Urban Air Pollution has been around for centuries. The London smog of 1873 is seen as the worst pollution event in history. The next big event as in 1952 when smog caused major disruption by reducing visibility and even penetrating indoor areas. This led to the Clean Air Act which gradually improved air quality.
However, the increased road traffic, especially diesel vehicles once again caused Pollution levels to rise. In February 2017 Britain has been sent a final warning to comply with EU air pollution limits for nitrogen dioxide (NO2) or face a case at the European court of justice. If the UK does not show Brussels how it intends to comply with EU law within two months, a court hearing with the power to impose heavy fines could begin later this year.