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October 04, 2010

NanoTitania Problems

NANOTITANIA MAY DISRUPT AQUATIC ECOSYSTEMS' NITROGEN CYCLE: Products coated in titanium dioxide nanoparticles (nTiO2) shine pure white. So since the 1990s manufacturers have added the chemicals to a wide range of consumer products, such as cosmetics, paints, sunscreens, and even foods. Now nTiO2 often discharges into open waterways through treated sewage effluent. A new study reports that this nanomaterial can stress photosynthetic organisms, which could lead to the disruption of nitrogen and carbon cycles in aquatic ecosystems (Environ. Sci. Technol., DOI: 10.1021/es101658p).


GROWING PROBLEM: Before (left) and after (right) images of A. variabilis cells exposed to TiO2 nanoparticles show the growth of cyanophycin grana protein granules (dark spots).

Most research on the toxicity of nTiO2 has focused on the chemical's potential human health effects rather than on its environmental impact when it reaches rivers and lakes. So environmental engineers April Gu and Carla Cherchi of Northeastern University in Boston wanted to study how the nanomaterial affects a model organism from an aquatic ecosystem. The researchers picked Anabaena variabilis -- a common cyanobacteria, sometimes called blue-green algae -- because the bacteria undergoes photosynthesis and nitrogen fixation. "It represents a crucial step in both the nitrogen and carbon cycles," Gu says. Gu and Cherchi grew cultures of the cyanobacteria with varying amounts of suspended nTiO2. To evaluate the nanoparticles' effects, the researchers monitored changes in cell growth and cell structures, such as production of cyanophycin grana protein (CGP) granules. Previous studies have shown that organisms synthesize this nitrogen-rich protein during environmental stress as a means to store nitrogen. At nTiO2 levels similar to those found in wastewater effluent, A. variabilis growth dropped by 90%. The researchers also observed that CGP granule size increased with both greater nanoparticle concentration and exposure time. When exposed to high levels of nTiO2, CGP granules occupied greater than 16% of the cell's cross-sectional area within 96 hours, compared to less than 1% for controls. Both observations suggest nTiO2 could disrupt an aquatic ecosystem's carbon and nitrogen cycles, the researchers conclude. During times of slowed cell growth, photosynthesis grinds to a halt and the cell's carbon dioxide intake drops. Meanwhile, synthesizing CGP granules shifts fixed nitrogen away from production of inorganic nitrogen compounds, which the bacteria normally excrete into the environment. By documenting the effects of nTiO2 on aquatic ecosystems, the study fills an important data gap in nanomaterial toxicology, says Anne Kahru of the National Institute of Chemical Physics and Biophysics in Estonia. She also points out that nTiO2 toxicity could have a potential application: Water purification processes based on nTiO2 could limit growth of cyanobacteria in closed water systems, such as cooling towers and boilers. Chemical & Engineering News, 04 October 2010, online.

December 27, 2009

All About Bishenol-A

ASSESSING RISKS FROM BISPHENOL-A: The industrialized world produces an immense amount of plastic, more than 45 billion kilograms annually in the United States alone. But what is it made of, and is it all safe? Some reusable water bottles sold in Wal-Mart and other retail stores in the United States now display stickers proudly marketing themselves as "BPA-free." The labeling results from consumer concern over scientific evidence that bisphenol A (BPA), a common ingredient in many hard plastics, may be harmful to the human reproductive system because it interferes with hormones. The plastics industry and the U.S. Food and Drug Administration (FDA) say BPA is not dangerous at the levels people are currently exposed to. In contrast, in September of 2008, the U.S. National Toxicology Program (NTP) concluded that there is "some concern" for adverse effects on the "brain, behavior and prostate gland in fetuses, infants, and children." This concern prompted members of Congress to pressure the FDA to take another look, a process that is now underway.


A factory worker in England lifts a reusable water container manufactured, in part, with bisphenol A (BPA), a chemical used to make polycarbonate plastics and epoxy resins. BPA is an endocrine disruptor, meaning it is capable of interfering with normal hormone functioning in organisms. Evidence is mounting that BPA exposure can disrupt normal reproductive-system development and functioning in laboratory animals. There is a pressing need to overcome challenges to assessing the true risks that this compound -- and the many others like it—pose for people.

