The Dieselgate scandal has highlighted the dangers of NOx emissions and the justified public backlash should be used as momentum to make sure public health is not put in further danger, write Jordi Sunyer and David Rojas-Rueda.
Jordi Sunyer is a deputy scientific director and researcher at the Centre for Research in Environmental Epidemiology (CREAL), in Barcelona. David Rojas-Rueda, a researcher also at CREAL, will be a speaker at the fourth International City Health Conference, to be held in Barcelona on 4 and 5 November.
This article was previously published by Planeta Futuro El País.
The main pollutants at the centre of the scandal are nitrogen oxides, which can be 400% higher in diesel cars than in petrol-fuelled cars, and particles, which can be 20 times higher in diesel-powered engine emissions. The “cheat device” installed on certain VW and Audi vehicles controls the way the NOx control system operates, resulting in an emissions increase of up to 4000%.
Nitric oxide and nitrogen dioxide are known collectively as nitrogen oxides or NOx. Nitrogen oxides are regulated because they have been scientifically linked to many serious health problems.
In the short term, exposure to them can lead to irritation of the airways, which can result in respiratory problems. In people with existing conditions, especially asthma, exposure can exacerbate their symptoms quite easily.
In the long term, NOx is also linked to cardiovascular and respiratory diseases. There is also significant scientific evidence that there is a link between NOx and increased mortality rate in the general population.
Nitrogen oxides can react with ammonia, moisture and other compounds to form small particles. These micro-particles can then penetrate the sensitive parts of the lungs, causing or worsening respiratory diseases such as emphysema and bronchitis, as well as aggravating heart conditions.
Furthermore, when NOx and volatile organic compounds (VOC) react in the presence of heat and sunlight, ozone is produced. Children, the elderly, people with respiratory diseases, and people who work or exercise outdoors, are at particular risk from the adverse effects of exposure.
Given the wide variety of effects on health, and its ability to react negatively with other contaminants, NOx is of particular concern.
By violating emission standards, VW and Audi have produced NOx emissions that could have been up to 40 times higher than were previously thought over a period of seven years. This could lead to an increase in the likelihood and prevalence of cardiovascular and respiratory diseases, as well as premature deaths. As a result, this should not just be treated as a breach of the clean air act, but also a breach of public health laws, something which is hardly reimbursable.
The problem of diesel cars, which many people consider to be the biggest threat to public health in the developed world, could have an even greater effect on the environment, particularly in the USA, where diesel cars are very prevalent.
What can be done? Firstly, we should ask ourselves whether we actually need more and more cars on the road. The second question, again to ourselves, should be why we buy vehicles from car manufacturers that do not care about public health.
For now, the production and sale of these cars that have been manipulated must be stopped immediately, and the cars that were sold during the period 2009-2015 should be repaired. Outside of the USA, emissions from the affected models, as well as from other models and other makers, should be verified.
At the Centre for Research in Environmental Epidemiology (CREAL), in conjunction with ISGlobal, we work on different projects that can provide sustainable modes of transportation. Of course, diesel-powered vehicles do not fall into this category. “Dieselgate” and the actions of VW-Audi should be the impetus for the removal of diesel cars from our roadways, as their effect on public health is too severe.
This scandal has shown us that self-regulation in the automobile industry does not work. Governmental controls, at least in the USA, do not either. Governments and lawmakers around the world must increase checks and controls on vehicle emissions.
Ultimately, it is a question of business ethics, as well as a need for greater accountability in terms of health and environmental factors.