Monday, September 01, 2014

Urine Trouble

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Experts examine how to flush trace pharmaceutical chemicals from Phoenix’s water supply.

Every time Phoenicians flush their toilets, they send toxic pee to the sewer. This flood of urine – filled with chemicals from painkillers, hormones and antibiotics – ends up in wastewater treatment plants that cannot completely remove the medications before the pharmaceutical soup finds its way to the state’s lakes, streams and rivers, threatening wildlife and worrying scientists and regulators.


A 2002 U.S. Geological Survey report found low concentrations of prescribed, over-the-counter, and veterinary drugs in most of the 139 streams it tested in 30 states, including Arizona. In 2010, Arizona State University Associate Dean of Research Paul Westerhoff co-published a baseline study of pharmaceuticals in Arizona waters, including samples from eight wastewater treatment plants, which contained trace elements of pharmaceuticals and chemicals found in sunscreens, insect repellents, antibiotics and painkillers.

Evidence shows certain hormones, such as those found in birth control pills, can distort and cause cancer in the reproductive organs of fish, as well as brain and neurological issues, according to the Arizona Department of Environmental Quality. Northern Arizona University professor Catherine Propper recently discovered that chemicals found in effluent released by Flagstaff treatment plants interfere with thyroid function in frogs. University of Arizona researcher Shane Snyder found that both naturally occurring and prescribed hormones alter the reproductive organs in some of Lake Mead’s fish. The same pollutants flow from Lake Mead into the Colorado River and then into Central Arizona Project water. The big issue is population density and the need to recycle wastewater, Snyder says.

Under Snyder’s leadership, University of Arizona will break ground in December for a 23,000-square-foot Water and Energy Sustainable Technology Laboratories building to study emerging pollutants. The labs will become part of a site for a new treatment plant being built by UA’s partner, Pima County Regional Wastewater Reclamation Department. “We also have fish and invertebrate toxicology laboratories, where we can expose fish to different qualities of water before and after a particular treatment process,” Snyder says. “In this way, we can identify the most efficient processes for treating water to reduce impacts to the environment.”

While science works to measure and reduce pharmaceuticals in wastewater, it leaves government officials with a nagging problem: what to tell the public. The U.S. Food and Drug Administration still suggests flushing some drugs that can be lethal to small children and pets, while the U.S. Environmental Protection Agency warns the public not to flush medications or send them to the landfill. The agency prefers people take advantage of annual pharmaceutical take-back days held in most cities, including Phoenix. Snyder says “green chemistry,” the effort to make medications environmentally friendly, is gaining traction, but is more common in personal care products and far more complicated for pharmaceuticals. The most likely solution, he says, would mean changes to treatment plants that would allow fewer medical compounds to slip through.

Solutions are not easy. There are currently no regulations to monitor for these pollutants, no standardized list indicating which pharmaceuticals to monitor and no standardized testing methods, says Charles Graf, senior hydrologist for the Phoenix Water Services Department’s Water Quality division. Technology to remove more medical compounds from the wastewaster at Arizona’s largest treatment plant, at 91st Avenue along the Salt River, is expensive and untested, says Randy Gottler, deputy director for Phoenix’s Water Services Department, Environmental Services division. Gottler worries about the unintended consequences of untested water treatments. For example, to remove pollutants from the 140 gallons of effluent it releases every day, the plant uses bacteria, disinfectants and polymers, which bind to smaller particles and make them easier to remove from the final outflow. However, these treatments can reinvigorate some medical compounds the body degrades, or make byproducts that are nearly as worrisome, Gottler says. “It’s a very complicated problem,” he adds. “We’re just beginning to understand it, and there are a lot of unanswered questions.”

Toiletry Chemistry
Chemicals commonly found in Arizona wastewater:
• oxybenzone from sunscreen
• caffeine
• sucralose from artificial sweeteners
• DEET from insect repellent
• sulfamethoxazole from antibiotics
• acetaminophen from painkillers
• dilantin from seizure medications
• triclosan from antibacterial soaps

Source: “Trace Organics in Arizona Surface and Wastewater,” American Chemical Society, 2010.

 

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