Traffic is the most important source of pollution for health in Barcelona city

• It’s the first study in Europe that analyzes mortality impact of 26 chemical substances of pollution.
• The CREAL and IDEA-CSIC study shows that traffic is the source of particles more harmful for health in the city of Barcelona, followed by construction dust, sulfates from shipping and industry, respectively

Researchers from Centre for Research in Environmental Epidemiology (CREAL) and IDAEA-CSIC from Barcelona report that the most important and toxic source of pollution in Barcelona city is traffic. Using data from 2003 to 2007, the results of the study indicate that a day with many traffic increase the number of daily deaths by 6% above the normal number of deaths. Subsequently, construction dust and sulfates from shipping and industry.

In this city, traffic produces more toxic pollution than industry. Pollution from traffic was the source most strongly associated with death from all causes as well as death specifically from heart disease.

This study shows that for first time in Europe "traffic particles are more toxic than those from another source because there are more ultrafine particles and chemicals in them” remarks Dr. Jordi Sunyer, CREAL co-director.

Other coordinator of the study and CREAL researcher, Dr. Bart Ostro, adds that “identification of the more toxic constituents of PM2.5, which is a mix of many different chemicals, can help target pollution abatement and improve the efficacy of the interventions” explains Dr. Ostro. He adds that also it can help people determine how best to reduce their exposures. For example, identification of traffic as an important source suggests that people should minimize exposures during rush hours by not exercising or biking near major roads when possible. A final advantage of identification of important sources is that it can help us understand the actual biological processes by which pollution causes health problems.

Drs. Xavier Querol and Aurelio Tobías, IDAEA-CSIC researchers, are co-coordinators of the study. PM2.5 sources identified in the study are traffic, sea salt, vehicle exhaust, nitrates, industry, fuel oil combustion, minerals, sulfates, road dust.

In fact, both the European Commission and the U.S. National Academy of Sciences have indicated that information on which specific sources of fine particles are most toxic should be a research priority.

FUTURE RESEARCH

The next step is the MedPARTICLES project funded by European Union which takes into account this study and further applies the method in Mediterranean countries like France, Italy, Greece and Spain (Barcelona, Madrid and Huelva).

Since the Barcelona study used a relatively small data set, it is important to replicate this analysis after more data (ie., more years) are available for Barcelona, conduct similar analysis for other cities in Spain as well as in other countries, determine the actual chemicals in the PM2.5 mix that are toxic and determine what part of the population are particularly susceptible to the sources that are toxic.

Reference article: The Effects of Particulate Matter Sources on Daily Mortality: A Case-Crossover Study of Barcelona, Spain. Environmental Health Perspectives. Doi: http://dx.doi.org/10.1289/ehp.1103618