A primer on chemicals, fertility, and reproduction
Illustration: Keri Rosebraugh
Feeling unusually infertile lately? You’re not alone: according to a December 2005 report from the U.S. Centers for Disease Control and Prevention, around 12 percent of American couples reported having a hard time conceiving a child and bearing it to term in 2002, up 20 percent from the 6.1 million couples reporting such “impaired fecundity” in 1995. Although the reasons are complex and overlapping, one major factor may be nonstop exposure to low-level environmental pollutants like pesticides, dioxins, and phthalates.
Because these toxics are generated in ways and places beyond our immediate control, “You can’t shop your way completely 100 percent out of these exposures,” says Anila Jacob, M.D., a senior scientist with the nonpartisan Environmental Working Group. But changing some habits and product choices may help with the baby-making.
Here are some of the big bads of low-level environmental pollution, and what you can do to cut your exposure. Still, it’s not going to be green consumerism that ultimately solves this problem, but green chemistry: replacing these harmful substances at the manufacturing level with safer alternatives. And making that happen will probably require a hard nudge from lawmakers and regulators.
Substance: Bisphenol A (BPA)
Have I been exposed to it? Probably. The U.S. Centers for Disease Control and Prevention found BPA in 95 percent of people it tested.
How the hell did that happen? It’s used in polycarbonate plastic products like water bottles, shatter-resistant baby bottles, sunglasses, and CDs; epoxy resins typical of food and beverage can linings; and dental sealants.
Risks: Animal testing has shown that fetal exposure to even small amounts of BPA — lower than the levels found in the typical human — can lead to prostate cancer and breast cancer. Studies on rodents have shown reduced sperm counts.
Especially for you gals! BPA is implicated in polycystic ovary syndrome, which affects 1 in 10 U.S. women and is the leading cause of women’s infertility. This syndrome can also cause the growth of skin tags and excess hair, irregular periods, and obesity.
Scary! So how do I avoid this crap? Difficult. Canned foods are a big source of exposure, with beverages the lowest, pastas and soups the highest. So opt for glass packaging for these foods, or cook from scratch. Cut back on prepackaged infant formulas for the ankle-biter. Until manufacturers get the BPA out of polycarbonate (#7 plastic), switch to glass, polypropylene (#5) or polyethylene (#1, #2, #4) containers; trade out that polycarbonate water bottle for a stainless steel model; and don’t heat liquids or foods in polycarbonate containers or plastic wraps.
Have I been exposed to them? Yes, unless you’ve been living under a rock, and possibly even then. Around 80 percent of Americans are sporting phthalates in their bods.
How the hell did that happen? Manufacturers love phthalates: they impart durability and flexibility to all sorts of products, like cosmetics, nail polishes, fragrances, and grooming aids. They’re used to soften polyvinyl chloride (PVC) plastics, aka vinyl, which are the stuff of common consumer goods like children’s (and adults’) soft toys, garden hoses, shower curtains, chair cushions, car interiors, artificial Christmas trees, and so much more. Phthalates are also used in plastic medical devices such as blood-storage bags and intravenous tubing — and since phthalates are chemically attracted to fats, the blood draws them out of the plastic before it enters you.
Risks: Holy endocrine disruptor! In studies on rodents, phthalates caused testicular injury and developmental abnormalities. Reports published in 2002 and 2003 suggested that minute levels of phthalates were linked to sperm damage in men. A 2005 study led by biostatistician and epidemiologist Shanna Swan correlated exposure to phthalates in the womb with adverse affects on the genital development of boys.
Scary! So how do I avoid this crap? Swap out the soft PVC plastic products in your life for other materials: trade that vinyl shower curtain for fabric or nylon, say, or swap soft vinyl toys for high-quality silicone. (You’ll earn an extra-special green star, because PVC is environmentally evil from production to disposal.) The online Skin Deep Database is a good place to start looking for phthalate-free beauty and grooming products. Some hospitals are pledging to phase out PVC equipment, especially in newborn intensive-care units. Although the E.U., Japan, and other nations are banning phthalates in some products, like children’s soft toys and cosmetics, there’s no federal action in the works in the U.S.
