Nine out of ten people breathe polluted air - and worldwide it causes one in nine deaths, killing seven million people every year.
This week people across the globe will be marking World Environment Day and focusing on the problems of air pollution.
In low- and middle-income countries, 98 per cent of cities with more than 100,000 inhabitants fail to meet the World Health Organization’s air quality guidelines.
Ambient air pollution alone caused some 4.2 million deaths in 2016, while household air pollution from cooking with polluting fuels and technologies caused an estimated 3.8 million deaths in the same period.
In the UK there are around 20,711 deaths a year from air pollution with many of our cities' air quality being poorer than the WHO levels.
A new campaign has been launched by the World Health Organization, UN Environment and the Climate and Clean Air Coalition to dramatically reduce the number of deaths caused by air pollution by 2030 and to slow the pace of climate change.
The BreatheLife campaign is calling on communities to take action and pledge their support and is expanding through Asia, Africa and Europe, engaging with people in the health sector, schools and those working with young people.
Nearly 40 cities and regions, as well as some countries, have joined the campaign.
Statistics from the BreatheLife campaign
BreatheLife organisers say: "By acting now to reduce short-lived climate pollutants that are also air pollutants we will see substantial and immediate gains in public health, saving millions of lives, as well as slowing near-term climate change."
To find out how you can get involved, as well as seeing how your area compares to national and worldwide air pollution levels go to the BreatheLife website.