During the recent heat wave, I tried to keep my air conditioner use to an absolute minimum. To keep my stink at bay, I loaded up on antiperspirant. Which got me thinking: What are the environmental and health impacts of deodorant?
Let's start off by clarifying some terminology. Antiperspirants, as their name suggests, reduce sweating. The active ingredients in these products are thought to work by temporarily plugging up the sweat ducts in your armpits. Deodorants, on the other hand, mask funky smells with perfume or eliminate them with antimicrobial agents. (Sweat by itself doesn't stink; it's the combination of sweat and bacteria that produces B.O.)
Green-living acolytes don't seem to be as concerned with the environmental impacts of these products as they are with the potential health effects. The ingredient with the worst press is aluminum. A few research papers—and quite a few e-mail forwards—have suggested that aluminum might contribute to both breast cancer and Alzheimer's disease. But according to the National Cancer Institute, there is no conclusive evidence connecting deodorant or antiperspirant use to the subsequent development of breast cancer, although it notes that more research is necessary. (The Institute says the same thing about parabens, an estrogen-mimicking preservative that's in some underarm products.)Meanwhile, the Alzheimer's Association notes (PDF) that studies have been unable to confirm a causal link between aluminum and Alzheimer's, and that "few experts believe that everyday sources of aluminum pose any threat." (You can read more about the topic here.) People with kidney disease, however, should consult a doctor before using antiperspirant.
For what it's worth, the Lantern continues to use a traditional, aluminum-based antiperspirant, though your precautionary threshold might be lower than hers.Personally, she's more concerned with the environmental impact of procuring that aluminum—as we've noted in a few previous columns, mining and processing bauxite ore can be very energy-intensive. However, if you want to use an antiperspirant, you have to live with aluminum: It's in every active ingredient approved by the FDA for over-the-counter use. To avoid it, you'll have to switch to a deodorant.
In the deodorant category, the antibacterial chemical triclosan is getting a lot of attention. The research is still emerging, but recent studies have raised concerns that triclosan may affect human hormone regulation and be contributing to antibiotic resistance. (The FDA is currently reviewing the evidence on triclosan's safety in consumer products; its findings will be ready for the public next spring.) Meanwhile, when triclosan washes off our bodies and down the drain, some of it ends up in surface water. There's evidence to suggest that, at current levels, it may be toxic to some aquatic organisms or have impacts on their endocrine systems. There are a number of deodorants without triclosan, however, so you should be able to avoid it if you choose.
What about so-called "crystal" underarm products? These are made from potassium aluminum sulfate, and typically sold in the form of solid, crystallized rocks. Despite some manufacturers' claims to the contrary, they do contain aluminum. Likewise, claims that the molecules in these products are "too large" to pass through the skin are "bunkum," says Chris Exley, an inorganic biochemist who specializes in aluminum. Potassium aluminum sulfate does dissolve more slowly than the aluminum compounds used in antiperspirants, he says, so it's possible that using a crystal would lower your exposure to aluminum. But there's been no research to demonstrate this. (With regards to the "naturalness" quotient: Potassium aluminum sulfate is a naturally occurring mineral—but it can also be produced artificially, by reacting bauxite with sulfuric acid.)
Crystal odor-killers can, however, win on the packaging front, since it's possible to get a lump of long-lasting rock in a simple cardboard box, thereby eliminating the need for a plastic container. You can also buy unwrapped bar deodorants, or refillable powdered and roll-on deodorants. And there's always the option of making your own deodorant and keeping it in a reusable container. When it comes to more traditional options, the Lantern knows of one brand of stick deodorant whose packaging is fully recyclable—Tom's of Maine—and the metal cans that spray products come in are often recyclable, as well.
However, sprays are the worst choice from an air pollution standpoint. According to a spokesman for the California Air Resource Board, these products are likely to have the highest amount of volatile organic compounds, which contribute to the formation of ground-level ozone, a key component in smog. By the same token, he suggests choosing fragrance-free options, as the ingredients used to deliver the perfume to your armpit may also contain VOCs. (You needn't worry about your deodorant contributing to the hole in the ozone layer—ozone-depleting chlorofluorocarbons were phased out decades ago in the United States.)
What's the most straightforward way of reducing the impact of your antiperspirant or deodorant? Use less of it. According to a 2007 New York Times article, stink-averse Americans tend to be overzealous about our underarm hygiene. In fact, neutralizing your essence might harm you in the romance department: A body odor researcher quoted in the Times notes that there's experimental evidence to suggest that humans prefer mates with different immune systems, and that armpit odor is one way of signaling that difference. Maybe we should all just make like Walt Whitman, who crowed in Song of Myself that the scent of his armpits was an "aroma finer than prayer." However, if you do decide to forgo any underarm product, just be wary of the rebound effect. If ditching your Mitchum means you end up taking more hot showers or laundering your clothes more frequently, your environmental savings might be a wash.