It had been thought that, at worse, air pollution was cutting life expectancy by two years or so, but researchers at Aarhus University in Denmark have discovered that this was based on false measurements.
They estimate that an increase in air pollution of 10 micrograms per cubic meter reduces life expectancy by between seven and 11 years. This is far higher than current figures suggest, but this is because the average victim of air pollution is 78.9 years old when they die, and so scientists have thought that pollution has reduced life expectancy by just two years.
But they're just seeing the end of a process, and the real impact of air pollution became apparent when the researchers used a 'lifetable' of 100,000 people with an age distribution that matches the general population.
Their findings have been echoed by researchers at the Harvard T.H. Chan School of Public Health who have also discovered that air pollution and ozone increases the risk of an early death.
Low-income families and those living in poorer areas were at higher risk, they found, and lowering pollution levels by just 1 microgram per cubic meter would save around 12,000 lives a year.
Lowering ozone levels would save an additional 1,900 lives every year.