Air pollution is a major contributor to ill health in the UK. Dirty air does not directly kill people; it cannot. However, it is estimated in the UK to contribute to the shortening of the lives of around 40,000 people a year, undermining the health of people with heart/lung problems.
In cities worldwide, pollution is increasing. Although, in the UK, air pollution levels have been generally decreasing. In many big UK cities safe limits on harmful particulates and oxides of nitrogen - NOx - are still regularly breached.
Experts in air pollution have argued that it has been under reported for decades and the issue has been thrust into the news because the UK government lost court cases over illegally dirty air and car makers were found to be cheating tests on car emissions. Scientists are also more confident now about the ways that air pollution harms people. It has recently been linked with dementia although that link remains debatable.
Diesel car manufacturers drew fire by cheating emissions tests. Diesel is much more polluting than petrol on a local scale, and the biggest proportion of pollution in the UK cities comes from road transport. However, in Greater London, private diesel cars contribute 11% of NOx - less than what people might have thought. Lorries - with far fewer on the roads produce the same amount. In Central London, just 5% of NOx comes from private diesel cars, compared to the 38% from gas for heating homes and offices.
Solving air pollution needs a many sided approach. The best value for money comes from targeting the really big individual polluters such as old buses and lorries. Insulating homes so they don’t burn as much gas would also save pollution. Furthermore, stopping the spread of wood burning stoves in cities might help and cutting pollution from ships would be a good port in cities. Reducing use of chemicals in the home would help a little bit. Ministers are also under pressure to offer a £3500 incentive for drivers to scrap old diesel cars, and politicians are nervous upsetting drivers.