Air polution != "toxic gases from cars, taxis and motorbikes". That's only subset. Cities were dirty holes (including bad air) centuries before invention of cars.

Continuing, they didn't measure anything. They estimated.

Have a good reading :

In Paris, air pollution kills 5,400 people every year

https://www-francebleu-fr.translate.goog/infos/transports/a-...

https://www.francebleu.fr/infos/transports/a-paris-la-pollut...

Air pollution is responsible for more than 5,000 deaths each year in Paris according to a study published on Wednesday. Published in the Lancet Planetary Health journal, it calculated premature deaths linked to PM2.5 fine particle pollution and nitrogen dioxide (NO2) in 1,000 European cities. The French capital appears to be one of the cities where automobile pollution kills the most.

As to the sibling: air pollution != "toxic gases from cars, taxis and motorbikes". Your linked article says "road traffic, industry, airports, ports, but also wood and coal heating".

Furthermore, the lancet paper only estimates, they didn't measure anything. The linked article presents an hypothesis as if it was proved. It was not.