Underground air might cause DNA damage

"Luckily, most of them do not remain in the underground for any length of time," says scientist Hanna Karlsson. "However, particle levels are often very high. My results show that there is every reason to speed up the work being done to clean the air in the underground."

Every year, some 5,300 Swedes die premature deaths from inhaling the microscopic particles of coal, asphalt, iron and other materials that pollute the city’s air. These particles, which are the result of incomplete combustion, road surface attrition, etc. could be reduced if the right steps were taken; the problem is that it is not known which particle sources pose the greatest threat to human health.

To build up a picture of which particles are the most harmful, Dr Karlsson has compared how particles from a variety of sources affect cultured lung cells. The results, which are presented in her thesis Particularly harmful particles show that particles from the Stockholm underground are much more damaging to cellular DNA than the other sources tested (e.g. wood smoke and cars).

The airborne particles in the underground system largely comprise iron, and are formed by the abrasion of the train wheels against the rails. The damage is caused when these particles enter the body and form free radicals in the body’s cells. Free radicals are highly reactive molecules that can prove harmful to the cell’s DNA; although such damage can often be repaired by the cell, it can sometime remains untreated, and this increases the risk of cancer.

Another type of particle that stood out in the studies was that caused by the friction between car tyres and the road surface. The report shows that these particles trigger a powerful inflammatory response (i.e. a general defence reaction in the body). Levels of these particles are particularly high in the spring, when road surfaces dry out and cars are still fitted with studded winter tyres.

"It’s a serious problem, as these particles exist in large concentrations in environments that people remain in for long periods," says Dr Karlsson.

Apart from particles from the underground and the roads, the study also examined those released by the combustion of wood, pellets and diesel. None of the other types of particle tested were totally harmless. Modern wood- and pellet-burning boilers gave off much fewer emissions than old ones, but the particles produced were no less harmful.

Source: Karolinska Institutet

In nature, proteins sweep up nanoparticles
Here’s a pollution-control tip from nature: Deep inside a flooded mine in Wisconsin, scientists from several institutions including the U.S. Department of Energy’s Lawrence Berkeley National Laboratory have discovered a world in which bacteria emit proteins that sweep up metal nanoparticles into immobile clumps. Their finding may lead to innovative ways to remediate subsurface metal toxins.
Nature: economic growth impacts on China's air quality
China's spectacular economic growth during the last decade has brought many benefits – and some challenges. Global atmospheric mapping of nitrogen dioxide pollution performed by ERS-2's GOME and Envisat's SCIAMACHY reveals the world's largest amount of NO₂ hanging above Beijing and northeast China, as reported in Nature this week.
Method removes MTBE from water
A researcher has discovered an effective way to remove a troubling new pollutant from our nation's water sources.
Pratim Biswas, The Stifel and Quinette Jens Professor of Environmental Engineering Science and director of the Environmental Engineering Science Program at Washington University in St. Louis, has found a method for removing the toxin MTBE from water. MTBE (methyl tertiary butyl ether) has been detected at low levels in municipal water sources around the nation and in several cases has made its way into citizens' tap water.
Biswas discovered that a nanostructured form of a compound called titanium dioxide causes MTBE to react with dissolved oxygen so that it yields the harmless gas carbon dioxide.
Do laser printers emit harmful particles?
(PhysOrg.com) -- Researchers have investigated the possibility that laser printers emit pathogenic toner particles into the air, which has been a subject of public controversy. Some reports have suggested that laser printers release tiny particles that could have negative health effects.
Source of geysers on Saturn's moon may be underground water
Saturn's moon Enceladus may indeed hide an underground reservoir of water. Scientists at Jet Propulsion Lab in California, the University of Colorado and the University of Central Florida in Orlando teamed up to analyze the plumes of water vapor and ice particles spewing from the moon. They used data collected by the Cassini spacecraft's Ultraviolet Imaging Spectrograph (UVIS). Cassini was launched from the Kennedy Space Center in 1997 and has been orbiting Saturn since July 2004.
SRNL's microbes useful for for environmental cleanup and oil recovery
A unique, patent-pending collection of microbes that can be used both for cleaning up the environment and addressing our energy needs has earned the U.S. Department of Energy's Savannah River National Laboratory kudos from a newsletter covering the rapidly expanding field of nanotechnology.
Listening to dark matter
(PhysOrg.com) -- A team of researchers in Canada have made a bold stride in the struggle to detect dark matter. The PICASSO collaboration has documented the discovery of a significant difference between the acoustic signals induced by neutrons and alpha particles in a detector based on superheated liquids.
The Day the World Didn't End
Here's what didn't happen on Sept. 10th:
The world did not end. Switching on the world's largest and most powerful particle accelerator near Geneva, Switzerland, did not trigger the creation of a microscopic black hole. And that black hole did not start rapidly sucking in surrounding matter faster and faster until it devoured the Earth, as sensationalist news reports had suggested it might.

Underground air might cause DNA damage

Related stories:

News discussion: