“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.
Katarina Sternudd | alfa
Satellites, airport visibility readings shed light on troops' exposure to air pollution
09.12.2016 | Veterans Affairs Research Communications
Oxygen can wake up dormant bacteria for antibiotic attacks
08.12.2016 | Penn State
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine