Temporal changes in U.S. benzene emissions inferred from atmospheric measurements.
The 1990 Clean Air Act Amendments required the United States Environmental Protection Agency (U.S. EPA) to enact stricter regulations aimed at reducing benzene emissions. In an effort to determine whether these new regulations have been successful in reducing atmospheric benzene concentrations, we have evaluated benzene-to-acetylene ratios from data sets spanning nearlythree decades, collected during several field studies and from the U.S. EPA's Photochemical Assessment Monitoring Station (PAMS) network. The field-study data indicate a decrease in benzene relative to acetylene of approximately 40% from 1994 to 2002. This corresponds to a decrease in benzene alone of approximately 56% over the same period. In contrast, the PAMS data exhibit high interannual variability with no discernible trend. This discrepancy is attributed to measurement problems in the PAMS data sets.
Fortin
Tara J
TJ
National Oceanic and Atmospheric Administration, Aeronomy Laboratory, Boulder, Colorado 80305, USA. Tara.Fortin@noaa.gov
Howard
Benjamin J
BJ
Parrish
David D
DD
Goldan
Paul D
PD
Kuster
William C
WC
Atlas
Eliot L
EL
Harley
Robert A
RA
D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere; D001554:Benzene / Q000032:analysis*; D004784:Environmental Monitoring; D012621:Seasons; D014481:United States
D000393:Air Pollutants; D001554:Benzene