CAO debate: bellies or buffers?

Is nonylphenol, a man-made chemical that feminizes male fish, causing bigger bellies in people? A recent peer-reviewed study found excess fat in liver and fat cells exposed to nonylphenol. (See: Wada et al., J Pharmacol Sci. 2007.) Such changes in fat storage lead to belly fat growth that is associated with diabetes, heart disease, and stroke.

Nonylphenol is produced by incomplete biodegradation of non-ionic surfactants. More than 500,000 pounds of non-ionic surfactants are produced each year in the U.S. Non-ionic surfactants are in auto and household cleaners, herbicides, pesticides, paints, deer repellents, and personal care products (sodium lauryl sulfate is the main ingredient in most shampoos). This is a partial list.

In fresh and saltwater, non-ionic surfactants biodegrade to nonylphenol. Nonylphenol enters the food chain and accumulates in the fat of fish and other animals. In people, higher Body Mass Index correlates with more of this alien hormone in our bodies.

How can we reduce our exposure to nonylphenol? In contrast to the build-up of nonylphenol in water, non-ionic surfactants in vegetated soil can be completely biodegraded by soil fungi and bacteria. By locating our homes, driveways, septic systems, and gardens away from our fresh and marine waters, the non-ionic surfactants can be completely biodegraded in a native plant buffer. The uneven surface and undisturbed leaf litter of a native buffer captures runoff much better than the smoother surfaces that people create in their landscaping. For homes on rocky land, bioswales can be created to treat the water that runs off roofs, driveways, and lawns.

The nonylphenol we are exposed to each day may seem insignificant. But, like one cigarette vs. a lifetime of smoking, the impacts add up. To protect human health and to protect wildlife, broad natural buffers should separate new homes, and their driveways, gardens, and septic systems, from our fresh and marine waters. Existing homes will not be required to meet the new standards in the Critical Areas Ordinance update, but homeowners may create bioswales to intercept non-ionic surfactants and other pollutants before they reach our waters.

Janet Alderton

Orcas Island