Pharmaceuticals in Urban Streams in Northwest Oregon

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[Steven Sobieszczyk] Hello and welcome to the USGS Oregon Science Podcast for Tuesday, August 25, 2009. I’m Steve Sobieszczyk.

For today’s show we will be discussing a recent study that examines the presence of pharmaceuticals in urban streams in the Tualatin River Basin here in Northwest Oregon.

In fact, the findings from this report are available today. You can view the report online by following the link in our show notes or head over to the USGS publications warehouse and download the report directly at pubs.usgs.gov/sir/2009/5119.

As modern science and medicine develop new and more effective pharmaceuticals, the amounts of these drugs being used has sky-rocketed. Increased use of drugs (everything from caffeine to codeine) has led to increased concentrations of such compounds in our streams and rivers. In the last few years a number of studies have been performed to determine the source, transport, and fate of such compounds. Joining me today, to discuss one such project, is Hydrologist Stewart Rounds of the USGS Water Science Center in Portland, Oregon. Thanks for joining me.

[Stewart Rounds] You’re welcome. Thanks for inviting me.

[Steven Sobieszczyk] First off, can you describe what type of pharmaceuticals you tested for and why?

[Stewart Rounds] Certainly. There were 21 different compounds that we’re testing for and these pharmaceuticals ranged from pain-killers to antibiotics and antihistamines. They cover most of the most commonly used pharmaceuticals in use in the country today. And we also had to have some considerations for the types of compounds that we could actually test for.

[Steven Sobieszczyk] So what kind of results did you see? What were the concentrations?

[Stewart Rounds] We actually had some good news. Most of the study was targeted towards determining how many of these compounds, and what concentrations we could find, in many of the urban streams in the Tualatin River Basin. So we took a lot of samples from Fanno Creek, which starts in the city of Portland and then winds its way through the edge of Beaverton, Tigard, and Tualatin. And we actually found very few compounds. The most commonly detected compounds we found were caffeine, which, of course, you find in coffee and a lot of caffeinated beverages, as well as some pharmaceuticals. The other compound we found most abundantly in the urban areas was cotinine, which is a metabolite, or a human by-product of nicotine. So it is derived from people who smoke. Those two were the most common found in urban areas. And most of the concentrations we found were very low. Very low concentrations below a tenth of a microgram per liter.

[Steven Sobieszczyk] How is it these chemicals made it into the streams? Is it a product of manufacturing? Or is it more of a by-product of people and their use and consumption of the pharmaceuticals or drugs?

[Stewart Rounds] Probably the most common source of these types of chemicals in streams would be through a wastewater treatment plant. Now many of the streams that we sampled don’t have wastewater treatment plants upstream. So, in Fanno Creek when we find caffeine and cotinine, those are from dispersed urban sources. So if someone takes their cup of coffee and dump the remains of that coffee cup in the street gutter. Well, that’s going to be washed eventually into the stream. And that helps you find caffeine in the stream. Same thing with cotinine. When someone smokes and discards their cigarette butts, that stuff’s going to end up in the stream. But downstream of a wastewater treatment plant there are many compounds that are delivered to the wastewater treatment plant from excretions from human waste that get delivered to the treatment plant and the treatment plants aren’t designed to remove all that material. So some of it gets through, and if that treatment plant discharges to a river you will find very trace concentrations of those compounds downstream.

[Steven Sobieszczyk] Since we’re discussing water quality and potential pollution problems, I’m curious, what is the concern that these compounds have for fish or wildlife or even for us?

[Stewart Rounds] Well, some of that concern is justified. It depends on where you are and what the concentrations are. The concentrations we found in this study, again, though, were fairly good news because the concentrations were so low that, at least according to the research we were able to find on ecological effects for some of these compounds it appeared that the concentrations were not of ecological concern. Now that said, there’s very little research that has been done to assess the ecological effects of many of these compounds, especially at trace levels. So, the effects are a bit unknown, but for the compounds where we have information, it appears that, in this case, the effects are minimal.

[Steven Sobieszczyk] What about processing and prevention? Are wastewater or drinking-water facilities equipped to deal with these types of compounds?

[Stewart Rounds] Generally, wastewater treatment plants are not designed to remove these type of compounds. They’re designed to remove oxygen-demanding substances. They’re designed to disinfect against certain biological vectors like virus and bacteria. They’re designed to remove solids and so forth. But they’re not specifically designed to remove things like pharmaceuticals. Fortunately, some of the processes in wastewater treatment plant do remove a good portion of the pharmaceuticals. And, in fact, we tracked water moving through the Durham wastewater treatment plant, and it turns out that most of the compounds that we tested for were removed with probably greater than 75% or 90% efficiency. There was one compound that wasn’t removed quite so well. But, in the future, perhaps, wastewater treatment plants might be redesigned a little bit. There has been some research showing that certain processes may be able to remove pharmaceuticals with a little higher efficiency.

[Steven Sobieszczyk] If our listeners are feeling a little uneasy and they want to be a little more responsible and reduce their impact, what advice do you have for them?

[Stewart Rounds] There are a few things you can do. First of all, since wastewater treatment plants are not designed to remove these compounds, the first thing you could do is, if you have unneeded pharmaceuticals (drugs that are sitting around in your medicine cabinet) and you need to get rid of them, don’t flush them down the toilet. Since the treatment plants aren’t designed to remove them, there’s no sense in delivering more of a load to that treatment plant. So, instead, there are actual federal guidelines, some relatively good advice for disposing of your unwanted pharmaceuticals. And that includes taking them out of their original containers, mixing them with old coffee grounds or kitty litter, putting them in a sealable bag or an old yogurt container and disposing of it with your household solid waste. Even better would be to take your unwanted pharmaceuticals to a “drug take-back” event. Those programs are available in some parts of the country. They’re not available in most parts yet, but that may change.

[Steven Sobieszczyk] Speaking of that, part of the reason we’re here doing the podcast today is to promote a “drug take-back” event here in Portland.

[Stewart Rounds] Yes, that’s a good point. Turns out that this Saturday, there is a drug take-back event sponsored by the Portland Police Department that is being held at Eastport Plaza.

[Steven Sobieszczyk] Which is off 82^nd and Powell in southeast Portland. We have links to the event in our show notes. So check there and get directions. Well, that’s all the questions I have. Thanks for giving me your time, Stewart.

[Stewart Rounds] You’re welcome.

[Steven Sobieszczyk] If you have any questions on this topic or any other water-related topics here in Oregon, feel free to contact us here at the USGS at (503) 251-3200. Also, links for this story and other useful items are listed in our show notes. So make sure to check that out. Thank you all for listening. Please check out other USGS podcasts at usgs.gov/podcasts. Until next time, I’m Steve Sobieszczyk.

This podcast is a product of the U.S. Geological Survey, Department of the Interior.

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Additional Resources

• USGS Scientific Investigations Report 2009-5119
• Proper Disposal of Prescription Drugs
• Portland, Oregon, "Prescription Drug Turn In"