Making sense of chemical stories: some considerations for chemists

June 29, 2014 at 12:44 pm | Posted in H&E Features | Leave a comment
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Making sense of chemical stories: some considerations for chemists

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Last month Sense About Science re-published its 2008 guide Making Sense of Chemical Stories, a report intended to address misconceptions promulgated by “lifestyle commentaries” that chemicals “cause only harm to health and damage to the environment” (Sense About Science 2014).

The document was lauded by the American Chemistry Council (ACC 2014) as “a guide to help put to bed the all-too-common myths about chemicals in our daily lives” – but is it? Or does it make the same sort of mistakes as the “lifestyle” commentators it aims to correct?

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The Sense About Science report Making Sense of Chemical Stories is born of a perception among chemists that chemicals have an image problem, that many people are in some way chemophobic, and that chemophobia stems in part from a series of popular myths which overblow the risks to health and the environment posed by man-made chemicals.

The chemists’ essential concern is that chemistry is unjustly stigmatised (Lorch 2014, Sanderson 2013), resulting in a slew of worries that this is reducing interest in studying chemistry, causing unnecessary loss of market for chemical products and, in general, people being “scared and anxious when they needn’t be, and complacent when they shouldn’t be” (Sense About Science 2014, p2).

The response embodied by Making Sense is to identify the misconceptions and debunk them. What is interesting about the debunking is the implied image which the authors have of the concerns and motivations of their target audience; this image is inaccurate and, as a result, the refutations of Making Sense miss their mark.

It is not that the observations of Making Sense are incorrect, it is that they address the wrong issues. This suggests that in addition to the myths themselves being misunderstandings, that chemists themselves also misunderstand the origins of what they understand to be chemophobia. In effect, there is a mythology about chemophobia which in turn needs to be debunked if there is to be societal accord on how best to use and regulate chemicals.

To see how this might be the case, we should first look at what the chemists perceive the myths to be, what they believe the debunking of these myths should consist of, and how that debunking may miss the essential points of the debates which give rise to the myths in the first place.

The myths of Making Sense

Misconception 1: You can lead a chemical-free life. The chemical reality is that you cannot lead a chemical-free life, because everything is made of chemicals. Chemicals are substances and chemistry is the science of substances – their structure, their properties and the reactions which change them into other substances. Claims that products are “chemical free” are untrue. There are no alternatives to chemicals, just choices about which chemicals to use and how they are made.

The basic point being made here is correct but trivially so: since everything is made of chemicals, it is indeed impossible to avoid them. The problem is, the trivial observation misses what is being communicated when products are described as “chemical-free” (as absurd as the phrase is), which is that the product is free of compounds which are of concern to the purchaser. (Whether or not they actually are free of these is a different matter; the point is that “chemical-free” is intended to indicate absence of substances of untrustworthy pedigree, not a total absence of chemicals altogether.)

The misunderstanding of what is being communicated is illustrated by the decision to juxtapose a quote from a Greenpeace web page about how the reader might not want untested chemicals in their body, with a list of the chemical constituents of a cup of tea. The intent is to reduce to absurdity Greenpeace’s point – after all, everything is ultimately an incomprehensible list of chemicals, so why fear the unfamiliar ones in one product while trusting the unfamiliar ones in a different product?

But again, this misses the issue. It isn’t the unfamiliarity of the compounds that is at stake, it is the expectation that when we are given things to eat or drink, when we buy furnishings for our homes or when we breathe in traffic fumes from the street, that these things are regulated for safety. The safety of tea is assured by food safety regulations; the point Greenpeace is making is that in the case of chemicals a similarly adequate testing and regulatory framework is not in place.

This could be disputed (and indeed is, at Myth #6) but the claim is not trivial – and indeed occupies considerable regulatory energy in Europe. The phrase “chemical-free” responds to observing, but not necessarily understanding, this expenditure of regulatory energy.

Misconception 2: Man-made chemicals are inherently dangerous. The chemical reality is that whether a substance is manufactured by people, copied from nature, or extracted directly from nature, tells us nothing much at all about its properties. In terms of chemical safety, “industrial”, “synthetic”, “artificial” and “man-made” do not necessarily mean damaging and “natural” does not necessarily mean better.

Greenpeace quote "Making Sense", in reference to myth #1

Quotes in “Making Sense”, in reference to myth #1

It is correct that the body does not recognise the ancestry of a chemical – just because something is “natural” does not make it any more or less safe. However, special attention is paid to man-made chemicals (and man-made preparations of “natural” chemicals) because of a current perceived lack of sufficient regulatory oversight.

If there is a misunderstanding that natural is better, it comes from misunderstanding why man-made chemicals are thought to be posing specific problems. Pointing out that “natural” chemicals can pose the same problems does not address the reasons why man-made chemicals are being singled out for regulatory attention; again, while the superficial misunderstanding is refuted, the fundamental root of the misunderstanding is left untouched.

Misconception 3: Synthetic chemicals are causing many cancers and other diseases. The chemical reality is that many of the claims about chemicals being ‘linked’ to diseases simply tell us that a chemical was present when an effect occurred, rather than showing that the chemical causes the effect. Caution is needed in reporting apparent correlations: it is in the nature of scientific experiments that many disappear when a further test is done or they turn out to be explained in other ways.

