A study led by the Spanish National Research Council (CSIC) has found that air pollution from traffic is linked to an increased risk of developing high blood pressure.
Published in the Journal of Hypertension, scientists analysed the daily concentration of ultrafine particles (UFPs), defined as particles with a diameter less than 100 nanometres found in the air across the city of Barcelona, and looked at their impact on people living in the city.
The primary cause of ‘ultrafine particles’ in urban areas is understood to be traffic pollution.
The hearts of over 2,000 people were assessed using ambulatory blood pressure (ABPM) monitoring, which is a portable device that is used to record heart rate, usually used for a period of 24 hours.
The analysis found that a rise in the daily concentration of air pollution from UFPs is associated with a "significant increase" in blood pressure.
Aurelio Tobias, a researcher at the Institute for Environmental Diagnosis and Water Studies (IDAEA-CSIC) and one of the research team said: "Ultrafine particles in the air is a cardiovascular risk factor and, as we have seen in the study, it also affects blood pressure. Specifically, an increase of 10,000 nanometres of ultrafine particles is associated with an increase of approximately 3 millimetres of mercury in diastolic blood pressure levels."
Data was extracted from the CARDIORISC registry, a database that collects daily blood pressure monitoring figures from patients selected by doctors from 223 primary care centres. In total, data from 2,115 patients were used spanning from 2009 to 2014.
A significant increase in blood pressure can lead to a higher risk of a stroke, heart attack, heart failure, kidney disease, respiratory problems or premature death, the research team warned.
"Other recent studies show the negative effects of pollution on both the reproductive and nervous system. It also affects brain development and increases the risk of cancer. Pollution, without a doubt is adding to the economic strain on the health system. It is vital to act now against the harmful effects of too much traffic," stresses Tobias.
Scientists believe that the measures currently in place to reduce traffic in large cities are not enough to stop the damaging impact of pollution. They explain that more needs to be done to protect citizens and reduce the risk of chronic and life-threatening diseases due to ultrafine air particles.
The researchers propose six measures that could lead to what they call “breathable cities” that could improve air quality and reduce the prevalence of UFPs:
- Giving the power of environmental quality control to individual metropolitan areas
- Improving public transport.
- Reducing cars by introducing a toll to enter the city.
- Setting up low-emission zones so that cars entering a city are ‘clean’.
- Rethinking the urban distribution of goods.
- Transforming and redesigning cities and their urban environment to promote healthy air quality, in areas that traffic volume has been reduced.
Núria Soldevila, Ernest Vinyoles, Aurelio Tobias, José R. Banegas, Alejandro De La Sierra, Manuel Gorostidi, Julián Segura, Juan J. De La Cruz, Miguel A. Muñoz-Pérez, Xavier Querol and Luís M. Ruilope. "How do ultrafine particles in urban air affect ambulatory blood pressure?" Journal of Hypertension. DOI: 10.1016/j.envres.2020.109237