(VCCEP) Tier 1 Pilot Submission for BENZENE - Tera

Benzene VCCEP Submission
March 2006
Figure 5.2
From htttp://www.epa.gov/airtrends/toxic.html (accessed 7/1/03)
Significant decreases have also been seen at the state level. In both the state of California and
in the Houston-Galveston, Texas area, the decrease in benzene from 1989 to 2001 was 79%
(U.S. EPA, 1996; URS, 2002). Additionally, a study in Camden, New Jersey measured a 58%
decrease in ambient benzene air concentrations from 1990 to 1997 (Weisel, 2002).
This drop in ambient benzene concentrations is largely a result of the decrease in mobile source
emissions due to fleet turnover, Tier 1 car emission standards, and use of reformulated gasoline
in many cities. Additionally, voluntary emissions reductions and the implementation of the
maximum achievable control technology (MACT) and other federal, state and local regulations
for the petroleum and chemical processing industries have brought about a decrease in
benzene emissions from stationary sources.
Besides the reduction of VOCs and benzene specifically, there has also been a reduction of
sulfur in gasoline. Lower sulfur content increases catalytic converter efficiency, thus decreasing
hydrocarbon emissions, including benzene.
As indicated in Section 4, a number of regulatory actions aimed at reducing benzene emissions
have been initiated or are scheduled to occur in the next 10 years. These regulations and the
turnover of older cars will result in a continued reduction of benzene emissions. This downward
trend has two implications. First, motor vehicles are major contributors to outdoor urban air
levels, vehicle related exposures, and to indoor air levels (for homes with attached garages).
Thus, in considering the ambient outside and indoor air exposure pathways exposure studies
from the 1980s and 1990s are likely to be overestimates of the current exposures. Second,
future benzene exposure from these sources are likely to be lower than current levels.
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