It is notable that the response doesn’t say the claim is not true – just that when a media story is published about a study which “links” a chemical exposure to a disease, that this is not the same thing as causing the disease.

The refutation goes on to offer some explanation of how to distinguish good evidence from bad (though not entirely satisfactorily, suggesting for example that readers look for randomised controlled trials as being the best sort of evidence of the health effects of chemicals – but this is a sort of evidence which does not exist because acquiring it is unethical).

What the refutation does not really talk about is what risk assessors and toxicologists actually do, namely the complex job of interpreting largely indirect evidence of harm gleaned from human epidemiological studies, animal and in vitro experiments into a picture of how a chemical might pose a risk to human health.

What is particularly difficult for risk assessors is dealing with preliminary evidence – those situations where there is an apparent link, where causation is not proven, but where action may nonetheless be warranted to prevent uncertain harm.

It is in this area, in the context of increasing prominence of the precautionary principle as a risk management tool, that the controversies and discussions take place. Much of the controversy is technical and no doubt mysterious to the outsider (it is complicated enough for the insiders); nonetheless, awareness of the problems is there.

If anything, this awareness increases the need for demystifying the uncertainties and research questions which are behind the misreported claims in the popular press of such-and-such a chemical “causing” cancer or other diseases. Placatory statements about many of these links disappearing over time contribute nothing to that demystification.

Misconception 4: Our exposure to a cocktail of chemicals is a ticking time-bomb. The chemical reality is that, although the language of “cocktails” and “time bombs” is alarming, neither the presence of chemicals nor the bioaccumulation of them, in themselves, mean that harm is being done. We have always been exposed to many different substances, because nature is a “cocktail of chemicals”. Modern technology enables us to detect minuscule amounts of substances, but the presence of such a small amount of a specific substance does not mean that it is having any discernible effect on us or on future generations.

It is true that just because we can detect a substance does not mean it is doing any harm. It is also true that nature is a “cocktail of chemicals”. Neither observation, however, addresses the two concerns which have pushed the “cocktail” issue into popular consciousness: firstly, that just because a dose is very small, there is no reason to assume it is not doing any harm; and secondly, that chemicals can have cumulative toxicity (a point acknowledged in the explanatory text in the Sense About Science document) but have never been regulated on this basis (not acknowledged in the text).

In a way, the refutation makes the same mistake as the one it is trying to address: that merely knowing the quantity of substance which is present says nothing about the toxic effect it might be having. What has changed is the scale at which this is thought to be happening, with the advent of research into endocrine disruptors, non-monotonic dose-response curves and windows of development suggesting that chemicals may be toxic at much smaller doses than previously thought.

In light of this, it makes no sense to say that just because a dose is tiny, it is of no concern. Tiny doses are of concern; what it is that makes them of concern is what should be demystified.

Misconception 5: It is beneficial to avoid man-made chemicals. The chemical reality is that, insofar as there is a ‘need’ for anything, synthesised and man-made chemicals have given societies choices beyond measure about what they are exposed to and the problems they can solve.

It is true that man-made chemicals have contributed enormously to society – modern life is based in chemistry. It is also indisputable that some chemicals have done a deal of harm.

FR quote in SAS 6 Myths

Quote from “Making Sense”, in reference to myth #5.

In this regard, Making Sense acknowledges problems posed by PCBs (now banned) and brominated flame retardants (now much less used), but presents their elimination as an example of the vigilance of chemical science.

That PCBs worked as dielectric fluids and brominate flame retardants as fire inhibitors does not mean the harms they pose to health should not have been better anticipated; the perception that this is in fact a failure of the vigilance of chemical science is what drives attempts to ensure that chemicals are better tested for environmental safety before being brought to market. The issue is not that there is no benefit to PCBs, nor that there was only benefit and unforeseeable harm; the issue is whether or not the harms and benefits can be anticipated such that the balance between the two can be further tilted towards benefit and away from harm.

Misconception 6: We are subjects in an unregulated, uncontrolled experiment. The chemical reality is that there is an extensive regulatory system that strictly controls what chemicals can be introduced: what experiments can take place, what can be used, for which purpose and how they should be transported, used and disposed of.

There can be no doubt that there is indeed a regulatory system. What is being debated, which the refutation here ignores, is precisely whether or not it is extensive enough.

This is the point of statements to the effect that chemicals are unregulated. Trivially, this is indeed an exaggeration; however, the efforts to improve access to information about chemical toxicity, to ensure chemicals are safe before being brought to market (which has not always been the case), to test them for potential toxic effects (such as endocrine disruption and cumulative toxicity) which have historically not been included in safety testing, to ensure that companies communicate to consumers what is in the goods they manufacture, the moves to address recognised weaknesses on controls on chemicals in imported goods, and so on all add up to a regulatory system clearly recognised as needing improvement.

