The objectives of this project were to evaluate ELISA screening methods and determine whether these methods indicate effectively those microenvironments where high exposure to polycyclic aromatic hydrocarbons (PAH) or other semivolatile organic compounds (SVOC) is likely. The dust/soil samples as well as sample extracts of air and food samples collected from 13 low-income homes in the summer of 1995 were analyzed by PAH and C-PAH assays. These sample extracts were also analyzed by gas chromatography/mass spectrometry (GM/MS) to determine alkyl PAH and phthalates. The dust/soil samples from 13 low-income homes collected during the spring of 1996 were analyzed by PAH C-PAH, 2,4-D, and PCP assays. Different aliquots of these samples were analyzed by conventional (GC/MS) methods for PAH and by GC with electron capture detection (GC/ECD) for 2,4-D and PCP. The ELISA data were compared with GM/MS data or GC/ECD data. For PAH measurements, there is no strong relationship between the ELISA results and GC/MS results when data of similar types of samples were combined from different field studies. The ELISA data (C-PAH) and GC/MS (B2 PAH) data showed stronger relationships for dust/soil collected from 22 NHEXAS homes. The ELISA screening for PAH can indicate the likely presence of high levels of PAH in dust/soil samples. There is a positive but weak relationship between GC/ECD data and ELISA data for 2,4-D and PCP.