Paracelsus' poison

The WHO Endocrine Disrupting Chemicals Report: An Introduction

Yesterday the World Health Organisation released a report entitled “State of the science of endocrine disrupting chemicals - 2012

Endocrine disrupting chemicals are a broad range of substances that can interfere with how our hormonal systems work, by either mimicking natural hormones such as oestrogen, or altering their production and breakdown.

These chemicals have a wide range of applications, from pesticides to plastics. As we use plastics ubiquitously, from drinking from plastic containers to storing food in plastic containers to handling things like plastic credit cards, people are worried that these exposure may be harmful to our health.

The WHO report is a wide ranging survey of our understanding of endocrine disruptors, and builds on a previous 2002 WHO report.

The main report is nearly 300 pages long, and the Summary for Decision Makers is still substantial at 30 pages. I’m going to bet that it is the Summary the everyone reads, and I’m ready for a new round of Chemophobia from hasty reading of the Summary.

I’ll talk about some particular issues that arise from this report in the coming week, but before I start there is an issue that I thinks needs consideration

The main theme of the report is that more research is needed, and we have a lack of understanding of how these various chemicals impact on human health.

One of the people who talked to me about the report today asked a simple but important question that requires a complex answer.

If we are uncertain that these chemicals have particular health effects, why should we have any exposure to these chemicals in the face of this uncertainty.

It depends on the kind of uncertainly we are talking about. If we are uncertain that concentrations of chemical X cause diabetes for example, but the contentious concentrations are 100 times the existing maximum permitted intake of this chemical, there is sufficient margin of error to keep our current thresholds.

Especially if most people will never approach this maximum threshold of chemical X, it is acceptable to keep our current threshold levels until we have better data (we might revise them down a bit for an extra margin of safety).

An example is Soy products (okay these are natural products, not industrial chemicals, but the issues are identical).

There are a whole range of phytoestrogens in Soy, which might be protective against some forms of cancer, or might produce other cancers or interfere with male reproduction, and has even been linked to obesity.

Given that modest consumption of soy is unlikely to be involved with serious side effects, it makes sense not to prohibit soy products until we have firm evidence that particular levels are a risk.

That’s the general question out of the way.

Unfortunately, because of it’s very breadth of scope, covering so many chemicals, some issues are clearly differentiated.

The Summary for Decision Makers (the one most people will read) in particular often does not distinguish high-risk chemicals from low risk chemicals, or those where the evidence base is less complete. I’ll deal with some of these particular issues in the coming week.

So should you lick your credit cards? So long as you don’t make a habit of it, it should be fine.