Environmental Factor, September 2008, National Institute of Environmental Health Sciences
Extramural Papers of the Month
By Jerry Phelps
- Mercury Vapor Captured from Compact Fluorescent Bulbs
- Breathing Polluted Air Raises Blood Pressure
- Link Between Thunderstorms and Asthma Attacks in the Atlanta Metro Area
- Over-the-Counter Pain Medicines May Reduce Risk of Diabetes
Mercury Vapor Captured from Compact Fluorescent Bulbs
Brown University researchers supported by the NIEHS Superfund Basic Research Program have developed a nanomaterial that absorbs the toxic mercury vapor in compact fluorescent light bulbs. Compact fluorescent bulbs are the increasingly popular swirl-shaped bulbs that use 75 percent less energy than incandescent bulbs and have been touted as one method to save energy and fight climate change. However, there is a major environmental concern; they emit mercury vapor when broken or damaged.
The research team developed a nanomaterial that readily absorbs the gas. It can be used in packaging of new bulbs and disposal of burned-out or broken bulbs. The researchers have applied for patents and expect to enter into licensing negotiations with companies that could manufacture the packaging.
The material is a variant of nanoselenium and was developed by Robert Hurt and Brown engineering student Natalie Johnson. It absorbs virtually all the mercury vapor given off by broken bulbs. Hurt thinks the packaging can be developed at a low cost since only one to five milligrams of nanoselenium is needed to absorb the mercury from a single bulb. The team has also developed plastic bags that could be used to dispose of burned-out or broken bulbs.
Citation: Johnson NC, Manchester S, Sarin L, Gao U, Kulaots I, Hurt RH. (http://pubs.acs.org/cgi-bin/sample.cgi/esthag/2008/42/i15/html/es8004392.html) 2008. Mercury Vapor Release from Broken Compact Fluorescent Lamps and In Situ Capture by New Nanomaterial Sorbents. Env Sci, & Tech 42(15):5772-5778.
Breathing Polluted Air Raises Blood Pressure
A new study by cardiovascular researchers at the Ohio State University Medical Center is the first to report a direct link between air pollution and high blood pressure.
The research team exposed rats to levels of airborne pollutants that humans breathe on a regular basis. The levels were much lower than those seen in developing areas of China and India and some regions of the US. They found that short term exposure to these pollutants, over a 10-week period, elevated blood pressure in rats that were predisposed to the condition. These results are consistent with human observational studies that demonstrate similar blood pressure increases within hours to days following exposure.
Rats were exposed to concentrations of particulate matter air pollution comparable to levels seen in US cities with heavy commuter traffic. When rats were given angiotensin II, a naturally occurring hormone involved in blood pressure regulation, and exposed to particulate pollution, their blood pressure rose sharply as compared to rats that breathed filtered air.
A continuation of this work is being conducted in Beijing in association with the Summer Olympics. The researchers will measure vascular function in people before and after stringent air quality improvements are made for the games.
Citation: Sun Q, Yue P, Ying Z, Cardounel AJ, Brook RD, Devlin R, Hwang JS, Zweier JL, Chen LC, Rajagopalan S. (http://www.ncbi.nlm.nih.gov/pubmed/18599801?ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum) 2008. Air Pollution Exposure Potentiates Hypertension Through Reactive Oxygen Species-Mediated Activation of Rho/ROCK. Arterioscler Thromb Vasc Biol [Epub ahead of print].
Link Between Thunderstorms and Asthma Attacks in the Atlanta Metro Area
In a study co-funded by NIEHS and the EPA, researchers report discovering a link between asthma attacks and thunderstorm activity in the Atlanta metro area, home to more than five million people.
While a relationship between thunderstorms and increased hospital visits for asthma attacks has been known and studied worldwide, this study is the first to combine epidemiology and climatology in a research effort in the American South.
The research team used a database of more than 10 million emergency room visits over an 11-year period and found a 3 percent higher incidence of visits related to asthma on days following thunderstorms. A likely hypothesis offered by the research team for the increase in asthma is that pollen grains may rupture upon contact with rainwater, releasing respirable-sized allergens, and that gusty winds associated with the storm help to spread these particles. Exposure to certain pollen allergens is a known risk factor for asthma attacks.
The research team will continue its work to better understand the mechanistic basis of thunderstorm-induced asthma in an effort to improve intervention strategies and planning for emergency room services. They point out that this is particularly important considering that severe thunderstorms are estimated to double in the Atlanta area in this century.
Citation: Grundstein A, Sarnat SE, Klein M, Shepherd M, Naeher L, Mote T, Tolbert P. (http://www.ncbi.nlm.nih.gov/pubmed/18587040?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum) 2008. Thunderstorm associated asthma in Atlanta, Georgia. Thorax 63(7):659-660.
Over-the-Counter Pain Medicines May Reduce Risk of Diabetes
Researchers supported by NIEHS have added to a growing body of literature showing that standard dosages of several over-the-counter analgesics may prevent or delay the onset of Type 2 diabetes. The researchers used laboratory mice fed a high fat diet that triggered impaired glucose tolerance, a hallmark of Type 2 diabetes. They compared biologically relevant dosages of acetaminophen, naproxen, ibuprofen and aspirin for their respective effects on protecting against the development of a pre-diabetic condition in these mice.
Glucose tolerance was improved in the mice receiving acetaminophen and aspirin and to a lesser extent ibuprofen. Naproxen had no effect on glucose tolerance. The over-the-counter drugs partially prevented an increase in body fat, with acetaminophen and ibuprofen performing better than naproxen and aspirin. In liver mitochondria, the drugs inhibited succinate-dependent hydrogen peroxide production and lipid peroxidation. The researchers conclude from these findings that the over-the-counter analgesics diminished pro-oxidant processes that exacerbate inflammation and a pre-diabetic state.
With the rise in obesity in the US come increasing rates of Type 2 or noninsulin dependent diabetes. The common, readily available and relatively inexpensive drugs tested in this study may represent valuable therapies to delay or prevent the onset of Type 2 diabetes.
Citation: Kendig EL, Schneider SN, Clegg DJ, Genter MB, Shertzer HG. (http://www.ncbi.nlm.nih.gov/pubmed/18554574?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum) 2008. Over-the-counter analgesics normalize blood glucose and body composition in mice fed a high fat diet. Biochem Pharmacol 76(2):216-224.
(Jerry Phelps is a program analyst in the Program Analysis Branch of the NIEHS Division of Extramural Research and Training. Each month, he contributes summaries of extramural papers to the Environmental Factor.)