California Ambient Dioxin Air Monitoring Program (CADAMP) -- Overview

This page last reviewed November 10, 2010

ARB Dioxin Study
The California Ambient Dioxin Air Monitoring Program (CADAMP) was administered by the Air Resources Board to provide information on ambient levels of dioxins and dioxin-like compounds. CADAMP was modeled, in part, after the U.S. Environmental Protection Agency's (U.S. EPA) National Dioxin Air Monitoring Network (NDAMN) to ensure the data from the two networks can be used interchangeably.  The CADAMP used the same sampling and analytical techniques as NDAMN. However, the ARB ambient monitoring program had an urban focus and emphasized sampling for ambient dioxin levels in populated areas. The NDAMN program focused its nationwide sampling network in rural areas to study the critical pathways by which dioxins enter the food chain.

Twelve sampling sites were deployed in CADAMP, five in the San Francisco Bay Area, four in the South Coast Air Basin, one in Sacramento, and two in Fresno County. Samples were collected weekly. However, in order to achieve the low limits of detection needed for ambient dioxins, furans, PCBs, and PBDEs, the four weekly samples obtained each month were extracted as one monthly sample. The data was compiled as monthly and annual averages to help understand seasonal and long-term exposure. The local air quality management districts were important partners in the operation of the samplers and in installing and retrieving the filters and polyurethane foam (PUF) sampling media. A laboratory under contract to ARB conducted analyses and achieved the lowest detection limits possible. High resolution gas chromatography/high resolution mass spectrometry (HRGC / HRMS) assays were performed to detect ambient concentrations as low as 1 fg/m3 (femtogram per cubic meter) of sampled air.

National Dioxin Study
The U.S. EPA conducted ambient dioxin, furan, and polychlorinated biphenyls (PCB) analyses in rural areas of the country as part of the National Dioxin Air Monitoring Network (NDAMN). The NDAMN protocol used high volume samplers to measure background atmospheric levels at approximately 31 rural sites around the country. The specific NDAMN target monitoring locations included agricultural areas where livestock, poultry, and animal feed crops are grown to provide data to evaluate results from long-range transport and deposition air models. Fort Cronkhite and Rancho Seco were the NDAMN sites in California. Operation at these sites began in December 2000 and June 2001, respectively, using resources from the Bay Area Air Quality Management District (BAAQMD), the U.S. EPA, and SMUD (Sacramento Municipal Utility District). The Fort Cronkhite sampler was located on the Marin County coastal headlands and provided valuable information on the influx of dioxin-like compounds into California. The Rancho Seco site was a California rural site.

For additional dioxin exposure initiative publications, please go to http:/

For further information contact:
Jeff Wright, Manager, Operations Planning and Assessment Section
Kathy Gill, Manager, Organic Laboratory Section