Chemicals

Chemical Exposures at Naval Air Facility Atsugi

During the operation of the Shinkampo incinerator complex, the Department of the Navy conducted extensive environmental sampling and health risk assessments to evaluate potential exposures affecting the base population. These efforts included:

  • Multiple air and soil sampling campaigns (1988 to 2001)

  • Two screening human health risk assessments (1995, 1998)

  • A comprehensive human health risk assessment (2002)

The 2002 assessment alone identified approximately 269 chemicals in ambient air, with 44 designated as “contaminants of concern” (COCs) due to concentrations exceeding EPA risk-based benchmarks and regulatory standards. Earlier studies also documented exceedances across multiple environmental media, including air, soil, and water

Contaminants of Concern by Study

Here are the lists of contaminants of concern identified at the time of each study:

VFEA Cross-Study Analysis

The list of 44 “contaminants of concern” for ambient air is no longer current as the final health risk assessment was published in June 2002—more than 24 years ago—and relied on scientific assumptions, toxicity values, exposure factors, and analytical methods developed primarily in the 1980s and 1990s. Since that time, there have been substantial advances in toxicological science and exposure assessment, as well as a more refined understanding of the long-term and cumulative health effects associated with incinerator-related contaminants such as dioxins, metals, particulate matter, and other combustion byproducts. If the 2002 health risk assessment were to be updated today there would be more than 44 contaminants of concern.

Ultimately, the Navy should conduct an updated health risk assessment that also incorporates current risk assessment methodologies and toxicity data to provide a more accurate and complete evaluation of potential exposures.

In the iterim, VFEA reviewed all available environmental sampling data and compared the maximum detected concentrations of each chemical to current EPA health-protective benchmarks, including Regional Screening Levels (RSLs) for residential air and National Ambient Air Quality Standards (NAAQS), to develop a more comprehensive list of contaminants of concern using updated toxicological data.

  • Between all sampling efforts, approximately 288 chemicals were detected in the ambient air and soil.

  • At least 55 “contaminants of concern” were identified in the ambient air