May we have fresh air to breathe – please

The 1952 London smog taught us that air pollution caused people to die in the days and weeks that followed a short period of very high pollution. If we could only prevent smog episodes then it was thought that the air would be safe. A study in the 1990s changed this view. Thousands of people living in six US cities were tracked over 14 years. Having allowed for smoking and other factors, people lived shorter lives in the most polluted cities, showing, for the first time, that the particle pollution that we experience every day affects our health.

In a new study scientists at Imperial College London have now looked at people over four decades. 368,000 people (1% of English population) were selected from the 1971 census. The researchers then looked at the next three censuses to check if the 1971 people were still alive. Survival was associated with their local pollution in the decade that they died, but it was also linked to the air pollution that they breathed up to three decades earlier. The effects of air pollution in 1971, 1981 and 1991 could still be detected in the death rates of people in 2001.