On March 3, 2021, Portland Fire/Hazmat notified EPA of a residential mercury spill at a single family residence in northeast Portland, Oregon, and requested EPA's assistance in conducting a site assessment and screening for mercury contamination. Portland Fire/Hazmat reported that one of the residents had accidentally dropped a thermometer onto a bathroom floor and into the bathroom heating duct during the early morning hours that same day.
An EPA OSC responded to the site along with the Portland Fire / Hazmat Team Coordinator, and conducted a site assessment and screening for mercury contamination throughout the house. The assessment and air monitoring showed mercury contamination was mostly limited to the downstairs bathroom, which had elevated levels of mercury vapor (well above 1,000 ng/m3). A small trash can outside the bathroom also showed elevated levels of mercury, but the garbage inside the can was bagged up by EPA and disposed. However, air monitoring throughout the rest of the home showed very low levels of mercury vapor.
After discussion with a health toxicologist from the Agency for Toxic Substances and Disease Registry (ATSDR), it was determined that the residents could stay in the home if the heating system was not used and the bathroom isolated and sealed up. The residents were then informed of the results and advised not to enter the bathroom nor their HVAC system until cleanup could occur. The residents then moved back into their home.
On March 6, the homeowners hired and mobilized a qualified hazmat cleanup contractor to the site to conduct the mercury cleanup. The contractor (NWFF) conducted a a mercury removal and cleanup of the bathroom floor and vent area and sealed the area off for 8 hours. Also on March 6, EPA returned to conduct an assessment of the removal, and conducted air monitoring of the bathroom post cleanup. All mercury vapor levels were found to be well below ATSDR guidance levels for re-occupation.
