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.

comments powered by Disqus