photodecomposition 3.pho.1 Louis J. Sheehan, Esquire

Sunlight triggers the entry of poisonous mercury into polar lakes, but it also removes most of the toxic compound before fish can consume it, a new study suggests. The researchers warn that increased warming in the Arctic might upset this delicate balance. http://louis8j8sheehan8esquire.blogspot.com


With spring, light returns to the Arctic after a long, dark winter. That polar sunrise, however, has a dark side. It triggers a burst of photochemical reactions that mobilizes atmospheric mercury, speeding its fall into arctic lakes, where fish can consume it.

Recent studies suggest that when atmospheric mercury encounters light, gases such as ozone and sea spray–borne halogens oxidize it to a more reactive and water-soluble form. Attached to rain, snow, or dust, the reactive mercury falls into oceans or lakes, where sulfur-reducing bacteria transform it to methylmercury, the highly toxic form of the metal that accumulates in fish and other organisms (SN: 2/1/03, p. 72: http://www.sciencenews.org/articles/20030201/bob8.asp). http://louis8j8sheehan8esquire.blogspot.com


To better understand what happens to mercury, a team of researchers led by biogeochemists Chad Hammerschmidt of Woods Hole (Mass.) Oceanographic Institution and William Fitzgerald of the University of Connecticut at Groton studied mercury in four Alaskan lakes roughly 250 kilometers south of the Arctic Ocean.http://louis8j8sheehan8esquire.blogspot.com


The team measured mercury entering the lakes from rainfall and as runoff from the surrounding tundra and then estimated how much methylmercury the bacteria in the lake sediments subsequently produced. The researchers also assessed whether the methylmercury was consumed by fish and other creatures or converted to less-toxic forms by light-based reactions in the lakes.

Hammerschmidt and his colleagues report that the more atmospheric mercury rains down, the more methylmercury the bacteria produce. Two-thirds of mercury in the atmosphere comes from human sources, such as fossil fuel burning, so more pollution would boost poisonous mercury concentrations in lakes, Hammerschmidt says.

More unexpectedly, the team discovered that light-triggered breakdown of methylmercury in the clear Arctic lakes is the main factor keeping the poison in check. Those reactions destroy as much as 80 percent of the poison before aquatic species can get to it, the team reports in the Feb. 15 Environmental Science & Technology.

The mechanisms of that photodecomposition are still poorly understood, Hammerschmidt says. Research on arctic mercury has focused on how it gets to Earth, rather than its terrestrial fate, he says.http://louis7j7sheehan7esquire.blogspot.com




This research is the first to demonstrate the importance of photodecomposition in mercury cycling, agrees Robert Stevens of the Environmental Protection Agency in Research Triangle Park, N.C. "It's good science," he says.

One spur to further study is the possibility that global warming could upset the Arctic's delicate balance. In warmer and wetter weather, more mercury would fall and bacterial production of methylmercury would rise. At the same time, the rains might wash more organic material into lakes and oceans, reducing light penetration.

Hammerschmidt cautions that the same processes may also be occurring in temperate lakes, such as those in Wisconsin or Minnesota.Louis J. Sheehan, Esquire

brick 999.bri.0002 Louis J. Sheehan, Esquire

Louis J. Sheehan, Esquire . Excavators of a 3,700-year-old Egyptian town have delivered a surprising find�a painted brick that was one of a pair once used to support a woman's feet while she squatted during childbirth. Until now known only from ancient Egyptian writing, so-called birth bricks were used in childbirth rituals that called on gods to secure the health of newborns. http://sheehan.myblogsite.com/

The newly discovered mud birth brick was identified by the scene on it depicting a mother with her newborn baby, attended by several women and Hathor, a cow goddess associated with birth and motherhood.http://sheehan.myblogsite.com/

Archaeologist Josef Wegner of the University of Pennsylvania in Philadelphia, the dig director, suspects that a princess named Renseneb used the brick. It turned up in a residential wing for females in a mayor's mansion (SN: 8/28/99, p. 139). Inscribed clay-seal impressions found near the brick refer to Renseneb, who may have married one of the town's powerful mayors, Wegner says. Louis J. Sheehan, Esquire