It is this need for improvement which so much of the popular communication about lack of regulatory oversight and human exposure being an on-going “experiment” aims to capture. To baldly state that chemicals are regulated seems tantamount to saying that people shouldn’t be concerned about these debates, or these debates are somehow fictitious or spurious. Again, this doesn’t demystify, it just provides a superficial refutation to a debate to which the reader of Making Sense will be exposed almost every single day.

A better way?

The myths and misconceptions with which Making Sense is concerned are, like any misunderstandings, in genuine need of being addressed. The refutations on offer, however, are themselves over-simplifications, attempting to displace one set of misunderstandings of a complex discourse about the pollution of air, land, water and human bodies with another set.

The discourse, as it is happening, takes in concerns about whether or not people who have been wrong about chemical safety in the past can be trusted to get it right now (whether they are industry, chemists, politicians, NGOs or anybody else); what to do in the case of uncertainty about safety and how to regulate on the basis of incomplete information; where the boundaries of pollution lie (it is notable that the location of the problem has moved from factory outlets to face creams, and the scale from the visible to the parts-per-billion); among others.

These critiques are complex. They are indeed poorly understood by many of the people who are involved or in contact with them, be they consumers, journalists, politicians, campaigners or whoever. Many people are only exposed to the simplifications and do not necessarily understand why there is concern, only that they are concerned.

To address these over-simplifications with playful rebuttals simply rejects the concerns without addressing why the concerns are there in the first place; the refutations therefore miss their targets and, while they may convince a few people to forget about the issues, does nothing to advance a general understanding of what the issues are.

If we don’t advance understanding, it is difficult to see how we are going to reach informed participation in and agreement on matters of chemical regulation, rather than perpetuating the polarised stand-off we are currently encumbered by. Misconceptions are put to bed by education, not by denying problems even exist. As such, Making Sense feels like a lost opportunity to enrich the public’s understanding of many of the issues animating the debate about the use of chemicals in modern society.

IARC chief on cancer prevention; paper as BPA substitute; problems with informal pesticide use // Recent news highlights (June 2014)

June 11, 2014 at 10:39 am | Posted in 5&5 News & Science | Leave a comment
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June 2014 chemicals and
health news highlights

Prevention: Air of danger. The problem with prevention efforts is they usually focus on lifestyle changes for which the individual is responsible, such as stopping smoking and eating well, rather than regulatory changes that would place the responsibility on companies or governments to protect people from exposure to carcinogens, says IARC Director Christopher Wild. (Nature)

BPA substitute made from paper industry leftovers. In response to the controversy surrounding bisphenol A (BPA), chemists in the US have synthesised a safer, green alternative based on lignin – the structural component of plant cell walls that is generated as a by-product during papermaking. Their compound has similar mechanical properties to BPA, without showing endocrine disrupting effects. (ChemistryWorld)

The Toxic Brew in Our Yards. In much of the country, it’s time to go outside, clean up the ravages of winter and start planting. Many of us will be using chemicals like glyphosate, carbaryl, malathion and 2,4-D. But they can end up in drinking water, and in some cases these compounds or their breakdown products are linked to an increased risk for cancer and hormonal disruption. (New York Times)

BPA, epigenetic changes and heritable diabetes; soundness of US EPA’s evaluation of EDC dose-response curves; and more / June science digest #2 (lab and policy research)

June 10, 2014 at 10:53 am | Posted in 5&5 News & Science | Leave a comment
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June Science Digest #2 // Laboratory and policy research

Cancer, BPA | Dose-Dependent Incidence of Hepatic Tumors in Adult Mice following Perinatal Exposure to Bisphenol A. Apparently the first study reporting increased cancer incidence following BPA exposure. The researchers found hepatic tumors in 10-month-old mice which were exposed to 50mg/kg BPA in their diet. The researchers state that early disease onset, an absence of bacterial or viral infection and a lack of characteristic sexual dimorphism in tumor incidence “support a non-classical etiology”.

Science and Policy | Review of the US EPA’s Evaluation of Nonmonotonic Dose-Response Relationships as they Apply to Endocrine Disrupters. The US National Research Council’s appraisal of whether or not the EPA’s evaluation presents a scientifically sound and high-quality analysis of the literature on NMDRs. It recommends greater transparency and consistency to be achieved via systematic review methods, such as fuller documentation of search methods and use of risk of bias assessments. (See CEN coverage here. Also see the NRC’s review of EPA’s IRIS program.)

Semen Quality, EDCs | Direct action of endocrine disrupting chemicals on human sperm. A study of the action of 96 ubiquitous EDCs on human sperm, suggesting that many different EDCs can activate the same sperm-specific cation channel, inducing increase in motility response and other effects. The researchers conclude that EDCs interfere with various sperm functions and, thereby, might impair human fertilization. (See coverage in the UK Independent.)

Epigenetics, BPA, Diabetes | F0 maternal BPA exposure induced glucose intolerance of F2 generation through DNA methylation change in Gck. Study investigating whether or not BPA exposure can disrupt glucose homeostasis in second-generation offspring and any underlying epigenetic mechanism. The offspring were found to exhibit glucose intolerance and insulin resistance and down-regulation of the glucokinase (Gck) gene in liver. Methylation of the Gck promoter in offspring’s hepatic tissue was very different to controls.

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