December 2006
Mercury Release In Homes with Pressure Regulators
Our Challenge
- Elemental mercury (of quantities of 3 to 10 milliliters) can be found in the gas pressure regulators of many homes built between 1935 to 1975. Consequently, over the last 25 years small mercury spills have occurred during installation and removal of these units (usually in the basement).
- We were asked to measure airborne mercury levels at known and possible spill locations and to evaluate their public health implications.
Our Approach
- ChemRisk created a field program to measure airborne mercury concentrations (within the range of 0.1 to 5.0 µg/m³) at sites located in Michigan and Illinois.
- We collected airborne mercury samples at 1000 homes.
- Phase I: homes where a known prior release and cleanup of mercury occurred.
- Phase II: homes were a regulator may have been removed.
Our Findings
- For the Phase I homes, average airborne concentrations of mercury in home basements were below the Agency for Toxic Substances and Disease Registry (ATSDR) residential action level of 1.0 mg/m³.
- For Phase II homes, a spill may occurred in a small number of the homes. However, the average airborne concentrations in the basement of homes were almost all less than 1.0 mg/m³.
- Overall, mercury speills occurred in 0.7% of all homes where regulators had been removed.
- Data were presented at both SOT and SRA meeting as “Elemental mercury releases associated with the removal of gas pressure regulators in homes”.