In September 2015, the German automaker Volkswagen was found to have illegally cheated federal emissions tests in the United States, by intentionally programming emissions control devices to turn on only during laboratory testing. The devices enabled more than 11 million passenger vehicles to meet U.S. emissions standards in the laboratory despite producing emissions up to 40 times higher than the legal limit in real-world driving conditions.

Now a new MIT study reports that Volkswagen is not the only auto manufacturer to make diesel cars that produce vastly more emissions on the road than in laboratory tests. The study, published this month in Atmospheric Environment, finds that in Europe, 10 major auto manufacturers produced diesel cars, sold between 2000 and 2015, that generate up to 16 times more emissions on the road than in regulatory tests — a level that exceeds European limits but does not violate any EU laws.

What’s more, the researchers predict these excess emissions will have a significant health impact, causing approximately 2,700 premature deaths per year across Europe. These health effects, they found, are “transboundary,” meaning that diesel emissions produced in one country can adversely affect populations in other countries, thousands of kilometers away.

“You might imagine that where the excess emissions occur is where people might die early,” says study author Steven Barrett, the Raymond L. Bisplinghoff Professor of Aeronautics and Astronautics at MIT. “But instead we find that 70 percent of the total [health] impacts are transboundary. It suggests coordination is needed not at the country, but at the continental scale, to try to solve this problem of excess emissions.”

The 10 manufacturers’ excess emissions may not be a result of unlawful violations, as was the case with Volkswagen. Instead, the team writes that “permissive testing procedures at the EU level and defective emissions control strategies” may be to blame.

The researchers report a silver lining: If all 10 auto manufacturers were to improve their emissions control technologies to perform at the same level as the best manufacturer in the group, this would prevent up to 1,900 premature deaths per year.

“That’s pretty significant in terms of the number of premature mortalities that would be avoided,” Barrett says.

Barrett’s co-authors at MIT are Guillaume Chossière, Robert Malina (now at Hasselt University), Florian Allroggen, Sebastian Eastham, and Raymond Speth.

Read more at Massachusetts Institute of Technology