A new study suggests 8.8 million deaths a year around the world can be attributed to dirty air, chiefly fine sooty particles pouring out of vehicle exhausts, factories and power plants.
Co-author Professor Thomas Munzel, from the University Medical Centre Mainz in Germany, said: “To put this into perspective, this means that air pollution causes more extra deaths a year than tobacco smoking, which the World Health Organisation (WHO) estimates was responsible for an extra 7.2 million deaths in 2015.
“Smoking is avoidable, but air pollution is not.”
In Europe alone the researchers put the excess death toll figure at 790,000 – twice the previous estimate.
Air pollution was thought to have caused 64,000 deaths in the UK in 2015, including 17,000 fatal cases of heart and artery disease.
More than 29,000 other British deaths linked to air pollution were due to a range of conditions such as cancer, diabetes and chronic lung disease.
Average life expectancy was reduced by 1.5 years among people in the UK dying as a result of air pollution, according to the study.
Smoking has meanwhile resulted in more than 100,000 hospital admissions in Scotland during 2017 – down 11 per cent over the past decade.
Smoking was the primary reason for about 51,400 patients over 35 being admitted to hospital in 2017 – a 21 per cent reduction since 2008 – and contributed to a further 49,100 admissions.
Tobacco use was the primary cause of 50 per cent of cancer admissions linked to smoking, according to the official figures.
A Scottish Government spokeswoman described the figures as “encouraging” and said: “People are living longer, healthier lives, but, despite our best efforts, we know deeply ingrained social inequalities persist.
“Significantly reducing smoking rates remains a priority and our tobacco action plan published in June 2018, focuses on addressing health inequalities and targeting smoking rates in the communities where people find it most difficult to quit.
“The number of smokers in Scotland has fallen in recent years and we are committed to reducing this further, particularly in the most deprived areas, where there are the highest smoking rates.”
Deaths and hospital admissions caused by diabetes have meanwhile risen in Scotland in the past decade.
Last year saw fewer people admitted to hospital for diabetes-related conditions, but the number of people whose death was linked to the condition rose to 6,480 in 2017.
The prevalence of diabetes, particularly type 2 which is linked to diet and obesity, is also increasing rapidly, according to the Scottish Diabetes Survey.
The survey estimates almost 300,000 Scots had diabetes in 2017, with 17,000 new cases diagnosed.
Commenting on the increase of people in Scotland with diabetes, the government spokeswoman added: “This is due to better care and people living longer with the condition. However, this increase parallels the risk of admissions.
“Since 2010, the Scottish Government has implemented a number of initiatives to improve diabetes care which will help to reduce unplanned hospital admissions.
“Action includes improving blood glucose control by providing £10 million additional funding during the course of this Parliament to support an increase in the provision of insulin pumps for adults and for Continuous Glucose Monitors.
“In addition, our Diet and Healthy Weight Delivery Plan strives to make a significant impact on the prevention and remission of type 2 diabetes.
“This includes our commitment to invest £42 million over five years for the development of weight management for people with, or at risk of, type 2 diabetes as part of implementing our Type 2 Diabetes Prevention Framework.”