Natural vs Man Made Synthetic Chemicals Toxicity

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The term ‘chemophobia’ has been used on social media amongst chemists with increasing regularity over the past year. Defined as ‘a fear of chemicals’, more specifically it refers to the growing tendency for the public to be suspicious and critical of the presence of any man-made (synthetic) chemicals in foods or products that they make use of. Sense About Science, a UK-based charitable trust whose mission is ‘to equip people to make sense of science and evidence’, is attempting to combat this with a new free guide, “Making Sense of Chemical Stories”, for which the graphics in this post were made.

In these graphics, I wanted to emphasise the point that whether a chemical is natural or man-made tells us nothing about its toxicity. There are many chemical compounds, found naturally in plants, that are poisonous to humans in small amounts; similarly, there are many man-made compounds which are perfectly harmless unless ingested at very high doses. Although the first of the two graphics sorts natural and man-made chemicals into toxic & non-toxic categories, overall I wanted to show that in reality, this is an impossibility – all chemicals, if taken in a high enough dose, are toxic – even water, which we consider essential to life. “The dose makes the poison” is a rule that applies to all compounds, natural or man-made.

A common argument is that we’ve become accustomed to, and built up tolerance to, naturally-occurring toxic compounds, whereas we haven’t had time to do so with more recent synthetic compounds. However, consider that the most toxic chemical compound known to man is the naturally-occurring botulinum, one teaspoon of which could kill a quarter of the world’s population. It’s been around for millennia – and yet we still haven’t developed resistance to it. Plants, too, are constantly evolving, and producing compounds we’ve never before been exposed to; however, not every new compound produced by a plant is deadly to us just because we’ve never been exposed to it before.

Natural & Man-Made Chemicals - Dose Makes The Poison

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The second of the graphics further emphasises the relationship between dose and toxicity. Many fruits and vegetables contain compounds that have been shown to be toxic to humans. However, they are present in such comparatively minute quantities, that they are nowhere near the dose required for them to cause harmful effects.

In recent years, some groups have been in uproar over the presence of chemicals that are known to be harmful or carcinogenic in everyday cosmetics or foods. As an example, some groups maligned the presence of formaldehyde in some vaccines – despite the fact that there’s more formaldehyde present in your average pear (for the record, the quantity in both is well below the dose needed to cause any harm). The key fact that is often overlooked about chemical testing is that it often involves concentrations of chemicals well above those that we are normally exposed to. Just because a chemical is harmful or carcinogenic at very high doses, does not necessarily mean it will have any ill effects at the doses we experience. Food regulation exists to prevent harmful levels of chemicals from being used in products we buy – if the levels were harmful, they simply wouldn’t be allowed on the shelves.

Another prime example of the spread of chemical misinformation is the self-styled ‘Food Babe’s’ poorly informed attack on the use of azodicarbonamide (unceremoniously dubbed ‘the Yoga Mat chemical’) in Subway’s bread, which is excellently debunked here. It’s a sad state of affairs when someone without a chemistry or food science degree, and with little more than a simple knowledge of the subject, is able to spread such misinformation about chemicals much more easily than those who wish to educate the public to better evaluate such stories for themselves.

That’s why I was eager to get involved and support Sense About Science’s initiative in creating these graphics for their new guide. Whilst, as ever with this kind of information, it’s unlikely to reach those in need of it most, it will hopefully encourage those who do read it to more neutrally evaluate claims about chemicals in their food and personal care products, and to discard their pre-conceived notions about natural and man-made chemicals.

You can view and download the Sense About Science guide on their site here, where you can also download the graphics in this post, or request hard copies. Additionally, I’ve been inspired by the guide to create a few other graphics, unaffiliated with Sense About Science, which I’ll be sharing over the next week or so. Please share their guide far and wide, and help stem the flow of chemical misinformation!

EDIT (07/06/2014): I’ve altered the graphic to remove MSG from from the synthetic section, and replace it with propylene glycol. MSG was included as it was commonly synthetically produced for use as a food additive. However, having been informed that it’s now more commonly produced from bacteria, it doesn’t fit in the man-made section, so I’ve altered the graphic to reflect this.



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