Substance: Persistent organic pollutants (POPs)
Have I been exposed to them? Yep. Every living organism on earth now contains persistent organic pollutants, so why not you?
How the hell did that happen? Although there are various routes to exposure, most likely you ate them. POPs include organochlorine pesticides such as chlordane, dieldrin, DDT, heptachlor, hexachlorobenzene, and toxaphene. Because POPs resist biological, chemical, or photolytic degradation (they’re persistent, right?), they can last long after they were initially used, and easily travel via wind and water over long distances from where they were used. POPs bioaccumulate in human and animal tissue, and biomagnify in the food chain. So the higher up on the food chain you eat, the more likely and more concentrated your exposure to POPs. Mmmm, pass that bacon cheeseburger, willya?
Risks: Let’s just hold hands. Strong evidence indicates that prenatal, childhood, and adolescent exposure to POPs can cause irreversible damage to reproductive, neurological, and immune systems. POP exposure can also cause infertility.
Scary! So how do I avoid this crap? You can’t — they’re persistent, remember. But you can take some comfort in the fact that 140 nations from Albania to Zambia have signed on to the Stockholm Convention to ban the 12 top POPs and cut the total POPs entering the environment. Alas, the U.S. isn’t one of them. Still, you are (to some extent) what you eat. So reduce POP exposure by munching more organic foods and eating lower on the food chain. Mmm, pass that miso soy-cheese veggie burger, willya?
Have I been exposed to it? Probably. In a 2001-2002 study by the CDC, every one of 2,820 U.S. residents ages 6 and older — a nationally representative population sample — was found to have perchlorate in the urine, although at a level well below what the Environmental Protection Agency deems safe. It’s been detected in human breast milk as well. As of 2005, environmental releases of perchlorate had been found in 35 states.
How the hell did that happen? Perchlorate is a component of rocket fuels, fireworks, and some fertilizers; it travels through soils into groundwater, thence into drinking and irrigation supplies, and thence into milk, lettuce, and other foods. In a November 2004 report, U.S. Food and Drug Administration scientists reported finding an average 7.76 to 11.9 parts per billion of perchlorate in around 90 percent of lettuce samples from Arizona, California, Florida, New Jersey, and Texas, as well as an average of nearly 6 ppb in 97 percent of cow’s milk samples collected at stores in 14 states. “It’s so prevalent in food that we don’t feel comfortable telling people to avoid it” because they might give up too many nutritionally important foods, says Jacob of EWG.
Risks: Perchlorate can inhibit the uptake of iodide by the thyroid. And since pregnancy itself puts extra strain on the thyroid, perchlorate exposure may put pregnant women at greater risk of miscarriage, preeclampsia, and placental abruption, while their developing fetuses may suffer stunted birth weight and abnormal brain development.
Scary! So how do I avoid this crap? So far, the closest we’ve gotten to a national ban in the U.S. was a 2003 EPA directive banning agency staffers from publicly discussing perchlorate pollution. If you suspect it’s in your drinking water, get it tested — and if needed, install water filters that are proven to remove perchlorate (Brita and Pur won’t cut it here). Consult with your doctor to ascertain that you’re getting enough iodide, especially if you’re pregnant or considering pregnancy.
Substance: Polybrominated diphenyl ethers (PBDEs)
Have I been exposed to them? Sitting on a foam-cushioned sofa or chair, reading this article on your computer screen? Then that’s affirmative.
How the hell did that happen? PBDEs are employed as flame retardants in clothing, electronics, furniture, and carpeting. Particles get released when you sit down on a treated cushion; heat up a toaster, television, or computer; or walk on a treated carpet. The particles attach to dust, fabric, and more, and enter the water table via the laundry. When they burn, they can create more highly toxic substances, such as dioxin. When electronic waste is disposed of improperly, PBDEs can leach into the environment. And, like POPs, they’re bioaccumulative. PBDE levels have increased exponentially in our tender flesh since they started being used widely in the 1970s — which means if you were born from the 1980s onward, they may well have been in your mother’s breast milk.
