Chemicals are bad, m’kay?

So it’s summertime once more. The lotus flowers are in bloom, everyone’s enjoying ice cream and relaxing in shady spots with cold drinks. There’s just one drawback. Mosquitos.


I may be a total pacifist usually, but that does not extend to mosquitos. With good reason, because despite their diminutive nature, mosquitos are the most deadly creature on this planet, infecting 10% of the human population with some kind of disease every year, and consequently being responsible for more human deaths than any other animal. Lovely.

Unfortunately, a couple of minutes with Google to look for information on insect repellents comes out with some gross misinformation. This makes me sad, so I thought I’d try and do what little I can to try and straighten out a few facts.

1. “Chemicals are evil!!!!!1”

No. They’re not. In fact, you’re made of chemicals. Retinal is a chemical. It allows you to see things. Hemoglobin is a chemical. It lets your blood carry oxygen around your body. Fructose is a chemical. It tastes nice.

Yes, I realise that there are some chemicals which you don’t want on your skin (I do have a degree in chemistry, after all), and there are a lot which should have actually been tested more thoroughly before being used widely (I’m looking at you, American farmers with your DDT) – but talking about “chemical-free insect repellent” is just untrue. Yes, citronella oil is natural, but it contains a few chemicals (such as citronellal, geraniol, and limonene) which are actually what keep the bugs away. Please stop using the word “chemical” like it’s some kind of villain.

2. “Natural things don’t work”

These are the overcompensation for those who have the previous approach (weird how the internet is a soapbox for polarised opinions). Frankly, a lot of natural things do work. Citronellal and geraniol genuinely do repel insects quite effectively. That’s precisely why plants evolved with them. In fact, some of these function in very similar ways to synthetic insecticides we’re all more familiar with. At least a few industrial pesticides (and medicines) are actually based on modified versions of naturally occurring chemical compounds.

Just remember that while natural things can sometimes be no less effective than synthetic things, being “natural” does not mean something is safe. Snake venom is natural. So is the gympie gympie stinging tree*.

In short, try not to be closed minded. Yes, citronella candles do keep mosquitos away. So does DEET. You might not like DEET, but if you’re going to an area prone to malaria and Dengue fever, I can guarantee that you’ll like those even less.


* The gympie gympie stinging tree is a tree which is covered entirely with fine hairs which deliver a potent neurotoxin. This toxin causes agonising pain which can, in particularly unfortunate cases, last for months. Even years, so they say. Oh, and in severe doses, that toxin is potent enough to kill a horse. In case you hadn’t guessed, this plant is found in Australia…

About Invader Xan

Molecular astrophysicist, usually found writing frenziedly, staring at the sky, or drinking mojitos.
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