The Human Face Of Pharma
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June 19, 2006
Drugs As Environmental Pollutants
Chemist says responsibility for keeping pharmaceuticals out of the environment extends beyond drug manufacturing processes
Rachel Petkewich
Courtesy of Virginia Cunningham |
Virginia L. Cunningham |
No one thought about looking for drugs in the environment until the late 1990s, but they're there. Most pharmaceuticals enter the environment via patient use, and minimizing the amounts of drugs that are released is a multifaceted, ongoing issue, says Virginia L. Cunningham, GlaxoSmithKline's director of environmental sustainability sciences.
Since 2002, when the U.S. Geological Survey published its landmark reconnaissance study of streams and rivers, many researchers have reported finding more pharmaceuticals in the environment. "We know they are there," Cunningham says. "Now we really need to focus on whether it matters that the drugs are there."
Are these drugs affecting human health or aquatic life? She says pharmaceuticals don't behave like small-molecule, persistent, industrial chemicals that have been the focus of traditional environmental studies, so many research groups around the world are trying to answer these questions now. That includes a consortium of researchers organized by the industry group Pharmaceutical Research & Manufacturers of America (PhRMA).
"Research shows no appreciable risk to human health from the environmental exposure to these materials" at the levels they are detected, Cunningham says. "Personally, I think some subset of drugs in some places might have aquatic life impact, but most drugs probably don't," she says. The possible exceptions are estrogen hormones, antibiotics, and antiparasitical drugs in some places. "We need to focus on the ones that could be a problem and then decide how we manage those risks if any exist."
Cunningham holds a Ph.D. in physical organic chemistry and has worked on waste issues in the pesticide industry. In 1980, SmithKline (now GlaxoSmithKline) hired her to start dealing with environmental issues as a new drug is developed rather than after it is launched. Across the industry, she says, pharmaceutical companies ensure that any drugs and precursors from the manufacturing process are treated before release into the environment to protect aquatic life and ecosystems.
Cunningham suggests that the responsibility to protect the environment from potentially harmful levels of pharmaceuticals extends beyond just the pharmaceutical companies to doctors, consumers, insurance companies, and public utilities. She gives an example to illustrate the trickle-down effects: A doctor prescribes 30 painkiller pills, but the patient uses only five. When the medicine expires, the patient flushes the rest down the toilet. The drug eventually enters the environment via this waste stream.
Four problems arising from that scenario need to be addressed. First, doctors often prescribe excessive quantities of certain pharmaceuticals. Educating doctors about the broad ramifications of their action is key, and drug companies and government agencies are working on that now, Cunningham says.
The second problem is that, in the past, U.S. consumers have actually been advised to dispose of unused medicines down the drain. "Mostly, the advice that's coming out now is not to do that. For most places in the U.S., wrapping unused pharmaceuticals and putting them in the household trash is probably the best alternative. In some other parts of the world, pharmacies or communities have take-back schemes," Cunningham says.
Third, doctors have to work within the rules for health or prescription insurance copayments. Some of those rules encourage overprescription, which can result in improper disposal. "If you can get 100 pills for a $10 copay, why would you want 10 pills for $10?" Cunningham asks. "That's something that the U.S. insurance system isn't really set up to manage as well as it could be."
The fourth issue deals with utilities. "Many of these drug compounds and even drug metabolites can be degraded in wastewater treatment plants, but their removal requires efficient wastewater treatment plant operation," Cunningham says. "If pharmaceuticals aren't being treated, a lot of other compounds in wastewater aren't either." She notes that PhRMA has developed a model to predict concentrations of pharmaceuticals in the environment, which could be used to zero in on hot spots and perhaps identify high-concentration areas where enhancements to publicly owned treatment works might be helpful. Dealing with all four of these problems could take decades.