Wednesday, November 17, 2004

In the water

(Hat tip: news)

Shampoo, bug spray and that morning cup of java linger in the environment after they're showered off or tossed down the drain, according to the most extensive study of Minnesota waters ever conducted. Caffeine, synthetic musk used in personal-care products, a flame retardant, an herbicide, the popular insect repellent DEET and other pharmaceuticals, products and chemicals are part of a complex brew being found in waters around the state.

We've got a couple of things happening here. Firstly, we do use a lot of chemicals, and we introduce naturally occurring chemicals into lakes and streams by our own habits. For instance, if you want to know whether a water source has been impacted by human activity, look for caffeine in the water. Secondly, our technology is constantly improving. We're learning how to detect increasingly tiny quantities of everything in the water.

The second point is a major key, since as soon as we can detect some contaminant, there's suddenly pressure to Do Something.

How much of a concern are these chemicals? Maybe not as much as the reports would have us believe.

Commentary: USGS uses their own conservative, broad brush term to cover all of the various types of organic chemicals found in wastewater. OWC for "organic wastewater compounds" generally includes all of the subcategories that pop up in various studies, such as EDs = endocrine disruptors; PAS = pharmaceutically active substances; PCPs = personal care products. Not all are necessarily endocrine disruptors, so some have suggested the "potential endocrine disruptors" term. Xenobiotics covers most everything. (A foreign substance, especially a synthetic chemical, foreign to a body or to an ecological system.)

Why pay any attention to this study?

Results of reconnaissance studies may help regulators who set water-quality standards begin to prioritize which OWCs to focus upon for given categories of water use.

We don't know what (if anything) a lot of these chemicals do, but this study at least tells us what's in the water. We can look at the effects of those chemicals first.

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