Risks: There isn’t much research into the possible health impacts of PBDEs. In a study published in 2005, a single, low, in utero dose of the most common PBDE disrupted the neurological and reproductive development of some very unfortunate rats, which were born both hyperactive and permanently low on sperm.
Scary! So how do I avoid this crap? Difficult — tactics include effectively controlling dust and improving ventilation where you live and work. And, as with avoiding POPs, eating fewer animal fats. The Washington State Department of Health offers a comprehensive list of avoidance tips; as for buying furniture, electronics, and other products that are PBDE-free, a good resource is the Smart Shoppers PBDE Card from the Sightline Institute. This year PBDE bans have been proposed in California, Connecticut, New York, Hawaii, Illinois, Maine, and Montana; Washington passed a limited PBDE ban to take effect in 2008. Given ever-more-comprehensive e-waste and PBDE control in Europe, Japan, and elsewhere, the U.S. — where rules remain at the state level, and spotty — could become the global dumping ground for PBDE-full electronics. USA! USA!
Substance: Polycyclic aromatic hydrocarbons (PAHs). Fun fact: Although made up of only hydrogen and carbon, there are over 100 PAH compounds.
Have I been exposed to them? Chances are darn good that if you are reading this on a computer, you’re in an environment where you’ve been exposed to PAHs.
How the hell did that happen? Because they resist degradation in the environment, PAHs are sometimes grouped under POPs. PAHs are typically products of incomplete burning of carbon-containing fuels like wood, coal, oil, and gasoline — that’s soot to you and me — and are also found in coal tar, which is often used to make pavement sealer. Burning tobacco — those veils of secondhand smoke we all walk through these days — also creates PAHs. And they’re in charred meat.
Risks: Exposure to PAHs in utero has been shown to cause damage to DNA, chromosomal changes, and increased risk for childhood cancers such as leukemia. One study found that such exposure might trigger prenatal development of leukemia.
Scary! So how do I avoid this crap? Common sense suggests taking off your shoes at the door to avoid tracking PAHs into the house, doing your best to not inhale secondhand smoke, eschewing charred meat, and taking whatever actions you can to support clean energy generation. The EPA only regulates discharges of PAHs into waterways from industrial operations. Watch for action at the state and local level, such as the Austin, Texas, ban on coal-tar-based pavement sealants enacted in January 2006. (Asphalt contains a far lower concentration of PAHs, and some newer sealants are touted as virtually PAH-free.)
Substance: Alkylphenols, aka surface actant agents (surfactants): substances that reduce the surface tension of liquids, allowing them to combine more easily.
Have I been exposed to them? Do you clean the house? Wash your clothes? Paint your walls? Use contraceptives? Then ‘fraid so.
How the hell did that happen? Surfactants are commonly used in liquid detergents, as well as cleaning solutions, fragrances, air fresheners, and paints. And nonoxynol-9, a common spermicide often used in condoms, diaphragm creams, and other contraceptive products, contains an alkylphenol. Happy borking!
Risks: Alkylphenols act like little estrogen shots in the body, disrupting embryonic development of the reproductive system. And since they accumulate in tissue, they continue to mimic estrogen, basically forever. Male platyfish in alkylphenol-polluted rivers produce female egg yolk proteins, and lose the sperm-producing parts of their testes.
Scary! So how do I avoid this crap? Difficult. Alkylphenols are tightly controlled in the European Union and Canada, but less so in the U.S. The Sierra Club has asked the EPA to ban alkylphenol use in places where wastewater treatment plants are not equipped to remove them. Some manufacturers, including Procter & Gamble and Unilever, have substituted other chemicals for alkylphenols in detergents, and Wal-Mart is pressuring its suppliers to do the same.