High levels of air pollution are linked to an increased risk of mouth cancer, new research has revealed.

Scientists have previously linked high air pollution to a host of health problems, from an increased risk of dementia to asthma and even changes in the structure of the heart, with recent research suggesting there is no “safe level” of air pollution.

Writing in the Journal of Investigative Medicine, researchers in Taiwan describe how they discovered the association by looking at air pollution data from 66 air quality monitoring stations around the country collected in 2009, and combing this with data from the health records of more than 480,000 men aged 40 and over from 2012/13. In total, there were 1,1617 cases of mouth cancer among participants.