> Research Highlight: ARL to Participate in Houston, Texas Air Study
ARL to Participate in Houston, Texas Air Study
From April 15 to May 31, 2009, the Air Resources Laboratory (ARL)
will participate in a 6-week intensive air quality study in Houston,
Texas called the Study of Houston Atmospheric Radical Precursors (SHARP)
project. Radicals are highly reactive atoms or molecules that usually
take part in chemical reactions. Radicals play an important role in
combustion, atmospheric chemistry, and many other chemical processes.
The SHARP project will include an impressive array of trace gas and
aerosol instrumentation deployed on fixed and mobile platforms to
enhance our understanding of the complex chemical and physical processes
occurring in the Houston area. ARL scientists will measure ambient air
concentrations of reactive nitrogen species (commonly referred to as
"NOx"), which are radical precursors that contribute to the formation of
ground-level ozone. ARL will also measure atmospheric mercury compounds.
Measurements will be made from rooftop laboratories installed atop the
North Moody Tower, an 18-story dormitory on the campus of the University
of Houston. ARL scientists will join dozens of other scientists and
graduate students from a wide variety of universities, private sector
companies, and other federal laboratories.
Background: The Houston metropolitan area suffers from some of the highest ground-level
ozone concentrations observed in any U.S. city. In addition, it is among
the fastest growing metropolitan areas in the country. Despite some
improvements in air quality and the reduction of emissions in recent
years, ground-level ozone violations persist. The prevalence of motor
vehicle traffic, petroleum refinery installations, and other heavy
industrial facilities contribute to a unique mix of NOx and reactive
hydrocarbon emissions in the area. This has led to the rapid and
widespread formation of ozone and other secondary air pollutants. Texas
also ranks number one among the fifty states for mercury emissions. The
SHARP project is an extension and enhancement of two earlier Texas Air
Quality Studies in 2000 and 2006 which looked at the formation and
transport of air pollutants along the Gulf Coast of southeastern Texas
and the causes of air pollution.
Significance: The SHARP project will elucidate critical emission,
chemical transformation, and deposition processes influencing the type,
amount, and spatial and temporal distributions of atmospheric radicals
ultimately responsible for the formation of ground-level ozone,
secondary aerosols, and mercury chemistry in the Houston area. Ground-
level ozone and aerosols cause respiratory and cardiovascular problems
and lead to tens of thousands of premature deaths, with costs of more
than $100 billion, each year. More than half of the people in the U.S.
live in areas that do not meet the health-based air quality standards
established by the U.S. Environmental Protection Agency. Mercury has
been detected in large concentrations around the Houston region's
petrochemical facilities. This presents the potential for enhanced local
mercury deposition to the coastal environment. Human exposure to mercury
is primarily from the consumption of contaminated fish and other aquatic
organisms. Methylmercury, a highly toxic form of mercury, adversely
affects the nervous system, particularly those of fetuses and young
children.
ARL to Participate in Houston, Texas Air Study
