Yes, in the study I told you about that involved 500,000 Americans, we saw that life expectancy increased in all the cities where pollutant rates had been reduced. Life expectancy even increased by four to five years in entire neighbourhoods.
We can draw a parallel with tobacco. In the end, knowledge on this topic included knowledge on the environment. However, it was easy with tobacco. It was the first factor in Framingham. First, people either smoked or didn't. There was a clear line. Next, we could see how much they smoked: 5, 10, 25 cigarettes or three packs per day.
Measuring how many pollutants we are exposed to is a lot of work. It was a very complex undertaking. As soon as everyone started measuring, we got all of this new data. And it is very clear: what comes out of something that uses diesel is much more toxic than what comes out of a cigarette.