The gender gap
How toxic chemicals are turning male frogs into females
Tue, Jan 06 2009 at 6:28 PM
Even in the amphibian world, it's male versus female. But the fairer sex is edging out male frogs in an unfair battle of the sexes — the males are actually being transformed into females. Whether this is because they realized the ladies live longer or because toxic chemicals are disrupting their endocrine systems, ecosystems are suffering and certain types of frogs may even face extinction.
There's a vast array of chemicals to blame for the frog transsexual revolution, and some are common products you might use on a regular basis. Our society has grown dangerously fond of products that make our homes and yards so clean they're nearly sterile.
Diana Kaye, an owner of the organic personal-care products company Terressentials, goes over an abbreviated list of chemicals to avoid, all of which are endocrine disruptors and can be found in surprising places, from your cupboard to your cosmetics bag. "Butylated hydroxyanisole is a chemical preservative found in foods and personal-care products," she says. "Nonylphenol is used as a surfactant in household cleaning and cosmetic products, and hair colorings. Phthalates are used as a solvent in many personal-care and household products such as cosmetics, textiles, rubber cement and paper coatings." The list also includes parabens, which can be found lurking in many shampoos and shower gels.
So how do these endocrine disruptors work? "In very general terms, one way an endocrine disruptor can work is for it to mimic a natural endocrine that is a normal part of the animal's body," says Diana Papoulias, research fish biologist with the USGS's Columbia Environmental Research Center.
Exactly how the chemicals are able to transform males into females is the subject of continuous study. "There are several hypotheses about how a genetically male frog can become a phenotypic female frog or an intersex frog." Papoulias adds. "Most involve interference by the chemical [endocrine disruptor] on the sex steroids."
Stacia Sower, director of the Center for Molecular and Comparative Endocrinology at the University of New Hampshire, puts the plight into perspective. "Without question, these endocrine-disrupting compounds can have a myriad effect on the ecosystem. For instance, if there was species of frogs that was considered 'threatened' — the species has a chance of being eliminated and the population of frogs were exposed to key [endocrine-disrupting compounds] at key times that adversely affected their reproductive potential — then this species could be eliminated."
That's a sobering thought. But through learning more about the products we buy, we can become more knowledgeable and make safer and more pro-environmental choices. Next time you're in the grocery store, pay attention to the tub cleaner's or body wash's lengthy label before you buy it.
There are plenty of available choices that are nontoxic for both you and aquatic life. Products that don't contain harmful ingredients will mention that on the front of the container. Organic cleansers, body washes and shampoos are generally safe bets that you can find in a variety of stores from Target to Whole Foods. If we all begin to pay more attention, over time our actions might just help restore balance to the pond we all call home.