Air pollution is a serious public health problem all over the world. But what is the source of so much pollution? How is it measured? How can it be combatted? Is it true that diesel is the most polluting fuel? What contribution can the electric car make towards improving the air?
What is the source of Barcelona’s pollution?
The origin of the excess of pollutants in the air comes mainly from car traffic, and to a lesser extent from construction work and the industrial sector. Every day more than a million vehicles move around Barcelona. In fact, it is the European city with the highest density of cars, with almost 6,000 per square kilometre, which is double that of Madrid and triple that of London.
Diesel vehicles, especially older ones, emit the most harmful pollutants. The vehicles on the road every day in the city generate 60% of the nitrogen dioxide present in Barcelona. Industrial activity also generates suspended particles, especially construction work and, to a lesser extent, air transport.
The environmental spokesperson and sustainability consultant, Josep Lluís Gallego, confirms that citizens are more concerned about traffic accidents than pollution, but that what really causes more deaths throughout Spain are the gaseous pollutants from the exhaust pipes of vehicles on city roads. Every year around 10,000 people die from exposure to this pollution.
How is pollution measured?
The main pollutants in Barcelona are suspended particles, nitrogen oxide, carbon monoxide, sulphur dioxide and ozone.
There are different types of suspended particles: the densest are those that our body is already accustomed to fighting, such as dust and pollen. The finer particles that penetrate to the air sacs of the lungs, and from there to the blood causing many respiratory and eye allergies, are generated by the combustion of hydrocarbons from diesel cars and the friction of wheels on concrete.
Nitrogen oxide is formed by gaseous chemical compounds that come from fuel burned either by cars, aircraft or industry. It is an irritant gas that has a pungent odour, is reddish brown and causes asthma and bronchitis, especially in children.
Carbon monoxide comes from vehicle exhaust pipes and, to a lesser extent, from heating. It is a colourless, odourless and tasteless gas that in high concentrations causes serious poisoning and can be fatal.
Sulphur dioxide is a colourless gas that irritates the skin and respiratory tract and can cause serious lung diseases. It comes from thermal power stations and industrial activity.
Ozone is a secondary pollutant, which means that it is not generated by human activity. It is formed by the action of sunlight coming into contact with nitrogen oxides and hydrocarbons.
In order to detect the presence of these pollutants in the air, the City Council of Barcelona has a series of environmental stations, spread throughout the city, which analyse and prepare reports on their evolution.
Even so, it would not be so alarming if the weather helped. With rain the concentration of all these pollutants falls to the ground and the atmosphere is cleaned. Therefore, when we have days without rain, or wind, the atmosphere becomes more charged and the air we breathe is more dangerous for our health.
How can we combat air pollution?
The main measure to reduce pollution is to limit the vehicles on the road in Barcelona and promote the use of cleaner vehicles, such as electric cars, and the use of public transport.
As of 1st January 2020 it will be prohibited to enter Barcelona with a polluting vehicle and the low-emission zones will be permanent, which will affect more than 125,000 cars. This is intended to reduce pollution by 15%.
How much does the electric car contribute to the reduction of pollution?
Josep Lluís Gallego is quite certain: if the vehicles on the road in our cities were electric, the urban pollution associated with traffic would be reduced by 90%. It would also reduce the consumption of oil. It would pacify traffic, which would be quieter, gentler and more efficient. In short, less aggressive for the environment and healthier for people.
The European Climate Foundation has published a study on the impact of the electric car on the continent and we can extract some very interesting data. If the current trend in the introduction of these vehicles in Europe continues, nitrogen oxide emissions will go from 1.3 million tonnes to 70,000 tonnes in just over a decade. 27% of all emissions causing climate change originate in Europe due to combustion cars and they are, therefore, the biggest emitter of greenhouse gases. In contrast, electric cars generate between two and three times less global warming over the course of their entire life cycle, from production to scrapping.
The European Climate Foundation estimates that by 2030, 25% of the vehicles on European roads will be fully electric and a further 50% will be hybrid.
Another study from the Massachusetts Institute of Technology concludes that the adoption of the electric vehicle will reduce oil consumption by 60% and therefore pollution. It adds that the reduction would be even greater if the electricity generated to charge electric vehicles came from renewable energies.