Diesel cars contribute to about 10,000 deaths a year

They are the direct consequence of abuses in the environmental performance assessment for cars - that came to public attention with the Volkswagen (VW) case and the ensuing Dieselgate scandal in 2015.

The research - covering the 28 EU member states as well as Norway and Switzerland for the period of 2010 to 2017 - was conducted by the Norwegian Meteorological Institute (MetNorway), in cooperation with the International Institute for Applied Systems Analysis (IIASA) in Austria, and the Space, Earth & Environment Department at Chalmers University of Technology in Sweden.

This collaborative work is the first successful attempt to quantify premature deaths in each European nation, comparing the different levels of danger that threaten citizens.

The top four countries - Italy, Germany, France and UK - have the highest death toll (70 percent) due to the high number of diesel cars and their large populations, which equate to 50 percent of all Europeans.

The top ten list also includes the Netherlands, Poland, Spain, Belgium, Switzerland and Hungary.

The remaining 20 countries represent 23 percent of Europe's population, but only 10 percent of the premature deaths. Particularly, in Norway, Finland and Cyprus, the risks are at least 14 times lower than the European average.

"Had diesel cars met the EU emission limits, almost 5,000 premature deaths could have been avoided", says Jens Borken-Kleefeld, transportation expert at IIASA. "And even more lives, precisely 7,500 (80 percent of losses), could have been saved if diesel cars had emitted as little NOx as petrol cars."

This is because the EU had set much stricter limits for petrol cars that - consequently generating lower toxic emissions.

Excess diesel emissions are the result of loopholes in the EU environmental surveillance system. Automakers are required to prove to national control agencies that their vehicles meet binding limits - known as "Euro" standards.

Over the years, the EU has increasingly tightened these values (the lowest being the Euro 6), to make transportation progressively cleaner. However, this certification mechanism relied on outdated lab tests.

The Volkswagen case pushed both governments and the industry to admit the truth: Real on-road emissions were found to be much higher than lab values, peaking by up to 400 percent higher than the Euro limits.

In the wake of the public outrage, the EU sped up the introduction of real driving tests, designed to ensure a more accurate measurement of car emissions. This new procedure has just become mandatory for new car models - in September this year.

Nevertheless, it will only apply to all new cars in two years time.

Transportation is the largest source of air pollution, and is responsible for around 425,000 premature deaths in the EU, Norway and Switzerland, according to the European Environment Agency.

More than 90 percent of these deaths are caused by respiratory and cardiovascular diseases associated with exposure to fine particulate matter (PM). A key factor in the formation of this harmful pollutant is NOx gas.

"We managed to trace the population exposure to PM back to excess NOx emissions from diesel cars", said Jan Eiof Jonson from MetNorway.

The researchers used public data and a calculation methodology consisting of three main steps.

First, they quantified the exposure to extra PM generated from cars' NOx. Then, they estimated the risk of dying prematurely because of certain diseases related to PM. And, finally, they correlated this risk of premature death with the exposure to PM.

"We intentionally focused on deaths linked to PM originating from NOx. If we were to consider the direct effects of NOx and those of all pollutants, then we would have recorded much higher fatalities.", said Jens Borken-Kleefeld from IIASA.

A previous study, co-authored by the International Council on Clean Transportation and published in the scientific magazine Nature, calculated that 6,800 Europeans died prematurely in 2015 as a result of NOx emissions from diesel cars that exceed the EU limits.

"Our approach is independent but similar to the research reported on Nature", Borken-Kleefeld said.

"Our number of premature deaths is somewhat lower - as I said, 5,500. But it is absolutely in the range of acceptable uncertainty that, according to our calculations, it spans between 6,000 and 13,000," Borken-Kleefeld said, adding that their research "confirms the results of the Nature study".

He goes on to say that his research differs compared to the results of the Nature study because of "differences in the health impact assessment methodologies," and that his results "account for the variation between European countries much better".

"The Nature study, instead, came up with a total figure for all countries considered as a block, with no indication of their national breakdown," Borken-Kleefeld concluded.

This article is part of the International Investigation on Dieselgate conducted by MobileReporter.