A piece of news
Some 430,000 people die each year in the European Union as a result of breathing polluted air. 50% of all pollution is caused by brakes and tires on vehicles and asphalt.
Particulates from brake, clutch and tire wear and dust from asphalt now make up 50% of all air pollution and this continues to increase. However, there is no legislation to regulate emissions from mechanical wear. Lack of knowledge as to the chemical nature of these particulates, their behavior in the atmosphere and impact on human health means that, right now, the only possible way to reduce this type of emissions is to decrease the volume of traffic.
The European experts that participated in the scientific debates Urban Air Quality: The Challenge of Non-Exhaust Road Transport Emissions, organized by B·Debate —an initiative of Biocat and the "la Caixa" Foundation— and the Institute of Environmental Sciences and Water Research (IDAEA-CSIC) on 11 and 12 July Barcelona, debated how to determine the composition and distribution of these particulates and how to reduce levels to protect human health.
Breathing polluted air is currently one of the top 10 causes of premature death in the world. According to the WHO, 430,000 people die each year for this reason in the EU alone.
During the scientific debates, experts from various countries explained measures being tested in Europe. One of these is the use of porous asphalt. Dr. Robert Gehrig, deputy director of the Laboratory for Air Pollutants/Environmental Technology at the EMPA (Switzerland), affirmed that roads asphalted with this compound show lower particulate re-suspension levels than those with cement asphalt.
Oslo, Helsinki and Stockholm, which have lower pollution levels than other European cities, are leading research into how to improve air quality because particulates from mechanical wear make up a larger part of air pollution there. As Dr. Mats Gustafsson, researcher at the Swedish National Road and Transport Research Institute (VTI), explained the reason is that "roads are covered in snow and ice most of the year and this forces us to use studded snow tires and salt and sand to melt the snow, which means that the dust level is much higher here than in other European countries."
Barcelona isn’t among the worst, but neither is it among the best. In Barcelona, air pollution is linked to unfavorable environmental conditions —many days of sun and little rain— and its high density. There are 16,000 inhabitants per square kilometer living in the city and more than one and a half million cars on its roads each day (data from 2008), half of which are from outside Barcelona. According to Dr. Xavier Querol, researcher at the IDAEA-CSIC, air quality has improved notably in the past decade because vehicles have evolved a lot to meet national and European directives, "but even so, PM10 levels in southern Europe are still above the average seen in central Europe.2
PM10, or particulates with a diameter of 10 micrometers or less, are those with the largest impact on human health as they can cross any barriers in the body and penetrate to the deepest parts of the lungs. The highest levels of this type of particulates are found in the historical centers of cities, where streets are narrower and have less airflow. This is also where we find the highest concentration of heavy metals from brake wear, as there are more traffic lights forcing drivers to brake continuously.
In Barcelona, in April and May, tests were done to add magnesium chloride or calcium magnesium acetate (CMA) to water used to clean urban streets. Both of these compounds help bond toxic particulates together, thus increasing their weight and allowing them to fall to the ground instead of being re-suspended in the air. The results of these tests will be known in the coming months. Results have already been seen in the city of Klagenfurt (Austria). Dr. Wolfang Hafner, head of the department of Environmental Protection in this city, explained in his presentation how CMA has improved air quality in the city. The tests have also allowed them to determine how, when and in which quantities this treatment should be used to maximize its effects.
"Air pollution is collateral damage of progress that must be minimized, as has been done in London and many German and Scandinavian cities, where the people have pushed politicians to prioritize air quality on their agendas. Here we have to do the same," said Querol.
In this line, Xavier Guinart, head of the Government of Catalonia Ministry of Town and Country Planning and Sustainability’s Air-Quality Monitoring and Control Unit, explained some of the measures included in the new Air-Quality Plan for the Barcelona Metropolitan Area, which aims to reach safer levels by 2015: discounts on tolls into the city for hybrid or less polluting vehicles, fostering the use of public transport and bicycles in the city, and reducing emissions generated by people and cargo traffic at the El Prat airport and the port of Barcelona.
The following reports include the most noteworthy declarations from the speakers:
You can also follow the debate on Twitter @BDebate with the tag #BDebate.