Wednesday February 20 2013
Chemicals found in children's toys could affect their development
'Poisoned by everyday life' is the front-page headline in the Daily Mail today, covering a new report that warns that chemicals used in everyday products are 'linked to a huge range of diseases.' It goes on to explain that, 'gender-bending compounds – used in toys, PVC flooring, car dashboards and credit cards – have serious implications for health.'
At first glance this coverage appears to be sensationalist. Many readers will be used to reading similar stories each week that appear to link everyday objects to a disease of some sort.
This may lead some people to dismiss the claims made by the Daily Mail out of hand. However, it is worth looking behind the headlines at what has the potential to be a significant problem for everyone's health.
What is the basis for these current reports?
The story is based on a report by the World Health Organization (WHO) and the United Nations Environmental Programme (UNEP) looking into concerns about the potential effects of endocrine (hormone) disrupting chemicals (EDCs) on the health of people and wildlife.
The report states that there is evidence that some widely used artificial chemicals can affect the hormonal systems of both humans and wildlife. This could lead to changes in the way these systems develop.
The report presents a complicated variety of issues, but does not come to any definitive conclusions about whether certain chemicals harm human health. However, a theme running through the whole report is the concern that we don't know enough about EDCs.
There are significant gaps in our knowledge about how different chemicals affect the biology and disease rates of humans. The report makes the point that the evidence we do have about the dangers of EDCs could just be the "tip of a (very big) iceberg".
Despite this lack of clear, direct evidence, the WHO/UNEP report uses very strong language, making the newspaper headlines partially forgivable in the circumstances. It would be unusual for the WHO to make such claims if it was not convinced that the evidence strongly suggests a significant problem.
What are hormone disrupting chemicals?
The WHO/UNEP report states that since its previous report on the subject in 2002, the science surrounding the health effects of EDCs has mounted. It says there is growing evidence that EDCs have harmful effects on the reproductive system, and has been linked to an increase in the rates of infertility, certain types of cancer, and birth defects.
This more recent report aimed to review the latest scientific evidence to assess the risk posed to human health by EDCs, and propose safety control measures if necessary.
However, assessing the risk of EDCs on human health is challenging as their effect depends both on the level and timing of exposure, the report says.
EDCs are used in cosmetics, flame retardants, plastic additives and pesticides, which could result in residues or contaminants in food and other products. Ultimately, the worry is that EDCs contained in these types of everyday products have started to contaminate the wider environment, which may harm people's health.
What health concerns have been raised about EDCs?
There are three strands of evidence that fuel concerns about EDCs. First is the increasing number of endocrine-related conditions in humans. These are wide ranging and include:
Some of the potential effects of EDCs may occur when a foetus is in the early developmental stages, when the sex organs are developing. This has been linked with certain gender-specific conditions, such as undescended testicles, which led to some media reports referring to EDCs as 'gender-bending' chemicals.
The second cause for concern is the harmful endocrine-related effects that have been seen in wildlife populations.
The third concern focuses on identifying which chemicals have potentially hormone disrupting properties. Nearly 800 chemicals are known to interfere with the hormone system, or are suspected of this. But only a small fraction of these chemicals have been investigated in tests capable of identifying harmful effects in living animals, including humans.
The vast majority of chemicals have not been tested at all, so there are vast uncertainties about the true extent of the risks these chemicals pose, and whether they could potentially disrupt the hormonal system.
There has been very little observational research linking EDC exposure to harmful health effects, even in chemicals known to be harmful. This means that there are many questions still unanswered.
What were the main findings of the WHO report?
As above, the report found that EDCs could have many potential harmful health effects, and that the timing of exposure to EDCs was crucial.
In some cases the effects of being exposed to EDCs are believed to be temporary. For example, in some adults the effects were only observed when certain EDCs were present, but disappeared when the exposure was removed.
However, exposure to some EDCs in early development can have permanent effects, with some only becoming apparent decades after the initial exposure. This is because some EDCs can affect the way tissues develop early on in life, a process known as 'developmental programming.'
The report concluded with the following remarks: "EDCs have the capacity to interfere with tissue and organ development and function, and therefore they may alter susceptibility to different types of diseases throughout life. This is a global threat that needs to be resolved."
Is there anything I can do to protect myself?
It is not easy to say. Human exposure to EDCs occurs through eating and drinking affected food and water, by breathing in dust, gases and particles in the air, or by being absorbed through the skin.
In both wildlife and humans, pregnant women can transfer EDCs to their unborn baby through the placenta, and after birth through the mother's milk. Children can have higher exposure to EDCs because they often put their hands in their mouths after touching things.
However, the WHO report does not advise how you can reduce your own, or your child's, risk of exposure to EDCs. The ubiquitous nature of EDCs in the modern environment means that there is currently no practical way to reduce exposure.
Therefore, the main focus of the report was on what governments and countries may be able to do to reduce people's exposure to EDCs on a larger scale. There is room for discussion about the potential effect of bans on certain chemicals, for example.
The media headlines, while a little sensationalist, did reflect the WHO/UNEP conclusion that EDCs do present a threat to human health, and that measures to reduce this threat should be considered. The report stops short of saying that EDCs definitely cause specific conditions, but it described the evidence as very strong in some cases.
Ultimately, this report tackles risks on a nationwide scale, so it didn't predict individual risk from exposure to EDCs. This will vary tremendously from person to person.
Similarly, it did not deal with how we can reduce our exposure to EDCs, or whether this is advisable. Instead, the report focused on national control measures.
The report also repeatedly highlights the vast gaps in the evidence surrounding EDCs and their effects. Although the available evidence suggests exposure to EDCs at certain levels is likely to be detrimental to human health, the reality is we still do not understand a vast amount about these chemicals.
It is hoped this report will spur on further research into EDCs so that these uncertainties can be cleared up and the necessary precautions can be made.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter.