There’s an important and ongoing debate in the U.S. and the EU about chemicals that may interact with the endocrine system to cause harmful effects in wildlife or on human health. In this post, we’ll work to answer some of the key questions driving the debate: What are endocrine disruptors? What does the latest science tell us about their potential impact on human health? Do they need to be regulated, and if so, what is the most sensible approach?
Endocrine activation is not the same as endocrine disruption
The endocrine system is the body’s hub for producing hormones that maintain a number of critical functions like metabolism, growth and development. The endocrine system can be activated by a variety of environmental stimuli such as everyday stress, exercise, exposure to sunlight, as well as exposure to natural substances in foods and some synthetic chemicals.
In the debate about whether certain chemicals are “endocrine disruptors,” what’s often misunderstood is that chemicals known or suspected interact with the endocrine system are not necessarily endocrine disruptors. Some substances do interact with the endocrine system and can cause transient effects, but these effects may be reversible and do not necessarily result in adverse health effects.
It’s also important to keep in mind that endocrine activity and the presence of adverse health effects from chemical exposure depends on many variables – the nature and dose of the substance, its timing, the type of effect and the condition of the body. Some exposures will not lead to any changes whatsoever, while others may elicit responses to which the body can naturally adjust and maintain normal function.
So, if the presence of an adverse health effect is what differentiates endocrine disruption from other endocrine activity, then an endocrine disruptor can be defined as “a substance that alters the function of the endocrine system and consequently causes adverse health effects” in humans or in wildlife.
Risk vs. hazard based approaches to regulation
After much deliberation, scientific bodies on both sides of the Atlantic – the U.S. Environmental Protection Agency (EPA), and the European Food Safety Authority (EFSA) and European Commission’s Endocrine Disruptors Expert Advisory Group, to name a few – have presented definitions that reflect this key difference in terms.
Where the U.S. and EU still differ, however, is in their proposed approaches to regulating substances that interact with the endocrine system. The EU is pursuing a narrow, hazard-based approach that provides an incomplete view of potential endocrine disrupting substances while the U.S. is following a broader, risk-based approach.
A hazard is a source of potential harm or injury. For purpose of our discussion, a hazard is a chemical that has the potential to bring about adverse effects in an intact organism. Risk is the chance that a person will actually be harmed or experience adverse effects from exposure to that chemical.
By way of analogy, we are “exposed” to hazards on the road every time we get behind the wheel – wet conditions, for example, and certainly other distracted drivers – but the risk of harm is relatively low for a given individual. And the benefits, such as reaching a desired destination, usually outweigh the risks.
The European Union’s proposed approach to categorizing chemicals as either endocrine disruptors or “suspected” endocrine disruptors is hazard-based. Under this categorization proposal, the EU would treat all substances shown to interact with the endocrine system as sources of potential harm, but without yet accounting for the notion that they present only minimal risk of actual harm.
No-nonsense Forbes contributor Trevor Butterworth wrote an informative piece about hazard vs. risk just yesterday, in which he quotes former chief scientific adviser to the British government Sir John Beddington as wary of the European approach:
[quote]’At extremely high doses, coffee can trigger cancer. But ‘if you just say this is a hazard, it is a carcinogen, or it is an endocrine disrupter, or whatever, and you just classify and regulate chemicals on that basis, and ignore the level of exposure,’ he said, ‘you’re hamming it.’ The key, he said, was to think about regulation as a ‘quantitative’ exercise and not simply a matter of identifying whether something was present or absent. ‘There’s a real danger that what’s happening in the European community, in particular, is the over-use of the precautionary principle and a failure to understand the difference between risk and hazard.'[/quote]
On the flip side, the approach of the U.S. EPA’s Endocrine Disruptor Screening Program (EDSP), while not without its own flaws, is risk-based and more scientific. The EDSP screens substances for endocrine related activity but it doesn’t stop there. Importantly, it considers exposure (how you come into contact with a chemical) and dose (the quantity, level or potency of the chemical) in determining endocrine activity and whether that activity can lead to an adverse health effect.
The importance of regulatory coherence and risk-based decision-making
Endocrine disruption is an example of a current area of potential regulatory divergence that may have a significant impact on trade. This week’s public session of the U.S.-EU High Level Regulatory Cooperation Forum in Washington, D.C. is an opportunity to capitalize on many years of progress in finding common ground on this and other regulatory and trade issues of mutual concern.
As the European Commission relates, there’s a lot at stake for both sides:
[quote]Regulatory barriers have long been recognised as the most significant impediment to trade and investment between the EU and the USA. With mutual investment stocks of €1.89 trillion, and trade in goods and services worth €700 billion annually, a more integrated and streamlined transatlantic regulatory environment would significantly reduce costs for producers and consumers on both sides of the Atlantic and improve the competitive potential of EU and US companies in the global economy.[/quote]
The goal of enhanced chemical regulatory cooperation is to ensure that even where regulatory differences persist, efforts are made to minimize regulatory costs and burdens while continuing to protect human health and the environment. If not effectively addressed, these differences may misallocate limited resources, restrict the use of beneficial chemicals, and create potentially unnecessary public health concerns – especially if not based on the best available science or on established risk assessment procedures.
That’s why it’s important that the U.S. and EU continue to engage in dialogue about the regulation of endocrine disrupting chemicals, including through enhanced scientific cooperation, in order to seek common approaches for studying and potentially regulating them. A lack of regulatory coherence on this and other core issues would be a lost opportunity for both sides as discussions on a U.S.-EU Trade and Investment Partnership agreement get under way later this year.