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Levels of dioxin-like compounds (DLCs) appear to have declined in chickens, hogs and turkeys produced for food in the United States, according to new tests conducted by the U. S. Department of Agriculture. Levels measured in 2002-2003 were 20 percent to 80 percent lower than levels measured in less extensive testing done from 1994-1996, according to study results, which are scheduled for publication in the Aug. 15 issue of the ACS Environmental Science and Technology. However, researchers could not determine with certainty whether DLC levels in cattle changed over that period.
In the article, Cynthia L. Deyrup and colleagues report results of a survey of DLC levels in the four slaughter classes that represent about 90 percent of meat and poultry production in the United States. None of the chickens or turkeys and only 5 of 139 cattle and 3 of 136 hogs exceeded existing regulatory limits on dioxins, which have been adopted in the European Union. The report also discusses the possible sources of DLCs in animals with higher levels of DLCs.
DLCs are a family of compounds that enter the environment as byproducts of combustion and certain manufacturing processes. DLCs accumulate in the fat of humans and animals. One DLC has been classified as a “known human carcinogen.” However, controversy continues over the strength of the scientific evidence about human health effects from DLCs, the report notes.
Journal: Environmental Science and Technology
Journal Article: "Statistically Designed Survey of Polychlorinated Dibenzo-p-Dioxins, Polychlorinated Dibenzofurans, and Co-Planar Polychlorinated Biphenyls in U. S. Meat and Poultry, 2002-2003: Results Trends, and Implications"
Erasable graffiti? Imagine writing “Happy Birthday Mom!” in flamingo pink letters three-feet high on the front lawn or the side of the house. Then imagine washing them away easily when the party is over.
D. Tyler McQuade and Muris Kobaslija report development of a new family of removable colored coatings that could make such temporary messages feasible. In a study scheduled for the Aug. 14 issue of the ACS journal, Biomacromolecules, they describe development of a nontoxic, biodegradable coating using calcium alginate and dyes that are widely used as food colorants. Calcium alginate is a firm, clear, quick-setting gel used in food thickeners and coatings, microcapsules for drug delivery and other products.
The new material adheres to surfaces easily and firmly, remaining intact when sprayed with a jet of water. However, it comes right off when treated with a non-toxic water solution. “Temporary field lines and logos for sports complexes and roadway markings, as well as coatings for plants, fruit and the body are just a few examples that underscore where removable coatings could be applied,” the researchers said in the paper.
Researchers report the first detailed results of electric power generation with a new technique that could drive implantable medical devices, sensors and portable electronics without the need for bulky batteries or other energy sources. Instead of batteries, electricity for such devices would come, for instance, from muscle contraction or other body movements, according to Zhong Lin Wang and colleagues.
Their report, scheduled for the Aug. 9 issue of the ACS journal Nano Letters, describes experimental observation of electric power production with “nanogenerators” fashioned from a single zinc oxide nanowire and a nanowire belt. In earlier research, Wang's group discovered that zinc oxide nanowires produce electricity via a long-known phenomenon termed the pizoelectric effect. It occurs in certain materials, which change mechanical energy — from flexing or twisting, for instance — into electricity.
“The methodology and applications demonstrated in this paper simply open a new field in nanotechnology,” the researchers report. In summarizing implications of the new findings, they cite potential harvesting of electricity from mechanical movement energy (such as body movement, muscle stretching and blood pressure), vibration energy (sound waves) and hydraulic energy (blood flow or contraction of blood vessels). The technology might be used in wireless self-powered nanodevices, to charge battery-powered devices and in building larger-scale electric power generators, they add.
Journal: Nano Letters
Journal Article: "Pizoelectric and Semiconducting Coupled Power Generating Process of a Single ZnO Belt/Wire: A Technology for Harvesting Electricity From the Environment "
Scientists now can identify strategies for reducing levels of acrylamide formed when starchy foods are baked, roasted, fried or toasted, according to an article scheduled for the Aug. 14 issue of Chemical & Engineering News, the American Chemical Society’s weekly newsmagazine.
Those first roadmaps for responding to concerns about acrylamide — a neurotoxin and probable human carcinogen — have emerged from a flurry of scientific research done on the compound since 2002, writes C&EN Senior Editor Bette Hileman. The studies began after acrylamide was first identified in food; about 200 scientific papers on the compounds now have been published.
However, the research provides few answers about acrylamide’s human health risks, C&EN says. The article discusses how food authorities in the United States and Europe have taken different approaches to regulating acrylamide levels in food. The highest levels occur in French fries and potato chips.
Efforts to reduce acrylamide in food in the United States may depend on the fate of a proposed Federal law, according to the C&EN article. The law would restrict state efforts to regulate acrylamide and other food compounds more stringently than does the U.S. Food and Drug Administration.
Many reporters who cover chemistry, materials science, medicine, health, environment and business closely follow the rapid-pace of innovation in nanotechnology.
The American Chemical Society Office of Communications is offering reporters who attend the American Chemical Society national meeting in San Francisco or who work in the area an opportunity to visit nanotech labs in the Bay area.
September 10-14 is one of the year’s biggest and most influential scientific conferences – the 232nd ACS national meeting in beautiful San Francisco.
The American Chemical Society – the world’s largest scientific society – is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
Journal: Chemical & Engineering News
Journal Article: “No Quick Fix for Acrylamide in Food: Intense scrutiny has provided methods of reduction but few answers about risk”