Sure, not all of us may use the Pythagorean theorem in our everyday lives after graduation but science is is all around us and improving education and communication between researchers and the rest of us is becoming even more of a necessity. Research done well can create useful advancements and research done poorly (ex.
Doctor Wakefield’s now retracted Autism/MMR study) can hinder progress.
“A lie can travel half way around the world before the truth can tie it’s shoes.” — Unknown
This is where I hope to be of some help with my mad librarian skillz, bridging the gaps between scientists, doctors, and my fellow peeps. So this week, for Science Saturday, lets talk about CHEMICALS.
Me: Hey, honey. What are chemicals?
Hubby, yawning: Chemicals are the foundation of all life. They are the basis of all things in this universe. Goodnight.
Me: Oh, okay. Google, what are chemicals?
Google fetched me about 91,300,000 results in 0.63 seconds…
The word “chemical” often carries with it an unnecessarily negative connotation. There is a lot of talk these days about chemicals. “Don’t count calories! Count chemicals!” Fear seems to sell and companies are jumping on the shoddy marketing bandwagon to make a tidy profit. A notion that, if a kid can’t pronounce it, it must be avoided? My kid is an advanced reader so she sure can pronounce some humdingers! Or, nature makes better chemicals than a lab… Cyanide, arsenic, belladonna, poison ivy. Or there’s the “chemical-free” lifestyle. No. Just, please, no.
The Definitions of a Chemical
So let’s start off by answering the question “what is a chemical?” A blogging chemistry teacher considers her current working definition of a chemical to be, “any substance made of atoms, molecules and/or ions which has a fixed composition.” (1) This definition goes down to the teeny tiny, itty bitty, microscopic foundations. The food we eat, the water we drink, the air we breath, the planet we live on are all made up of elements found in the periodic table. Carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur are the six most common elements found in living organisms, like us. (2) Thus, all things with a physical basis are made up of chemicals.
Another science student blogger (with several posts on this topic you should go read instead of me) has this simple infographic to explain further what IS and what ISN’T a chemical (3):
Mmmm! Cupcakes are a delightful mixture of sugar, baking soda, and other chemicals and chemical reactions. Such a treat can create happiness, which is not a chemical although chemical reactions in the body contribute to the creation of those feelings in us as we savor the cupcake. Our body needs chemicals and we get those from the food that we consume, all of which are made up of chemicals.
Alas, how I wish hoping and dreaming of a clean house were enough but, again, thoughts are not chemicals and therefore do not work well on killing norovirus (a very unpleasant stomach virus easily passed around that doesn’t care what you think about it). So yes, I want and need my cleaning supplies to contain chemicals and so should you.
Even essential oils are made up of complex mixtures of chemical compounds. Here’s a graphic made by one of my favorite chemistry communicators, Compound Interest, on the compounds that contribute to the aroma of one of my favorite scents (4):
Safety and Toxicity of Chemicals
Next, let’s address the safety and toxicity of chemicals because if all things are made of chemicals and compounds then how can we tell what is safe and what could be harmful? It all comes down to amounts. Paracelsus, a Swiss doctor back in the 1500’s, is oft quoted when it comes to this issue:
“All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy.” — Parecelcus
At just the right amount or if used incorrectly, anything can be toxic. Or, even on the opposite side of the spectrum, too little may not even have any effects (good or bad). LD50 (lethal dose) is one method of measurement that can be used to determine the toxicity of a substance, or, the amount needed to kill half of the test population. The higher the toxicity, the lower the LD50 will be (i.e. it takes a smaller dose to cause harm or even death). (5) The measurement is often given in milligrams per kilogram of body weight. Even everyday substances humans consume could be harmful or even deadly in just the right amount, as presented here (6):
How does this apply to us consumers in our everyday dealings? Many methods of measurements like the LD50 and other research factors are used in determining the safety and efficacy in a variety of items such as medications, makeup, cleaning solutions, and food and drink. Safety and toxicity is quite complex, really. The advent of phone apps monitoring chemicals in products could be more of a hindrance as they feed into the unwarranted fears over chemicals. These apps are widely available on smartphones (except mine because it’s a dumbphone) and designed to be used by consumers to scan barcodes on household items ranging from makeup and shampoo to canned foods and produce and assigned scores.
While yes, it is important to take into account what we use and consume, sometimes one has to leave a good portion of it up to experts in the fields of science. The presence of a chemical compound does not equal hazardous. Remember, the dose makes the poison. Choose facts over fear.
Summary or TL;DR version:
Chemicals make up the substances we use in everyday life, including our own bodies. The dose of a chemical makes all the difference between whether it is harmful or safe.
Class dismissed. Go enjoy the weather.
(For those not in Iowa, it’s a rainy Saturday.)
Works cited and highly suggested reading materials for bonus points:
(5) Assessing Toxic Risk: Student Edition, Chapter One: The Dose Makes the Poison http://ei.cornell.edu/teacher/pdf/ATR/ATR_Chapter1_X.pdf