摘要:Naphthalene, a constituent of coal tar, is a contaminant frequently found at former manufactured gas plants (MGP). Development at these sites has resulted in residential and commercial areas with potential exposures from vapor intrusion adversely affecting indoor air of residences and buildings. Naphthalene is routinely analyzed in soil vapor intrusion assessments for properties overlying and surrounding former MGP sites. The United States Environmental Protection Agency (EPA) has a proposed unit risk factor and the State of California has promulgated a unit risk factor for naphthalene. Naphthalene exposure from vapor intrusion is potentially a public health risk. The purpose of this study was to evaluate three sites located in the northeast United States to determine the frequency of naphthalene detection in indoor air. A total of 79 properties were included in the study. A total of 546 indoor air samples were analyzed for naphthalene on 161 occasions. Naphthalene concentrations ranged from 0.26 to 51 μg/m3 of air. Only 3 of the 546 indoor air samples detected naphthalene above the ninety-fifth percentile background value of 12 μg/m3 of air. Risk analysis indicated naphthalene vapor intrusion was not a public health risk among the 79 properties built on or near the former MGP sites.