Proof that residents of Northport, WA have been chronically exposed to heavy metal toxins from Teck smelter’s air

Based on all the historical data, regulatory benchmarks, and EPA risk frameworks reviewed, the answer is yes—residents of Northport, WA have been chronically exposed to levels of arsenic, cadmium, and lead in ambient air that exceed established health risk thresholds, particularly during the years covered by Teck’s emissions monitoring (1993–2009).

Key Points That Support This Conclusion

Chronic Exposure Levels Exceeded Risk Benchmarks:

These levels were documented in air monitoring at Sheep Creek and Teck-Cominco stations and reflect long-term,  consistent exceedances of public health benchmarks.  

Washington’s ASIL Thresholds Were Also Violate:  

• Arsenic ASIL: 0.00023 µg/m³  
  • Northport air levels were more than 100× higher

• Cadmium ASIL: 0.00056 µg/m³  
  • Air levels exceeded this by nearly 20×.  

Duration and Population Sensitivity Matter:  

These exposures occurred over decades, affecting:  

• Children, who are particularly vulnerable to lead neurotoxicity.  
• Pregnant women, due to lead and cadmium effects on fetal development.
• The general public, due to arsenic’s cancer-causing potential via inhalation.  

EPA’s 2021 HHRA Missed the Air Pathway

While EPA’s Human Health Risk Assessment in 2021 stated that air exposure did not present significant health risk, this was based on outdated air data (pre-2009) and modeling assumptions, not new measurements. Even so, EPA’s own values (RSCs/RfCs) suggest levels measured before 2009 should trigger public health concern.

Conclusion

There is a strong public health rationale to conclude that Northport residents faced (and may still face) an elevated risk from chronic exposure to airborne arsenic, cadmium, and lead. The levels recorded in monitoring significantly surpass both federal and state thresholds for safe chronic exposure—particularly for sensitive populations and over extended periods.

This reinforces the need for:

• Updated ambient air monitoring in Northport and the river valley.

• Medical biomonitoring of residents.

• Longitudinal health studies.

• Regulatory accountability for cross-border industrial emission