Inconsistent messages about BPA safety have generated considerable public rancor, highlighting how human risk assessment of BPA (and compounds like it) is both uncoordinated and controversial. Consensus regarding BPA's safety has evaded U.S. health agencies for multiple reasons. Most pressing is the lack of clear guidelines for how much or what type of scientific evidence is needed to judge risks from hormone-disrupting compounds such as BPA. It would be unethical to directly assess those risks in people through controlled, double-blinded exposure experiments. At the same time, there are uncertainties about when exposure data from animal studies are relevant to human health. In a global environment where BPA production and exposure have grown rapidly, there is a pressing need to overcome these challenges. That is especially true because BPA is only one of thousands of chemicals thought to possibly have unintended effects on reproductive health. For the complete article, please click on to http://www.americanscientist.org/issues/feature/2010/1/assessing-risks-from-bisphenol-s/1. American Scientist, January-February 2010, pp. 30-39.

December 12, 2009

EPA's Proposed Greenhouse Gas Emission Redution Rules

PROGRESS ON CLIMATE RULES HEIGHTENS INDUSTRY CONCERN: Chemical companies in the U.S. are increasingly concerned about EPA's progress toward mandating greenhouse gas (GHG) emission reductions using existing Clean Air Act authority, and ACC is working on several fronts to prevent the agency from extending GHG regulations to stationary sources. "We are developing a strategy that hopefully will result in EPA deferring action to give Congress more time to act," says ACC president and CEO Cal Dooley. The complexity of global warming regulations and the potential impact on the U.S. economy and manufacturing sector "really requires Congress to be involved," Dooley says. "Even our member firms that are part of the U.S. Climate Action Partnership have serious concerns about EPA promulgating GHG regulations under the Clean Air Act." The heightened concern about EPA’s progress on GHG rules is in part because the regulatory "clock is ticking," with EPA moving forward on rules and apparently on track to outpace efforts by Congress to pass climate legislation. EPA finalized its endangerment finding earlier this month and will finalize its rule requiring GHG reductions from mobile sources by March 31, 2010. The combination could trigger GHG permit requirements for new or modified facilities. There are several options available to industry in its bid to stop EPA from regulating GHG emissions using existing authority. Legal challenges to EPA's rule are likely to succeed in overturning it, Dooley says. However, due to the uncertainty that legal challenges would create for industry, ACC advocates an amendment to an upcoming bill that would delay EPA's ability to regulate GHG emissions from factories and other stationary sources. Legal challenges would focus on EPA's proposal to include only larger stationary sources. Industry groups say the agency cannot "pick and choose" the emission sources that would be controlled by the GHG reduction regulations. The Clean Air Act would cover sources that emit more than 250 tons/year, and EPA has proposed a "tailoring rule" that would raise the threshold to 25,000 tons/year. EPA would likely lose a lawsuit challenging the tailoring rule, but it is not clear whether a judge would institute a stay on the regulations while the legal finding is appealed, Dooley says. The uncertainty that would create for industry would stifle short- and long-term investment, Dooley says. Instead, it would be better for industry if Congress passed an amendment that prevents EPA from extending GHG rules to stationary sources, giving Congress more time to pass climate legislation. Senator Harry Reid (D-NV) "has made a commitment to act next year" on climate legislation, and it is in the interest of the U.S. economy and industry that EPA be prevented from implementing burdensome regulations that would be costly and inefficient, Dooley says. Chemical Week, 12/14/09, p. 10.

