Send all your eco-inquiries to Jennifer Grayson at firstname.lastname@example.org. Questions may be edited for length and clarity.
I've been pretty freaked out about getting cancer from all the toxic chemicals we're exposed to. I now use a BPA-free water bottle and buy cosmetics that are free of parabens, harmful fragrances, etc. But a friend just told me that the worst toxins are something called dioxins, and there's nothing I can really do to avoid them. Is this true?
I consider it no small irony that the first syllable of the word dioxins sounds like die: So potent is this group of more than 100 cancer-causing industrial chemicals that the Environmental Protection Agency is currently considering setting the "safe" daily level for human exposure at seven-tenths of a picogram per kilogram of body weight. (A picogram, FYI, is one-trillionth of a gram.) To put it in perspective: With the much publicized toxic chemical BPA, you could be exposed to 50 million times that amount, and you'd still be within the realm of what's considered safe.
So why aren't dioxins dominating the headlines? (Save for the 2004 poisoning of Ukranian president Victor Yushchenko, who received an intentional, near-lethal dose.) They should be: They may be the most widespread noxious chemicals on the planet, present in the body fat of every human being on earth. They've been linked not only to cancer, but reproductive abnormalities, heart disease, and diabetes.
Your friend is right to be fearful -- dioxins are so ubiquitous in the environment that it's virtually impossible to eliminate our exposure. The chemicals are the byproduct of a number of industrial processes, including pesticide production, metal smelting, paper bleaching, and the production of PVC; they also enter the atmosphere through the burning of residential waste.
What's worse, these compounds take a tremendously long time to break down. So while thanks to regulations by EPA and industry alike, dioxin emissions have drastically declined over the past 30 years, much of our current exposure is being caused by the discharge of dioxins that occurred decades before.
The most grievous example of this is the Love Canal catastrophe, where residents of Buffalo, NY, were poisoned for decades after Hooker Chemical Company surreptitiously buried 200 tons of dioxins there in the 1950s. The area around the initial dump site is still off-limits.
Assuming, however, that you're not a resident of Love Canal (sorry, now Black Creek Village) or living next to a PVC plant, there is one step you could take to try to diminish dioxin exposure, though some may find it drastic: Go vegan.
It turns out that more than 95 percent of human exposure is through food, particularly meat, fish, and dairy products -- all dietary components that vegans do not eat. The cycle goes something like this: Airborne dioxins are deposited on soil and water surfaces; land animals eat contaminated plants (or fish filter tainted sediment in the water); the dioxins accumulate in the fat of those animals; you eat those animals or the food products they produce (like milk); the dioxins from those animals or animal products are stored in your fat.
But plants don't typically absorb dioxins, which is why researchers have found lower levels of the pollutant in the breast milk of vegetarian mothers, compared with those who ate a meat-intensive diet.
And if the breast milk of vegetarian mothers -- who consume some animal products like eggs and cheese -- is lower in these toxins, it stands to reason that a vegan diet would be the optimal diet for dioxin avoidance.
Sound too severe? Consider this: Environmental Working Group analysis found that a 130-pound American eating 4 ounces of cheese per day could consume more than one-third of EPA's proposed safe dioxin dose.
Most upsetting is that eating organic animal products doesn't seem to make a whole lot of difference as far as dioxins are concerned. While organic production methods do eliminate the dioxin exposure linked to chlorinated pesticides and herbicides, there is no way to regulate the dioxins that land on feed crops as a result of airborne pollution.
Even more unsettling: Research among egg farmers in the Netherlands and elsewhere in Europe found organic eggs to contain more dioxins than conventional ones, since organically raised hens spend more time outside, where they may consume contaminated soil, worms, and insects.
If you're not ready to take the vegan plunge and are concerned about dioxin exposure and cancer, you can still reduce your risk by purchasing leaner cuts of meat (broiling helps eliminate fat as well), choosing low-fat dairy products, cooking with olive oil instead of butter, and steering clear of contaminated fish, like farmed or Atlantic salmon.
Either way, you'll likely whittle your waistline while you cut your cancer risk -- and who can argue with that?