What is a Chemical Exposure?
Everything is made of chemicals – from the food we eat and the water we drink, to the clothes we wear and all of the products we use every day. Thus, exposures to all sorts of chemicals are normal occurrences, and frequent ones at that. But what does “chemical exposure” mean, practically speaking, to the average person?
A “chemical exposure” can be defined as the measurement of both the amount of, and the frequency with which, a substance comes into contact with a person or the environment. So phrases stating that a product or substance is “chemical free,” or, alternatively, is “chock full of chemicals” can be misleading or may not tell an accurate story about the potential effects that these chemicals might have on a person’s body or the environment.
The following science infographics may help put common questions about chemical exposures into perspective:
The air we breathe is composed of chemicals, including nitrogen, oxygen and small amounts of argon and carbon dioxide. In the morning, we brush our teeth with toothpaste that contains chemicals like fluoride to help strengthen and protect teeth, and sodium bicarbonate to help remove plaque from teeth. At breakfast, we might drink orange juice or coffee that contains naturally occurring chemical ingredients like acrylamide, fructose and aldehydes. Even water, the most abundant natural resource on Earth, is made up of two elements on the Periodic Table – hydrogen and oxygen.
Have you ever heard the expression, “If you can’t pronounce it, don’t eat it?” This graphic, below, and video from AsapSCIENCE demonstrates that natural foods like bananas can contain more hard-to-pronounce chemicals than some sweets. The video challenges a common misconception that manmade or synthetic chemicals are more toxic than natural chemicals.In fact, some of the most toxic chemicals occur in nature. For example, the botulinum toxin is a naturally occurring neurotoxin protein, produced when certain bacteria spores are exposed to low-oxygen conditions. This toxin can grow in containers of food that have been improperly processed, stored or preserved. Exposure to even a small amount of the botulinum toxin in contaminated food can cause botulism, a potentially deadly disease, but chemistry has a role in preventing the growth of this toxin. The preservative sodium nitrite is added to cured meats like lunch meats, hams, sausages, hot dogs and bacon to help prevent botulism.
Every day, many people drink coffee, tea or soda, beverages that contain a small amount of the chemical caffeine. At typical consumption levels – for example, four cups of coffee each day (containing 95 to 200 mg of caffeine) or five servings of soft drinks (containing 165 to 235 mg of caffeine) – caffeine might make you jittery, but it is generally not harmful. But, if a person were to drink around 118 cups of coffee – nearly 30 times a typical daily dosage – he or she would be imbibing a potentially lethal dose of caffeine. But most people are not likely to consume anywhere near that amount.One other example: infection with the botulinum toxin, a poisonous biological substance, can result in the potentially fatal disease botulism. But in very small quantities, botulinum can be used as a medication to treat muscle spasms, as well as in cosmetic procedures.These two examples, as well as the examples in the graphic below, help to illustrate why scientists say “the dose makes the poison” – just because a chemical is present in a product does not mean it is harmful in the amount present.