November 09, 2009

OSHA has slapped BP with an $87.4 million fine for failing to comply with a four-year-old agreement to fix process-safety problems at its Texas City, Texas, refinery, as well as for more recent violations of OSHA laws. It is the largest fine in OSHA history. OSHA says $56.7 million of the penalty is because of BP's failure to meet terms of an agreement to correct hazards that led to a March 2005 explosion that killed 15 and injured 170 workers. Within months of the accident, BP and OSHA entered into a settlement agreement, which expired in September. The remaining $30.7 million of the fine is because of a string of recent safety management violations identified by OSHA. "When BP signed the OSHA settlement, it agreed to take comprehensive action to protect employees," Secretary of Labor Hilda L. Solis said in a briefing. "Instead of living up to that commitment, BP has allowed hundreds of potential hazards to continue unabated." BP protests the citations and is seeking a review by the Occupational Health & Safety Review Commission, a body independent of OSHA. "We continue to believe we are in full compliance with the settlement agreement, and we look forward to demonstrating that before the review commission," Texas City Refinery Manager Keith Casey said in a statement. BP's process-safety performance, he added, has been among the "most strenuous and comprehensive that the refining industry has ever seen." However, OSHA says that since the 2005 accident, there have been several accidents and four fatalities at the BP plant. One of these accidents is under investigation by the Chemical Safety & Hazard Investigation Board (CSB). CSB Chairman John S. Bresland points to a "disturbing frequency" of U.S. refinery accidents. The board is currently investigating seven separate refinery accidents. Bresland urges BP to adopt recommendations springing from CSB's two-year investigation of the 2005 accident, including appointing a refinery process safety expert to BP's corporate board. Chemical & Engineering News, 09 November 2009, p. 12.

July 15, 2009

Concerns over BPA

CONCERNS OVER BISPHENOL A CONTINUE TO GROW: Women may want to reconsider that popular style accessory, certain hard plastic water bottles available in fashion-coordinating colors. New animal studies link the chemical bisphenol A, which leaches from such polycarbonate plastics and food can linings, with heart arrhythmias in females and permanent damage to a gene important for reproduction. Other recent research suggests that human exposure to BPA is much higher than previously thought.


Seeping through the cracks: Bisphenol A can leach into foods and drinks, especially when polycarbonate cracks, as shown in the cup above.

In animals, fetal exposures to BPA can be especially risky, sometimes fostering brain, behavioral or reproductive problems. Canada and some states are moving to ban polycarbonate plastic in baby bottles for that reason. But the new heart data suggest that even adult exposures to BPA might cause harm. In one new study, researchers treated mice with BPA during the middle of their pregnancies. All female offspring of the treated mice suffered an irreversible genetic change in one of the "master regulatory genes" of fertility, Hugh Taylor of the Yale School of Medicine reported in June in Washington, DC, at the annual meeting of the Endocrine Society. This gene, HOXA10, orchestrates the activity of "hundreds -- if not thousands -- of downstream genes," Taylor says. Through the genes it controls, HOXA10 helps synchronize the timing of uterine changes and ovulation. Without that synchrony, "you won't get pregnancies," he explains. The HOXA10 gene lost a methyl group (a carbon bound to three hydrogen atoms), permanently altering its activity and rendering uterine tissue hypersensitive to the effects of estrogen. That's probably not good, Taylor says, because "many diseases we see in adults owe their origins to fetal exposures" -- when genes become inappropriately modified. In another study presented at the endocrine meeting, Scott Belcher of the University of Cincinnati and his colleagues reported that BPA boosted "pro-arrhythmic activity" in isolated muscle cells from mice and rats. Arrhythmias, or heartbeat irregularities, are blamed for a higher mortality rate after heart attacks in premenopausal women compared with men, Belcher says. Science News, 18 July 2009, p. 5.

June 17, 2009

Those Plastic Bag Bans

COMPROMISES KEEP BANS AT BAY, FOR NOW: Plastic bag makers and their polyethylene suppliers can take a quick breath. With the exception of Washington, DC, and Edmonds, Washington, most of the U.S. communities that considered fees and bans this year have rejected them. That includes some major victories. As of this writing, the California Legislature appears to have tabled a proposal to put a 25¢ fee on single-use bags. New York Mayor Michael Bloomberg dropped his plan for a 6¢ fee -- his proposal was aimed more at generating revenue in a city hit hard by the collapse of the banking industry. And Philadelphia rejected a 25¢ fee, too. It's a good sign that communities desperate for tax revenue are turning away from bag taxes. This year, at least, bag makers have been able to fight the bans with a combination of responses: (1) a promise to recycle. Bag companies have been scurrying to set up and improve the scanty bag-recycling infrastructure; (2) a promise to use recycled content. The Progressive Bag Affiliates in April set a goal to use 40% recycled content in their bags by 2015. It was a major commitment, and no doubt it will have an impact, especially in the next few years -- assuming PBA's members can make rapid progress; (3) a reminder that bag fees are a tax on groceries -- a regressive tax that the growing ranks of unemployed Americans can ill afford; and (5) producer responsibility proposals that are more acceptable to bag producers. But remember, this is only a quick breath. Bag taxes and bans aren't going away. The industry still has to deal with a few this year. Sacramento County is considering a ban, and Seattle citizens will vote in August on a proposal to tax carryout bags. Don't be surprised if more taxes and bans pop up around the country. And even more likely will be additional proposals in Canada. Toronto implemented a 10¢-per-bag tax June 1st, and more communities are likely to follow suit. Bag taxes and bans have not been the top priority of the mainstream environmental movement, which is spending more energy on fighting global warming. But plastic bags will continue to be an easy target in coastal communities, especially in California. Legislators will be tempted again to levy taxes on bags once the economy improves. The bottom line is that bag companies will need to redouble their efforts to keep the promises they've made this year in order to hold back the tide against more taxes and bans next year. Plastics News, 06/08/09, p. 6.


