“Usually you can see the ‘super-polluters’ simply just by looking; particularly when they accelerate or climb a hill and a cloud of smoke comes out of the exhaust pipe”, comments the physicist Philip Siegmann, from the Department of Signal Theory and Communications at the University of Alcalá (UAH) and co-author of the study.
“People usually complain about the bad smell and the smoke, but the worst thing is that the nanoparticles that nobody can actually see or smell are always present in Madrid, for example, even when you think that you are breathing in clean air” the researcher points out to SINC.
The new study confirms that the “super-polluters” are, “by far”, the vehicles that emit the largest amount of nanoparticles. The report concludes that were these vehicles removed from the flow of traffic, the “total active surface” (TAS) concentration of the nanoparticles (the particle surface that interacts with the environment) could be reduced by up to 25%, and the concentration of particulate polycyclic aromatic hydrocarbons (PPAH) absorbed by the nanoparticles, which are known toxic substances, could be reduced by up to 48%.
The study, published recently in the review entitled Atmospheric Environment, has focused on distinguishing and quantifying which types of vehicles have a higher emission rate of nano- particles, namely the ultra-fine ones (less than 100 nm in size), that are implicated in the development of different diseases. Their reduced size enables them to be distributed within the body with hardly any detection by the defences of the organism, and can even cross the cell membranes. Some studies have already shown that these small particles stimulate allergic reactions, such as asthma, and the development of multiple sclerosis. Moreover, under continued and prolonged exposure, they can produce cancer, as is the case with tobacco.
The researchers have noted that one of the main emission sources of these ultra-fine particles comes from diesel powered vehicles, but this is less so for petrol powered vehicles. “In any case, it is the super-polluters that pollute the most, since these are usually the ones in poor working condition and with poor combustion” Siegmann points out. The expert considers that these vehicles need to be removed from the traffic flow.
In order to obtain measurements, the scientists had to follow moving vehicles and, through the window, record the data using two sensors located at the end of a tube. The recordings were taken every ten seconds and were made by sucking in the air so that the sensors could pick up the measurement peaks when they entered the trail of smoke emitted by a vehicle. In the case of the “super-polluters”, the PPAH measurement peaks ranged from 100 to 1,000 nm/m3, but in some cases this even exceeded this high quantity.
Less nanoparticle pollution in Madrid
The study data were taken in Madrid in 2001 and 2006 and in Mexico City in 2001, one of the most polluted cities in the world. Although they do not appear in the report, measurements were also taken in Boston (USA). The highest number of emissions of nanoparticles corresponded to Madrid, and the scientists relate the data to the fact that a high percentage of the cars in this city are diesel (nearly 30% in 1999-2001 and 50% in 2006), whereas in Boston there are fewer emissions of this type because nearly all the vehicles travelling on the roads are petrol driven. Mexico City finds itself in the middle, although there is a plethora of “super-polluters” in this city.
Nevertheless, in Madrid, the results confirm that over the last 6 years pollution from nanoparticles has reduced by nearly 65%. The researchers justify this because of the improvements that have been incorporated into new vehicles in order to comply with the European regulations regarding emissions, such as the ‘Euro 4’ level which will be replaced by the ‘Euro 5’ level in 2009.
Despite this, Siegmann recognises that ‘super-polluters’ are still on the roads in this city. “Anybody who is waiting at a bus-stop will have suffered from a cloud of smoke emitted by a bus as it accelerates”, he adds, “and in this cloud of smoke large quantities of all types of particles, including nanoparticles, are being emitted“.
Nanoparticles mainly come from human activities such as the combustion of coal, incinerators, vehicles, burning of rubbish, kitchens, barbecues and tobacco, but they can also be natural in origin, such as those emitted by volcanoes. In any event, the exposure of the human being to these substances has increased as a consequence of the industrial development throughout the 20th century, particularly with the advent of diesel driven cars, with the consequent health problems.
SINC Team | alfa
Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide
Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences