Diesel exhaust causes lung cancer
The International Agency for Research on Cancer, a part of the World Health Organisation, has for the first time labelled diesel exhausts as a definite cause of cancer. The findings are based on research in high-risk workers such as miners, railway workers and truck drivers, but the advice to reduce exposure is extended to the general population.
This is big news, and has huge implications for air quality policy.
There has been an unhealthy trend towards diesel engines in recent years across Europe. In the UK, the percentage of diesel cars increased from 9% to 24% between 1995 and 2009,  and in July 2010, sales of new diesel vehicles outstripped petrol cars for the first time.  The current vehicle tax regime actively encourages the purchase of diesel models, being solely based on emissions of CO2, which are lower in diesel engines. However, diesel is no friend to the climate, once the black carbon content associated with diesel exhausts is taken into account.
Action needs to be taken to urgently reduce the use of diesel. We need to ban all diesel vehicles from our cities unless they are fitted with a filter to remove the microscopic particles, known as particulate matter, which are so harmful to our health. Germany has 58 such schemes, known as low emission zones, whereas London is the only major British city to have such a zone. Even the London low emission zone fails to regulate pollution from diesel cars.
The study’s focus on miners and railway workers points to the need to control emissions from diesel machinery and trains. This is a poorly regulated sector, so the EU needs to move urgently to introduce stringent emission standards.
Finally, we need to remove the financial incentives which are driving the move towards diesel.
While the point has been made that the overall number of lung cancers caused by diesel fumes is likely to be significantly less than those caused by smoking, this is a very different public health issue. Although socially complex, smoking is fundamentally the choice of an individual, whereas air pollution is not. In fact the health impacts of air pollution fall squarely and unfairly on lower socio-economic groups, who incidentally travel a fraction of the distance by car each year (the highest income quintile travel on average 8,000 miles by car each year compared with 3,000 miles for the lowest quintile).
Improving air quality is a matter of social justice because it will reduce the unequal health burdens on an already disadvantaged sector of society. Our work to raise awareness of air pollution in London will focus on key groups, including transport workers, to build a better understanding of the health impacts and how they can be reduced.
 Department for Transport (2009) National Travel Survey: 2008.