B1: Research Roundup Exposure Assessment/IAQ

Buildings are often tested for meth when there are suspicions of meth activity and are frequently found to be contaminated, but random national surveys have not been conducted to determine the actual incidence of meth contaminated houses. Many houses are occupied by non-users, often unaware of any contamination, who experience 3rd hand exposure.

We analyzed data from one survey and determined that as of 2018, 3.5% of houses in the Boulder Colorado area were contaminated at levels above health standards. We extrapolated this to the U.S. based on state meth use rates, drug manufacturing site apprehensions, meth remediations, population, and housing stock data. State-by-state estimates of contaminated houses, 3rd hand exposed persons and remediation costs were developed for the period from 1990 to 2022. The data suggest that as many as 13 million people may be occupying 5 million residences in the U.S. that are contaminated above health standards. Although based on a limited dataset, 3rd-hand meth exposure appears to be a significant environmental health issue and warrants further investigation. 

Exposure assessment to airborne methamphetamine has not been previously reported during remediation or residing in contaminated houses. Third-hand exposure occurs to occupants of contaminated residences, but the health risk assessments that have been used to set health standards assumed that inhalation exposure was insignificant, and data were not available to support or deny that assertion.

We performed air sampling in contaminated residences and preliminary results indicate that airborne meth is present. Initial results indicate a rough correlation between the surface and airborne concentrations. The airborne concentration may be significant as a part of total absorbed dose to occupants. We have also conducted exposure assessment during meth remediation. Initial results indicate that meth cleaning tasks do not result in significant exposure, but that removal of meth-contaminated contents or building materials results in some inhalation exposure, as well as dermal and ingestion.