Portland Harbor Chemical Analysis

We were not looking for specific chemicals. Due to this many of the chemicals we detected are not currently regulated or monitored – this is why we did this study. We do know that the chemicals we found are commonly found in urban rivers throughout the US. 

This study was the first step. It tells us more about the types of chemicals that are being found in the water. The next step is to figure out how common these chemicals are in the river, and at what amounts (concentration) they are being found. From there, we can do even more research to determine if they pose a risk to human health and/or animals/environment. The final step would be to determine if any of these chemicals need to be remediated. These steps all unfortunately take time.  

The Portland Harbor Superfund Site extends for several miles. We know that the type and amount of contaminants changes throughout the river. That means one place may have few contaminants, while another place may be closed to the public because of contamination. 

There are existing fish advisories and such for specific areas of the Portland Harbor Superfund Site. Check the EPA StoryMap for updated and current results. 

This study was not designed to test directly for human risk and safety. Rather, this is the very first study that can look to see what chemicals might be in the water of the river. Once we know what is there, we can do more research to figure out if any of those chemicals might be of concern.  

We do know that the chemicals we found are very common in urban rivers around the world.  

We did some preliminary toxicity testing, and we saw very low to no toxicity in our samples. We know for the PHSS, much of the known contamination is in the sediment, or the soil at the bottom of the river. The actual water column, where we took samples, is typically very low risk.  

We have provided all the information available in our report. The truth is that we, like you, are struggling to get enough information about chemicals in the environment to understand their potential impacts on health. This is why studies like this, and all toxicity studies, are so important. 

Hair care products are most likely getting into the water through the shower drains. As people rinse their hair, or use products in the shower, the products go down the drain, and many of these chemicals are not removed by water treatment processes. 

Medicines are not fully absorbed in the body. The left-over medicine is then excreted through the urine and feces. Once the toilet is flushed, the water goes into the sewers, and these chemicals are not removed by water treatment processes. 

This is a hard question to answer, because the PHSS is a large area, and the type and amount of chemicals changes across the site. To answer this question, we would need to do a risk assessment. This has been done by the Oregon Health Authority and the EPA for several sections of the river, to include Cathedral Park. That information is in the EPA Storymap, and OSU developed a one-page infographic about contamination at Cathedral Park and how the park can be used.

Exposure to these chemicals is likely limited even for those swimming in the water. 

The zebrafish assay is great because it does not require that we know anything about the chemicals in the water sample. It simply tells us if there is the potential for toxicity. Now, even if we see toxicity in the zebrafish model, that does not mean that we will see harmful effects in humans. Rather, the model can flag potential chemicals of concern. 

That said, we saw very low to no toxicity in our water samples. You can learn more about our zebrafish assay at this link.

The EPA hosts a quarterly meeting for communities – this is a hybrid meeting allowing in-person or Zoom attendance. 

The OSU Superfund Research Center also does work on the PHSS, and has several resources that may be of help.

We are publishing the results of this study in a peer-reviewed journal, to help move this type of science forward, and to raise awareness about other chemicals that are not currently being monitored. Once published, we will include a link to the paper on this project webpage.

Yes

This was a small study. A single study is never enough to change water quality standards. However, this study shows that there are other chemicals in the water, and can help inform future research that can look to see how much of the chemicals are in the water, and if they pose a risk to human health.