"Drywall (gypsum boards) commonly used in buildings can adsorb indoor air pollutants and release them later exposing occupants over long periods of time. Methamphetamine is a drug of abuse that contaminates building materials in many homes, including painted drywall. The objective of this study is to quantify the meth-gypsum equilibrium partition coefficient, Keq. This partition coefficient is defined as the mass of meth adsorbed per volume of gypsum per mass-concentration of gas-phase meth and has these units: (µg meth/m3 gypsum)/(µg meth/m3 air). The steady state equilibrium partition coefficient ranges from 1.1 to 3.0x105 for one drywall materials over a range of temperature (20-30⁰C) and relative humidity (19-68 %). The partition coefficient decreases as temperature and relative humidity increases while desorption rate increases as relative humidity increases. At 25⁰C and 50% RH, 4 different drywall materials exhibit a partition coefficient ranging from 1.1 to 1.8x105. Based on these results, a typical house can accumulate approximately 2g of free-base methamphetamine in drywall when equilibrated with 1ppb methamphetamine vapour in air. This is approximately 100 times the therapeutic dose for a child suffering from attention deficit hyperactivity disorder. It was estimated that more than 3 months to 6 years are required for a substantial fraction of free-base methamphetamine to be released from drywall during "airing out""--Abstract, page iii.
Civil, Architectural and Environmental Engineering
M.S. in Environmental Engineering
Missouri University of Science and Technology
ix, 70 pages
© 2014 Hongwan Li, All rights reserved.
Thesis - Open Access
Library of Congress Subject Headings
Methamphetamine -- Environmental aspects
Partition coefficient (Chemistry)
Electronic OCLC #
Li, Hongwan, "Adsorption and desorption capacity of methamphetamine in gypsum drywall" (2014). Masters Theses. 7331.