Periodycal #14: Odd side effects and the death of a battery pioneer

Plus the IARC's confusing carcinogen classification system strikes again

Welcome to another edition of the Periodycal newsletter. Once again I’ve failed to stick to a regular newsletter schedule, partly because I was on holiday for a week, partly because life with two young kids is often exhausting, and partly because the time I have had for work outside of work over the past month has been spent on some commissioned projects (which I should be able to share with you soon).

Because of this, I’ve decided to shift to just a monthly newsletter for the next few months. It’s more manageable for me at the moment and will reduce the guilt I feel when a week I should have posted rolls past and I haven’t had the time.

Anyway, to the content of this month’s newsletter! There’s a new edition of Periodic Graphics on unusual side effects of some medications, a throwback to some older graphics on lithium-ion batteries in light of the sad passing of one of the pioneers in the field, and more. Plus there’s the usual round-up of chemistry graphics tying in with upcoming dates or events, and a chemistry news and features round-up.

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Unexpected medication side effects

Click to view and download on the C&EN site

This month’s edition of Periodic Graphics comes off of the back of a conversation with my editor at C&EN and my personal experience of one of the side effects featured in this graphic. First, my editor brought up the effect of Pepto-Bismol turning poo black, an effect I’d not previously heard of. Then, I ended up on tetracyclines for a chest infection, which alerted me to their ability to make the skin of people taking them more sensitive to sunlight.

Turns out there are a number of odd and unexpected side effects of medications people take for a variety of conditions. This graphic rounds up some of the oddest I came across! I’m sure there must be other odd side effects that would also have been worthy of inclusion, so let me know in the comments!

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The death of a battery pioneer

Click to view and download this graphic on the Ci site

Last week Nobel Prize-winning chemist John B Goodenough, famed for his contribution to lithium-ion battery research, passed away. For a number of years, it looked like he wouldn’t make it to Nobel Prize recognition (the prizes are, rightly or wrongly, not awarded posthumously), but in 2019 he shared the prize with two other key figures in the field of battery science. There’s a nice obituary summarising his life and work in C&EN here.

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Is aspartame cancer-causing?

Aspartame has been in the news recently, with the International Agency for Research on Cancer (IARC) intending to classify it as ‘possibly carcinogenic to humans’. This has, of course, been seized on by some, despite the decision placing aspartame in the same IARC category as pickled vegetables – and people seem a lot less concerned about gherkins.

Click to view and download on the Ci site

My personal take on the IARC’s classification system is that it’s a largely awful piece of public health communication that leaves itself wide open to misinterpretation. The category aspartame now falls into ultimately indicates the evidence is not strong enough one way or another. Any substance or exposure tested by the IARC gets put into one of these five groups, and there’s actually only one substance that’s been placed into group 4 (probably not carcinogenic) in the history of all the substances that have been assessed.

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Upcoming chemistry tie-ins

Here’s a quick run-down of upcoming events or days and links to some relevant chemistry graphics from the archives:

• 7 July: World Chocolate Day – Chocolate chemistry

• 11 July: National Mojito Day – The chemistry of a mojito

• 16 July: National Cherry Day – The chemistry of cherries

• 16 July: National Ice Cream Day – The chemistry of ice cream

• 17 July: National Tattoo Day – Tattoo colorants and concerns

• 22 July: National Mango Day – The chemistry of mangos

• 28 July: World Hepatitis Day – Types of viral hepatitis and how to treat them

• 31 July: National Avocado Day – Why do avocados turn brown?

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Chemistry news and features

Here’s the regular selection of chemistry news and features I’ve found interesting over the past few weeks:

• Life on Venus? – In 2020 there was a brief period of hype for the possibility oof life on Venus when astronomers claimed to have observed the signature of phosphine in the Venusian atmosphere. However, follow-up observations showed no evidence of phosphine. The planet’s clouds of sulfuric acid don’t immediately inspire hope of harbouring life, but a recent study shows that the molecules of life, DNA and RNA, are actually stable in high concentrations of the acid. Don’t expect the discovery of Venusian lifeforms any time soon, but it keeps open the unlikely possibility that the planet’s acid clouds could have the capacity to support life.

• Cornish lithium is coming – This week it was confirmed that the UK’s first lithium mine will open in Cornwall, with plans to extract enough lithium for 500,000 electric car batteries per year.

• Disagreement over the environmental impact of cultivated meat – The carbon dioxide emissions related to the farming of animals is a key argument for cutting down our meat consumption. While lab-grown meat offers a promising alternative, a recent study has cast doubt on whether its emissions compare positively – though some of its assumptions have been challenged.

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That’s it for another newsletter! Got ideas for future graphics or newsletters? Drop them in the comments below!

Thanks for reading,

Andy