Environmental Engineering Reference
In-Depth Information
2.26 Evaluation of Toxic Air Contaminants in the San
Francisco Bay Area: Regional Emissions and Ambient
Observations
Philip T. Martien
1
, David Fairley
1
, Cuong Tran
1
, Amir Fanai
1
,
Minh Nguyen
1
, Eric Stevenson
1
, Tirlochan Mangat
1
, Saffet Tanrikulu
1
,
Gary Kendall
1
, Henry Hilken
1
, Stephen B. Reid
2
, Dana C. Sullivan
2
,
Bryan M. Penfold
2
, and Eric Fujita
3
1
Bay Area Air Quality Management District, San Francisco, CA, USA
2
Sonoma Technology, Inc., Santa Rosa, CA
3
Desert Research Institute, Reno, NV, USA
1. Introduction
Emissions and concentrations of toxic air contaminants (TAC) have declined
significantly in the past decade in the San Francisco Bay Area (Bay Area), a major
metropolitan center of northern California. However, these contaminants continue
to pose serious health concerns, particularly within urban and industrialized
communities. To monitor ambient concentrations and track trends, the Bay Area
Air Quality Management District (BAAQMD) has established a TAC monitoring
network. Recently, the authors of this extended abstract have developed gridded
estimates of TAC emissions in the Bay Area and used ambient measurements and
fuel-use data to evaluate and improve these estimates. The resulting emissions
inventory was used for developing inputs for regional air quality modeling
(Martien et al., 2009) and for designing TAC mitigation measures as part of its
Community Air Risk Evaluation (CARE) program.
2. Measured Trends in Ambient TAC
The BAAQMD and the California Air Resources Board (CARB) have measured
selected toxic pollutants in the Bay Area since the late 1980s. There are no
ambient standards for these pollutants, but there are known health risks for cancer
and other acute or chronic health problems associated with them. Trends based on
TAC measurements were estimated as the ratio of means of the 2001-2005 data
with the earliest 5 years of available data.
