Air pollution is monitored and regulated. Air quality targets for particulates, nitrogen dioxide and ozone,[3] set by the Department for Environment, Food and Rural Affairs (DEFRA), are mostly aimed at local government representatives responsible for the management of air quality in cities, where air quality management is the most urgent. In 2017, research by the Lancet Countdown on Health and Climate Change and the Royal College of Physicians revealed that air pollution levels in 44 cities in the UK are above the recommended World Health Organization guidelines.[4][5]