range of hormone associated illnesses and conditions has been linked to their presence all around us today. EDCs are problematic, not just because they cause problems in one-off doses, but because they are persistent. They do not break down, but accumulate in the body's fatty tissue. A spokesperson for Friends of the Earth's Safer Chemicals Campaign says, "The current regulatory system for EDCs is a failure and protects neither our health nor the health of the environment. The chemical industry claims that it is extremely heavily regulated. In fact, only 14% of the highest production volume chemicals in Europe have got a basic set of safety data publicly available. The current regulatory system does not require safety data to be produced on chemicals which have been on the market since before 1981, which is the majority of chemicals."The chemicals industry has not bothered to gather this data over the decades these chemicals have been on the market. In addition, we continue to be exposed to chemicals that accumulate in our bodies and environment, and to hormone disrupting chemicals."The European Union (EU) is currently reviewing chemicals regulation, with significant pressure from Scandinavian countries to clean up the system. However, the chemical industry, a £250bn industry in the EU, is fighting for the status quo. In the US, the Environmental Protection Agency is screening thousands of chemicals for endocrine disrupting effects, but to date there is no sign of any new controls on existing chemicals, even on the alkyphenols which are being phased out in Europe. International regulations restricting the use of persistent organic pollutants cover some, but not all, EDCs. According to campaigners, they don't go far enough. The Organisation for Economic Cooperation and Development has a programme for EDCs, but it focuses mainly on the development of testing procedures, not on phasing out their use. In short, not very much is being done to actually stop the use of the main culprits. While individual EDCs are problematic enough, evidence is growing that as cocktails of chemicals, they are even more dangerous. Worryingly, attempts to develop regulatory oversight of chemicals are ignoring chemical mixtures, focusing on individual chemicals in isolation. Scientists are also beginning to understand that timing is crucial and that EDCs are particularly harmful to babies in the womb and to young children. Considering the high concentration of EDCs found in breast milk, this is a disturbing finding. To date, very little is known for certain about the effects of EDCs on humans. Much of the evidence comes from research on laboratory animals and from hypothesising. But this should not provide comfort to the manufacturers. The effect of EDCs will eventually be established. The chemicals industry may think it is safe at the moment, but how long will this state of affairs last? The latest US court award against tobacco companies was a record $28bn. The effects of EDCs, however, are far more fundamental and further reaching than lung cancer and heart disease. THE MAIN CULPRITS

  • Artificial musks Artificial musks are fragrances added to a variety of products such as perfumes, cosmetics and laundry detergents. They are persistent and bioaccumulative; they mimic female hormones and are contaminants of the environment and the human body.

  • Brominated flame retardants A group of chemicals used as flame-retardants in fabrics and plastics. They are found in circuit boards, TVs, computers and household fabrics. Most are persistent and accumulative, and several have been identified as EDCs. Contamination of human breast milk by one group, the PBDEs, is doubling every five years in Sweden. The World Health Organisation has called for them not to be used where suitable replacements are available.

  • Bisphenol A Bisphenol A is used in the manufacture of linings for food cans and lids. It is not present in all cans, but consumers have no way of knowing which cans contain it. It is the main ingredient in polycarbonate plastic bottles. The chemicals can imitate the female hormone, and low-level exposures in developing mice have been shown to advance their puberty. Recent research has shown it can easily cross the placental barrier from mother to foetus in rats. It has also been found to contaminate human blood serum.

  • Phthalates A group of chemicals used as plasticisers in many PVC products, including vinyl floors tiles, toys, glues and inks, and as solvents in cosmetics. Four commonly used phthalates have been shown to disrupt the development of male sex organs in rats. A study on Puerto Rican girls with premature breast development found that they had higher blood phthalate levels than unaffected girls.

  • Alkyltin Alkyltin compounds such as tributyltin and dibutyltin are persistent and bioaccumulative chemicals used as preservatives, antibacterial agents and catalysts in the production of some plastics. They have immunotoxic effects and cause hormone disruption to marine molluscs, making female whelks grow penises.

  • Alkylphenols and their derivatives Alkylphenol ethoxylates are used as industrial detergents and are found in some household paints. In addition, derivatives of these chemicals, the alkylphenol phosphates, are used as UV stabilisers in some plastics. They are proven hormone disrupters which imitate the female hormones.


  • Increased rates of testicular cancer Testicular cancer increased in incidence by 55% between 1979 and 1991 in England and Wales. Testicular cancer is believed to result mainly from problems occurring during development in the womb, and EDCs are hypothesised as a cause of the increase. Recent research has provided support for the hypothesis that exposure to oestrogen in the womb increases the chance of getting testicular cancer later in life.

  • Early puberty in girls Researchers at Bristol University's Institute of Child Health have found that one in six girls in Britain is starting to show signs of puberty at the age of eight, compared to one in a hundred girls a century ago. No one knows why, but the hypotheses include exposure to hormone disrupting chemicals. Bisphenol, for example, has been shown to advance puberty in female mice.

  • Fewer boys being born In 1979, a major chemical accident in Seveso, Italy, released more than 30kg of toxic dioxin. Recent research has found that the higher the concentration of dioxins in men, the more likely they are to father girls rather than boys. Men under 19 at the time of the accident have since fathered 81 girls and only 50 boys. Other studies of birth ratios in countries as far apart as Denmark and the US have found a decreased proportion of male births.

  • Low sperm counts Much recent research indicates that sperm counts have fallen over the last half century. One of the more worrying studies, published in 2000, found surprisingly low sperm counts amongst around 40% of 18 to 20 year old Danish men.

    Jessica McCallin is a freelance journalist