More than 5,000 people die prematurely from conditions like lung cancer and heart disease because of emissions, according to the Massachusetts Institute of Technology.
Exhaust from aeroplanes cause a further 2,000 deaths annually while emissions from the energy and industrial sectors and pollution originating from Europe bring the overall total up to 19,000 deaths per year in Britain.
In contrast official figures state that 1,850 people were killed as a result of road accidents in 2010.
Prof Steven Barrett, who led the study, said: "It does appear to be the case that air pollution from road traffic causes more deaths per year than the number who die on the roads.
"But those who die from air pollution tend to die about 10 years earlier than they would otherwise, whereas people who die in road traffic accidents might be on average middle aged, so it is likely that road traffic accidents cause more loss of life years overall than air pollution."
The researchers made their estimates by comparing models of how gases circulate in the atmosphere against health statistics and the results of clinical studies.
The study, published in the Environmental Science and Technology journal, suggests that 40 per cent of the major pollutant – particles which measure up to 2.5 micrometers in size – come from abroad rather than from Britain.
Separate research by scientists from the Harvard School of Public Health claims that long-term exposure to air pollution raises the risk of various health problems in our later years.
Their study, published in the PLoS ONE journal, reported that every 10 microgram-per-square-metre increase in air pollution corresponds to a six per cent higher risk of hospital admission for diabetes, a four per cent higher risk for breathing conditions like pneumonia, and a three per cent higher risk of heart disease or stroke.
Prof Joel Schwartz, who led the study, said: "The difference between a rural area and a dense urban area is probably about five to ten micrograms, so those percentages might be telling of the difference between living in a clean, rural area and a heavily polluted urban one."