Professor Edgar Morgenroth:

The Deputy is right. Particulate matter, PM, was known about. That is for sure. At the time the debate was very much about CO2. That is the point I am making. It is not that we did not know about it but it was not the No. 1 priority. In some ways it was almost allowed to happen because we knew that diesel vehicles were and have always been "dirtier". PM was known about decades ago. We had some evidence of the carcinogenic effects. We know a lot more now about how this happens exactly and we also know a lot more about the kinds of concentrations that one sees in heavily frequented routes. There has been a lot of research done in Europe.

On health damage, in the study we did not do a full cost benefit analysis. It would be a very interesting exercise because then we could use it to determine what the right level of excise might be. It might be equalisation; it might be more or less. This is the first step. That is what the report was aimed at. It was to raise awareness that fiscal measures can play a really important role and have played an important role in some areas. There are areas where fiscal measures are in place where we have not considered the environmental impacts at all and really have not thought about it. There are areas where we probably should where we know there might be an issue. The issue of company car taxation is an example. The UK made a change a number of years ago when it went from a similar system to our own, a mileage driven system, to one that was based on CO2, which has changed quite dramatically the composition of the company car stock. Fortunately in Ireland, we do not know much about company cars at all. One cannot find out the number, how far they travel or what engine size they have. That means one cannot do any research. It is something that ought to be addressed because there is scope to change the vehicle fleet much more quickly on the company car side than on the private car side. The typical privately-owned vehicle tends to be kept for a much longer period than a company car. When a company car is written off it tends to be passed on so there is a much quicker turnover.