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Last update: 04/29/2025 9:04

How is traffic affecting air quality levels?

A research led by the Instituto de Diagnóstico Ambiental y Estudios del Agua (IDAEA-CSIC) reveals how pollution levels vary in a city. The study, which has been carried out in Barcelona, analyses the quality of air, taking account of factors such as distances to the roads and building heights.

The scientists studied the air quality levels of BarcelonaThe scientists studied the air quality levels of BarcelonaRoad  traffic  is one of the biggest sources of pollution in cities. This research, published in the Science of the Total Environment journal, reveals that narrow roads surrounded by high buildings have worse air quality because the dispersion of  pollutants becomes harder. As a matter of fact, at some roads occurs a “canyon effect” that causes a bigger accumulation of pollutants in one side of the road.

The study puts into perspective the emissions of the city traffic, where contamination by nitrogen dioxide concentration (NO2) has not been reduced in the past few years. Moreover, 65% of the circulating vehicles in the Metropolitan area are still diesel engines.

“Governments  play an essential role in the reduction of emissions”, considers Fulvio Amato, one of the authors of the paper. “Citizens have the right to breathe air that does not harm their health and public administrations are legally obliged to respect and protect this right, even if citizens do not expressly request it”, he continues.

“It has been proven that the main pollution source is traffic , so it is necessary to act in this area, with measures that may seem unpopular at first, but would mean more  quality of life and health for citizens”, he says.

It is fundamental to offer a good alternative to the car to reduce emissions

As Amato explains, the necessary actions vary in every case, but on a general basis “improving public transport and  urban tolls” are the most effective measures when the problem is that NO2 emissions exceed the annual limit. He also points out that it is fundamental to offer a good alternative to the car, as well as “facilitating non-motorized trips”, either by bicycle or on foot.

Beyond the role of administrations, public awareness about the effects of pollution  on  health is essential to successfully carry out the necessary measures to reduce emissions.

Reference article: https://doi.org/10.1016/j.scitotenv.2019.05.434