In the Lab
Study: Invisible Gases Form
Most Organic Haze
Invisible, reactive gases hovering over
Earth’s surface, instead of direct emissions
of particulates, form the bulk of
organic haze in urban and rural areas
around the world, according to a University
of Colorado at Boulder study.
Many science and health professionals
originally believed sources that spew soot
and other tiny particles directly into the
air were the primary culprit in the formation
of organic haze. However, a study by
researchers at CU-Boulder’s Cooperative
Institute for Research in Environmental
Sciences (CIRES) shows aerosols formed
chemically in the air account for about
two-thirds of the total organic haze in
urban areas and more than 90 percent of
organic haze in rural areas.
The study was led by Qi Zhang, a former
CIRES scientist now at the Atmospheric
Sciences Research Center at State
University of New York, Albany and
CIRES researcher Jose-Luis Jimenez. The
study was published in the July 7 online
issue of Geophysical Research Letters.
The scientists compared concentrations
of directly emitted or primary
aerosols with chemically formed or secondary
aerosols. They surveyed urban
areas, areas downwind of urban areas,
and rural areas from 37 sites in 11
countries.
“What we’re seeing is that concentrations
of secondary organic aerosols
decrease little downwind from urban
areas,” said Jimenez, also an assistant
professor in CU-Boulder’s chemistry and
biochemistry department. “That tells us
there has to be an extended source or
continuous formation for the pollution.”
The scientists believe the extended
source of particle pollution is reactive,
colorless gases called volatile organic
compounds (VOCs), the same gases that
form smog. Jimenez said he believes
VOCs emitted in urban and regional
areas immediately begin undergoing a
chemical transformation that causes
them to stick to particles and increase
such pollution.
“We think the gases react over a few
days as the air travels downwind into
more rural regions, producing more
organic haze,” he said.
Reactive gases are a diverse group of
chemical compounds that include VOCs,
surface ozone, nitrogen compounds, and
sulfur dioxide. All play a major role in
the chemistry of the atmosphere and as
such are heavily involved in interrelations
between atmospheric chemistry
and climate.
VOCs are released by cars and trucks,
gasoline evaporation that occurs during
gas station fill-ups, and some industrial
processes, said Zhang. VOCs also are
produced naturally by vegetation.
The U.S. Environmental Protection
Agency (EPA) does not currently regulate
VOCs except for on-road vehicles
and industrial settings.
Jimenez and Zhang are working to
better understand the importance of
natural and human sources of VOCs in
the production of secondary organic
aerosol pollution, including which
human sources significantly contribute
to the problem.
“One question is whether we could
improve air quality if we directly targeted
VOC emissions and not just particle
emissions,” said Zhang. “Until we understand
the breakdown between humancaused
and natural VOC emissions, and
between different human sources, we
won’t have an answer to that question.”
The study was funded by EPA, the
National Science Foundation, and
NASA. For more information, visit
www.colorado.edu/news/releases/
2007/261.html.
New Era in Recycling Plastics
Scientists in Japan are reporting development
of a process that breaks certain
plastics down into their original chemical
ingredients which can then be reused
to make new, high-quality plastic.
This approach fostered recycling of
beverage cans, scrap steel, and glass
containers that are melted to produce
aluminum, glass, and steel. However, no
process has emerged to depolymerize the
long chains of molecules that make up
millions of pounds of polymer, or plastic,
materials that are trashed each year.
Instead, recycling of certain plastics
involves melting and reforming into
plastic that is less pure than the original.
In a June 25 announcement by the
American Chemical Society (ACS), Akio
Kamimura and Shigehiro Yamamoto
reported invention of an efficient new
method to depolymerize polyamide plastics
— which include nylon and Kevlar
— in an article in ACS Organic Letters.
The technology, still at the laboratoryscale
stage, does not require costly pressure
chambers, extreme temperatures,
or high-energy inputs. Rather, it uses
ordinary laboratory glassware.
The method relies on ionic liquids,
which are powerful solvents.
Researchers used an ionic liquid that
changed nylon-6 into its component
compound, captrolactam, and could be
recycled and reused multiple times.
“This is the first example of the use of
ionic liquids for effective depolymerization
of polymeric materials and will
open a new field in ionic liquid chemistry
as well as plastic recycling,” the
report states.
The report, “An Efficient Method to
Depolymerize Polyamide Plastics: A New
Use of Ionic Liquids, can be found at
http://pubs.acs.org/cgibin/
sample.cgi/orlef7/2007/9/i13/html
/ol070886c.html.
Ten Penguin Species Added to
Endangered Species List
Protection under the Endangered
Species Act (ESA) may be warranted for
10 species of penguins found in Antarctica
and the southern hemisphere, the
U.S. Fish and Wildlife Service (USFS)
announced in July. The USFS will conduct
a full review of the 10 species’ status
and determine whether to propose
them for inclusion on the Federal List of
Endangered and Threatened Wildlife
and Plants.
The penguin species inhabit areas of
Antarctica, Argentina, Australian Territory
Islands, Chile, French Territory
Islands, Namibia, New Zealand, Peru,
South Africa, and United Kingdom Territory
Islands. Threats to the species
include commercial fishing, competition
for prey, habitat loss, danger from nonnative
predators, contaminants, pollution,
and impacts to the marine and terrestrial
environment brought on by climate
change.
An initial finding by USFS responded
to a petition that requested 12 penguin
species be listed under the Endangered
Species Act. The initial review, called a
90-day finding under the act, found substantial
information indicating that listing
may be warranted for only 10 of
those species.
Listing these penguin species under
the domestic Endangered Species Act
would provide limited and indirect protection,
since no penguins are native to
the United States. A listing would make
it illegal to engage in certain activities
such as the import or export of specimens
of these species without an ESA
permit, which is issued only if an activity
has a conservation benefit. Listing
would also focus international attention
on the species’ conservation needs.
The 10 penguin species for which the
USFS found substantial information
indicating that listing may be warranted
include the emperor penguin (Aptenodytes
forsteri), southern rockhopper
penguin (Eudyptes chrysocome), northern
rockhopper penguin (Eudyptes moseleyi)
(E. chrysocome moseleyi)), fiordland
crested penguin (Eudyptes
pachyrhynchus), erect-crested penguin
(Eudyptes sclateri), macaroni penguin
(Eudyptes chrysolophus), white-flippered
penguin (Eudyptula albosignata (E. minor
albosignata)), yellow-eyed penguin
(Megadyptes antipodes), African penguin
(Spheniscus demersus), and Humboldt
penguin (Spheniscus humboldti).
The petition did not contain substantial
information to indicate that a listing
may be warranted for snares crested
penguin (Eudyptes robustus) and royal
penguin (Eudyptes schlegeli).
During the status review, the USFS
will study scientific literature and contact
experts on penguin biology and
other relevant areas. A 60-day comment
period opened on July 11, 2007 to solicit
scientific and commercial information
from the public regarding these species.
Comments in writing may be e-mailed
to DSApenguins@fws.gov or through
the Federal eRulemaking portal. A link to the Federal
Register notice of the 90-day finding
may be found at
www.fws.gov/international.
This article originally appeared in the 09/01/2007 issue of Environmental Protection.