Does Kenton Really Have a Lead Problem?

Back in February, The Oregonian/OregonLive published maps of toxic heavy metals found in moss during research done by the U.S. Forest Service in 2013. While the maps are considered to have rough boundaries, there is little denying that they show Kenton as a lead hotspot, sending some Kenton neighbors to a near panic.

Seeking to better understand lead levels in the neighborhood, Kenton resident Zach Putnam has been actively investigating what he calls the lead “blob” supposedly floating over the neighborhood as part of an University of Oregon journalism project with Richard Percy and David MacKay.

Moss map

Pins show the locations of moss samples used to create The Oregonian/OregonLive’s heat map of lead levels.

“My house sits just inside the red part of the map, and I wanted to know more,” decided Putnam.

Based on Putnam’s findings, The Oregonian/OregonLive only used three data points in creating their lead map, and only one of those data points, taken near N Arygle and N Peninsular, showed a higher level of lead. The so-called blob is just the result of computer modeling visualizing those three points.

“A heat map is a misleading way to visualize so few data points,” said Putnam. “We do not believe there is a hotspot of lead contamination in Kenton as the Oregonian’s map indicates.”

Beyond the lack of data points, it’s not known how the measurement used in the moss sampling, micrograms per dry kilogram, translates to a level that might pose a health risk, so while a single moss sample showed a higher relative level of lead, it wasn’t necessarily at a level high enough to be unsafe.

The Oregonian/OregonLive actually did their own lead testing to attempt to verify the supposed hotspot only to find fairly low levels, under 43 parts per million, in all their tests.

In the ensuing months since the maps were published, Putnam has been collecting samples from across the neighborhood and getting them tested through the donation-based soil testing service offered by the Lead Safe America Foundation in SE Portland.

The results?

All Kenton samples have been under the federal level approved for play areas. As Putnam explained, “None of our Kenton soil samples tested above the federal hazard level for lead in areas where children might play (400 parts per million).”

Soil Tests

Some lead soil tests from Kenton

According to Putnam, the highest levels detected in Kenton from the roughly 60 samples taken thus far have been located at Portland International Raceway—potentially caused by the still permitted use of leaded gasoline on the track.

However, Putnam pointed out that his work isn’t complete: “We want to collect more data so we can prove this theory and better inform our community about local contamination risks.” Therefore, if anyone has soil results that they would like included in Putnam’s research, please contact him at

Putnam and his fellow classmates plan to publish their findings online soon and will give a brief presentation at the next Kenton Neighborhood Association General Meeting and Open House that will focus on soil and air quality on June 8th.