April 28, 2009

Arctic Vulnerability

 ARCTIC MORE VULNERABLE THAN EVER: Arctic ice more vulnerable than ever. The ocean's ice cap is smaller than the long-term average and thinnest yet as melt season begins.


THINNING OUT: This spring, a larger fraction of sea ice in the Arctic is much thinner than average, a sign that the ice may be more likely to melt this summer. Light orange areas are covered by brand-new, first-year ice, which typically is less than two meters thick. Darker orange and red areas are covered by multiyear ice, which usually measures three meters or more thick.

The spring melting of the Arctic Ocean's ice cap has already begun, and data suggest that the ice is more vulnerable than ever: The ocean area covered by ice is one of the lowest ever measured by satellites, and a record high fraction of that area is capped by thin, first-year ice that's more prone to melt than older, thicker ice is. Recent satellite images reveal that for March 2009 an average of 15.16 million square kilometers of Arctic seas were covered by ice, says Walt Meier, a remote sensing analyst at the National Snow and Ice Data Center in Boulder, Colo. That's only 730,000 km2 more than the record low ice extent measured in the spring of 2006 but about 590,000 km2 -- an area slightly smaller than the state of Texas -- less than the long-term average, as tallied between 1979 and 2000, he announced during a press teleconference on April 6th.


  GOING DOWN: The proportion of Arctic sea ice that formed more than one year previously -- the so-called multiyear ice, which typically is thicker and more resistant to summer melting -- has been decreasing steadily in recent decades.

Thinner ice is more likely to melt over the course of a summer, says Ron Kwok, an analyst at NASA's Propulsion Laboratory in Pasadena, California. While multiyear ice is often three meters or more thick, first-year ice measures only two meters thick or less. In recent years, wind patterns have driven large amounts of multiyear ice from the Arctic Ocean into the North Atlantic, and winter refreezing hasn't caught up with that ice loss, he commented at the press conference. Although some small parts of the Arctic were cooler than normal this winter -- including the Bering Sea, where ice extent actually increased this year -- long-term trends for the entire region show an overall loss of ice, Meier notes. "We've lost about one-third of the ice cover that we had in the 1980s," he says. Science News, 09 May 2009, p. 14.

March 27, 2009

Opportunities during this economic downturn

SURVIVORS MAKING THE MOST OF THE RECESSION: The economic downturn, combined with interest on the part of hospitals and device makers to reduce liabilities, risks and costs, is creating opportunities for some materials companies that supply the medical industry. "The impact of downsizing is helping materials suppliers," said Larry Johnson, marketing director of health care for PolyOne Corp. The Avon Lake, Ohio-based company has grown its health-care materials business by 70% since the end of 2006 and expects to attain a 10%-plus growth rate in 2009 despite the rugged economic climate. Johnson said in an interview at Medical Design & Manufacturing West, held February 10-12, 2009, in Anaheim, that new opportunities are arising for materials suppliers that have weathered the economy so far, as some device makers need to replace companies that have gone out of business. Others are looking for marketing partnerships because they have reduced their own sales and marketing staffs.


The Breastlight in-home diagnostic device from PWB Health Ltd. allows women to perform breast exams at home. The portable device, made using Sabic compounds for the lens and housing, is one example of the rising demand for home health-care products.