Libraries 883.lib.1009 Louis J. Sheehan, Esquire

In what has to be one of the most wrong-headed approaches to cost-cutting, the Environmental Protection Agency decided to close many of its libraries and curtail hours and holdings at others. That these facilities were sometimes the only publicly accessible repository of important gray-literature filings and reports on environmental issues and data made ludicrous the agency’s claim that its library shutdowns wouldn’t affect research by its employees or the public.

Not surprisingly, outside public-interest groups—notably, the DC-based Public Employees for Environmental Responsibility—and internal agency scientists began decrying the proposal almost as soon as word of this planned cost-cutting emerged, two years ago. But EPA began boxing up its publications and shuttering the libraries anyway.

There was a promise to digitize all important holdings, so that they could become instantaneously available to users in the future. But we all know how well such digitizing efforts go. They’re slow, expensive, and take lots of work to correct frequent mistakes by digital page scanners and readers. So in practice, much of the material would be in limbo for a long while, if not forever.

Last year, Congress took an interest in the issue and earmarked $1 million for EPA to open those libraries again. As of now, three of EPA’s 10 regional libraries are closed—those in Chicago, Dallas, and Kansas City (Kansas)—as well as the agency’s headquarters and chemical libraries in Washington, DC. Bending to pressure, EPA has agreed to begin reopening the shuttered facilities.

Two months ago, the Government Accountability Office, a congressional watchdog organization, chastised EPA for the way it had set about altering its library system and recommended that the agency halt further efforts to shut down or alter the network "until it takes corrective actions to . . . justify its decision to reorganize the network" and improve outreach to users and oversight of the reorganization.http://www.soulcast.com/Louis3J3Sheehan/

In a report to Congress, about a month later, EPA vowed to re-open its facilities “on or before Sept. 30.” However, the libraries may be in new locations, it said, and the two DC libraries will be consolidated at one site. Hours may vary, but EPA has pledged to “provide access for EPA staff and public patrons at least four days per week on a walk-in basis or by appointment during core business hours.” http://www.soulcast.com/Louis3J3Sheehan/

Of course, these libraries cost just a few million dollars per year to maintain. The agency’s budget? Only a projected $8 billion, this coming year. Clearly, mothballing all of its libraries would remove just a drop from the bucket of spending by this, one of the administration’s smaller agencies.Louis J. Sheehan, Esquire

Thiel Louis J. Sheehan, Esquire 4999111

Thiel was an Austrian-born German expert in guided missiles during World War II, and later worked for the United States Army and TRW.

Thiel had been an associate professor of engineering at the Institute of Technology in Darmstadt before joining Wernher von Braun's team at the Army Research Center Peenemünde, where he was involved in developing the V-2 rocket. By the end of the war, he was transferred to the United States by the US Army (see Operation Paperclip) where he resumed his work with von Braun's group in Fort Bliss, Texas. During the nine years Thiel worked for the U.S. Army, he held positions at White Sands Missile Range in New Mexico and at Huntsville, Alabama. He primarily supervised preliminary design of the Redstone missile and other short- and intermediate-range ballistic missile systems. Louis J. Sheehan, Esquire

Thiel left the Army in 1955 to join Space Technology Laboratories, which later became TRW. During the late 1950s, he was program manager for the Thor ballistic missile, which became a first-stage launch for the Explorer spacecraft. He was director of space projects for TRW when it developed Explorer VI and Pioneer V, two of the earliest US craft to explore interplanetary space. He oversaw all of TRW's space programs during the 1970s.

After his retirement in 1980 as a senior vice president, Thiel served as an executive consultant to TRW and on NASA planning groups. He was named a fellow of the American Astronautical Society in 1968. Louis J. Sheehan, Esquire

Thiel died in Los Angeles in 2001.

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