In September 2015, the U.S. Environmental Protection Agency revealed Volkswagen's use of illegal "defeat device" software in its diesel cars.

The software routines allowed cars to pass emissions tests while still producing up to 35 times the legal limits of nitrogen oxides in real-world driving, setting off a scandal that is still being dealt with.

Volkswagen is proceeding with buybacks and modifications of affected cars, both in North America and Europe, but the excess pollution may have already had a significant public-health effect.

DON'T MISS: Volkswagen diesel buyback: some buyers still waiting

Excess emissions generated by Volkswagen diesel cars between 2008 and 2015 will cause 1,200 premature deaths in Europe, according to a new MIT study (via ScienceDaily).

Published in the journal Environmental Research Letters, the study looked only at the emissions from affected cars sold in VW's home market of Germany, which researchers pegged at 2.6 million.

That number includes cars sold under the main Volkswagen brand, as well as Audi, Seat, and Skoda.

2010 Volkswagen Golf TDI

2010 Volkswagen Golf TDI

It also dwarfs the roughly 560,000 cars in the U.S. confirmed to have illegal "defeat device" software, and that are subject to settlements mandating buybacks, modifications, and restitution for owners.

While the diesel vehicles studied were sold only in Germany, their emissions affected people in other European countries, according to the study.

Of the 1,200 premature deaths predicted by the study, 500 were in Germany, while the rest were in other countries.

ALSO SEE: Illegal VW Diesel Emissions: Tallying Public Health Damage (Feb 2016)

If VW modified all affected cars to meet emissions standards by the end of this year, generating no excess emissions starting in January 2018, it could prevent 2,600 premature deaths in Europe, the study said.

This study follows an MIT study published in October 2015 that looked at the health effect of excess Volkswagen diesel emissions in the U.S.

That study predicted 60 premature deaths in this country stemming from VW's diesel cheating.

2010 Volkswagen Golf TDI

2010 Volkswagen Golf TDI

The difference between U.S. and European figures is attributable not only to the larger number of cars in Europe presumed to be producing excess emissions, but also differences in population density, driving behavior, and atmospheric conditions, researchers said.

Volkswagen began modifying certain European-market vehicles to meet emissions standards last year.

CHECK OUT: VW exec pleads not guilty on diesel cheating charges

But modifications for U.S.-market vehicles have only recently been approved, and only for certain models that represent a relatively small fraction of the total number of affected vehicles.

That includes vehicles with the "EA288" 2.0-liter 4-cylinder diesel, sold only in the 2015 model year, plus about 65,000 of 85,000 affected 3.0-liter V-6 diesels, from model years 2013 to 2016.


Follow GreenCarReports on Facebook and Twitter