Early April’s mixture of air pollution and Saharan dust attracted considerable media attention but air pollution in mid-March was far worse. This prompted emergency measures in Paris and south Belgium including free public transport and car bans. No such actions were taken in the UK despite almost identical pollution concentrations.
Emergency measures were triggered by pollution accumulating in air that was slowly circulating over north-west Europe. Paris had air pollution above EU limits for over a week. Winds nudged the polluted air westwards to include most of England and south Wales around 9/10 March and then again between the 12th and 14th, when air pollution reached the top value of 10 in the UK’s air quality index.
Following the 1952 London smog we used to believe that the public health impacts from air pollution mainly occurred when pollution was very high. Today we know that the long-term exposure to the air pollution that we experience in our daily urban lives has a far greater effect on public health than short episodes. Reducing air pollution every day therefore would have a bigger health impact. For this reason over 40 German cities have abandoned emergency measures in favour of low emissions zones that ban the most polluting vehicles all the time – similar to the scheme introduced in London in 2008. The UK policies have also focused on reducing air pollution every day, but March’s pollution shows that these measures are insufficient to protect against episodes. Even with current policies, long-term air pollution exposure adds the equivalent of 29,000 deaths per year to the UK’s accumulating toll.