PolyOne is in discussions with six or seven other companies on marketing partnerships, according to Johnson. "These companies still need to market even though they have downsized, so companies have asked us to form partnerships to market their products in health care," he said. Pressures to lower costs -- always present in the medical industry -- have accelerated because of the economy, providing materials suppliers with yet another boost. "Everyone is looking to take costs out, to make products lighter-weight and smaller, to use materials that reduce risks, and for products that increase the speed or throughput in providing hospital services," said Thomas O'Brien, industry manager for health care for Sabic Innovative Plastics US LLC in Pittsfield, Massachusetts. That creates the opportunity for material suppliers to provide resins for more in-home diagnostic devices, such as the Breastlight from Dumbarton, Scotland-based PWB Health Ltd., which uses Sabic compounds for the lens and housing and allows women to perform breast exams at home. The product is approved in Europe and Canada and is awaiting U.S. approval. "Home health care is really explosive," O'Brien said. "Things are becoming smaller and becoming more portable. It is all about throughput. Hospitals want to turn around patient care quicker and send people home with a portable testing or care device. The health-care trend is from in-patient to out-patient care and to devices that are portable, reliable, lightweight, durable and attractive.  " Plastics News, 03/02/09, p. 9 (PDF).

November 18, 2008

NANOTUBES DEEMED DIFFERENT FROM CARBON: Sensing confusion in the nanotech industry, the EPA has clarified its position on carbon nanotubes, saying they are chemically distinct from graphite and other forms of carbon. The move serves as a reminder that carbon nanotubes are considered new substances under the Toxic Substances Control Act (TSCA).

 Manufacturers of carbon nanotubes need to submit toxicity data on their products as part of premanufacture notice.


EPA first established its position on carbon nanotubes in 2007 but decided to issue a clarification now because "current pre-notice inquiries to the agency and questions in public forums still indicate a lack of clarity on this issue," the agency wrote in a Federal Register notice on October 31st. Under TSCA, manufacturers and importers of carbon nanotubes are required to notify EPA at least 90 days before they import or use carbon nanotubes for commercial purposes. That notification could trigger the agency to restrict the use of the product or ask for more toxicity data. EPA's notice is an indication that manufacturers are not complying with the law, says Richard A. Denison, a senior scientist with the nonprofit group Environmental Defense Fund. "I am dismayed by EPA's lax approach to enforcement," Denison says. Nonetheless, critics who would like more government oversight of the nanotech industry say EPA's latest move is a step in the right direction. But they add that several issues still need to be resolved. For example, EPA does not address nanoscale materials other than carbon nanotubes, says Andrew D. Maynard, chief science adviser of the Washington, DC-based nonprofit Project on Emerging Nanotechnologies. Numerous studies have suggested that the nanoscale forms of some materials, such as titanium dioxide or silver, are more toxic than their bulk counterparts. EPA's position on carbon nanotubes, however, is in line with that of the European Union. In June, EU representatives voted in favor of removing an exemption for carbon and graphite under REACH, the EU's chemicals management program, to close a loophole that allowed nanosized forms of carbon to be sold without testing. That exemption was officially removed on October 8th. Chemical & Engineering News, 10 November 2008, p. 10.

July 06, 2008

Where have all the flowers gone?

WHERE HAVE ALL THE FLOWERS GONE? These words from Walden hint at the careful plant and animal records Henry David Thoreau kept during his stay at Walden Pond in Concord, Massachusetts, in the mid-1800s. By retracing this young naturalist's footsteps, not once but twice in the past century, researchers have been able to chronicle the fate of hundreds of plant species as the New England climate has changed since Thoreau's time. Using that data, Harvard University graduate student Charles Willis and colleagues have detected a disturbing pattern, one that he described last week in Minneapolis, Minnesota, at the Evolution 2008 meeting.


Flower man: Thoreau closely tracked Walden Pond plants.

By building a flora family tree that incorporates the "Thoreau" species and mapping onto the tree each plant's response to the 2°C increase in the region's average temperature since the famed author was at Walden Pond, the researchers have discovered that climate change has placed whole groups of plants at risk and that the more charismatic wildflowers that prompt conservation efforts, such as orchids, are among the most vulnerable. The study is "an intriguing combination of historical data sets and modern molecular methods to address in a very novel way climate change effects," says Carol Horvitz, a plant evolutionary ecologist at the University of Miami, Florida. "I think it's brilliant." Science, Vol. 321, No. 5885, 4 July 2008, pp. 24-25.


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