David Sedlak is concerned about the ecosystem and human effects of the pharmaceuticals and toxics we flush down the drain.

"Why is this city called Riverside?" David Sedlak, Professor of Civil and Environmental Engineering at UC Berkeley and TSR&TP Executive Committee member asked the symposium audience. Sedlak co-opted Toxics Jeopardy to kick off his presentation. The answer, for 200 points: Because there is a river nearby, the Santa Ana River, which is about 90% wastewater plus effluent.

The Santa Ana corridor is important for wildlife habitat. "Where does your aspirin, Prozac and caffeine go from Riverside?" asked Sedlak. "It goes to Anaheim Lakes near Disneyland." Other effluent dominated systems are common in the U.S., for example, the Trinity River and Boulder Creek. We sometimes intentionally take wastewater effluent and put it back into the ground without treating it. It's not just dry parts of the world that are involved in effluent recycling. The Thames River in England is one of the most effluent-impacted watersheds in the world.

Human waste is a significant source for pharmaceuticals in the environment.

Why should we be concerned about this? "It's not a question of whether you are affecting an individual," said Sedlak. "It's a question of whether you are affecting a whole population." The problem is endocrine disruption and feminization of fish, male fish developing female characteristics downstream from wastewater treatment plants. "If you cage the fish in the river or expose them in the lab to this wastewater effluent, you'll see feminization of fish." Estrogens at concentrations of nanograms per liter could be responsible. Estradiol and ethinyl estradiol, steroid hormones from birth control pills, are present in activated sludge effluent and these together cause feminization.

Sedlak cited an experiment in Canada where the researchers ground up birth control pills and put them into a lake. "At a concentration of ethinyl estradiol that's not far off from what we find in the wastewater effluent, we can cause a crash in the population of fathead minnows."

Sedlak wondered what other chemicals could be having similar effects. Prozac, caffeine, and carbamazepine (an anti-epileptic) have been found in sediments above levels that cause ecosystem problems. The male hormones in cattle-ear implants used in Concentrated Animal Feeding Operations get into the water stream and cause masculinization of fish. "We call this the Barry Bonds effect," said Sedlak.

What about people? Pharmaceuticals have been found in drinking water. Pharmaceutical companies such as Pfizer have been looking at the average concentration in surface water and comparing it to the therapeutic dose. Until recently, concentrations were way below therapeutic doses. Most of the concern for the future is about steroids such as birth control pills, and beta-blockers, erythromycin and camphor.

Sedlak said the shortcomings in research are in mixture effects, non-target effects, toxic metabolites and N-Nitrosodimethylamine (NDMA). He urged the audience to action. "There's a big opportunity for research here. I hope you think about these things in your car or plane ride home."

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