Italy launches study into diesel filters after prosecutor's warning

From Reuters.com

Italy's health ministry said on Thursday it had ordered a study into possible health risks linked to diesel emission filters commonly used in vehicles throughout the European Union.
The concern over the filters, raised by an Italian prosecutor, pre-dates the Volkswagen emissions scandal and relates to devices which were installed by various car makers from 2008 onwards.
The health ministry decided to investigate the matter after Rome's chief prosecutor wrote to the government in July, referring to expert opinion alleging the filters increased the risks to health of diesel emissions rather than reducing them, and saying they posed an "extreme danger".
The letter, obtained by Reuters, was sent by Prosecutor Giuseppe Pignatone to Italy's ministers for health, transport and the environment. It said the filters reduced the size of pollutant particles, making them more easily absorbed by humans.

The letter is critical of all three ministries and says that the environment ministry has not conducted any studies into the impact of the filters on air quality or human health.

The scandal over VW cheating emissions tests has turned the spotlight on gathering concerns about air pollutants that diesel produces and its credibility as a cleaner alternative to gasoline.
An Italian health ministry spokesman told Reuters the ministry had asked the Superior Health Institute to conduct a study into the matter after receiving Pignatone's letter.