The Uncertainty of EPA’s Human Health Risk Assessment

In the 176 pages of the EPA’s Final Site-Wide Human Health Risk Assessment, published on February 10, 2021, the EPA found that the risk we are in is, basically, uncertain.

Under Section 6.3.4, the EPA acknowledges it does not have a chronic inhalation reference concentration for arsenic. Similarly, the Agency for Toxic Substances and Disease Registry (ATSDR) has declined to derive an inhalation minimal risk level for arsenic due to insufficient studies. Consequently, the assessment of arsenic levels in the HHRA falls under uncertainties that cannot be quantified. Even more troubling, the direction of the effect of these uncertainties is also unknown.

Wait—what?

The EPA relies on a Risk-Based Specific Concentration (RSC) level to interpret chronic inhalation arsenic toxicity. For arsenic, the RSC is 0.0023 µg/m³. Past air monitoring data collected in the area consistently showed arsenic levels exceeding the RSC. Yet, under Section 6.3 of the HHRA, the EPA cites “temporal uncertainty” due to the lack of current site-specific air quality data, with the most recent data collected in 2009 at the Sheep Creek air monitoring station. This lack of updated data affects assessments of arsenic and other heavy metals such as lead, cadmium, and mercury.

But why the lack of data? Because of decisions the EPA made while conducting the HHRA. There could and should have been no reason for such uncertainty.

Community Efforts and EPA’s Response

After a petition signed by over 100 concerned residents of Northport requested updated air monitoring, the EPA announced it would not conduct new air monitoring for the HHRA.

In 2017, agreeing with the communities concerns, the Washington Department of Ecology’s Air Quality Program used existing data to evaluate conditions and determine whether additional monitoring was necessary.

Ecology’s Senior Toxicologist, Matt Kadlec, concluded:

“Previously interpreted air monitoring data suggest that current emissions from the Trail smelter continue to influence upper Columbia River valley air quality. These findings reinforce the need for current PM10 speciation monitoring in the upper Columbia River Valley near the international border and Northport area.”

Despite this clear recommendation, the EPA did not act, leaving critical data gaps that contribute to the HHRA’s uncertainties. These gaps compromise the assessment’s accuracy and may pose serious health risks to the community.

A Legacy of Neglect

Generations of Northport residents have witnessed the consequences of these uncertainties—not just through anecdotal evidence but also through community health surveys. The 2011 community survey caught the attention of Dr. Josh Korzenik, Director of the Crohn’s and Colitis Center at Brigham and Women’s Hospital and a leading researcher in inflammatory bowel disease (IBD).

In 2011, Dr. Korzenik and his team, in collaboration with Massachusetts General Hospital and Brigham and Women’s Hospital, conducted an independent study focused on current Northport residents (excluding past residents). The results were alarming. When interviewed by the Spokesman and other national newspapers Dr. Korzenik noted:

“Diagnosed cases of ulcerative colitis or Crohn’s disease in Northport were 10 to 15 times higher than national averages. I’m not aware of any other cluster like it,”

And this does not even account for the myriad of other rare and devastating illnesses that have plagued both past and present residents.

Critical Questions, Unanswered

Given these findings, why did the EPA not conduct blood lead level tests for residents—especially children—during its assessment? Why didn’t the agency offer blood, hair, or nail testing for any interested residents to gain a clearer understanding of the bioaccumulation of heavy metals? Such testing would provide valuable data to address the community’s ongoing health crisis and identify the role of environmental toxins.

The findings of the Northport Community Health Survey and the EPA’s failure to act speak volumes. The effects of Teck’s negligence, combined with the EPA’s inaction, are painfully clear to those living with the consequences.

The EPA’s quote below summarizes their conclusion of the HHRA they conducted. It is not just inadequate—it is inexcusable.

“Uncertainties that cannot be quantified and the direction of the effect of the uncertainty is also unknown.” – Environmental Protection Agency, Region 10

Take a moment to review the Northport Community Health Survey Results and consider the devastating human cost of inaction. For us, the direction of the effects of this negligence is anything but uncertain.

A Path Forward: Addressing Data Gaps and Health Risks

With the Upper Columbia River site recently designated a Superfund site—including areas in and around Northport—there is an opportunity for the EPA to take meaningful action. Installing 3–4 permanent air monitors in and around Northport to measure both PM2.5 and PM10 levels of heavy metal toxins, including arsenic, cadmium, lead, and mercury, would provide accurate, real-time data.

The EPA could also collaborate with the Washington Department of Health and medical research teams to analyze the high prevalence of autoimmune diseases documented in the community. These findings could help establish more accurate safety thresholds for chronic inhalation exposure to arsenic and reevaluate current standards for other heavy metals.

At a minimum, the EPA should consider conducting community-wide blood lead level testing. Providing residents with heavy metal testing kits—complete with instructions and prepaid return packaging for hair and nail samples—would offer a simple and effective way to better understand bioaccumulation in the community.

Although the EPA does not typically oversee medical testing, it has the authority to partner with government agencies, hospitals, and research teams to conduct in-depth studies. Such collaborations are especially critical when human health risk assessments are involved.

The EPA is currently working on a Community involvement plan. If you would like them to provide blood lead level testing and heavy metal testing kits reach out and let them know.

Send your inquiries to Kristin Ching, EPA Region 10:

• Call her at 206-900-4344 OR
• Email her at Ching.Kristin@epa.gov