Green Party Manifesto: Air pollution

“Air pollution is a public health emergency. It is linked to the premature deaths of 40,000 people in this country.”

• A much-quoted report from the Royal College of Physicians and Royal College of Paediatrics and Child Health in February 2016 put the number of premature deaths in the UK linked to air pollution at 40,000.
• The science behind the report is complex, and the findings have been challenged. In particular, it doesn’t mean that air pollution literally causes 40,000 deaths a year.
• As the Committee on the Medical Effects of Air Pollutants has said previously: "it should not be interpreted as the number of individuals whose length of life has been shortened by air pollution, as this would only be true if air pollution were the sole cause of deaths. Rather, it is an estimate of the total mortality effect in the local population".
• What this means is that air pollution makes a small contribution to those deaths. It’s  linked to a number of health problems, including cancer, asthma, strokes and heart disease.
• Greenpeace quotes one expert as saying that the data going into the study has been “overinterpreted” and that “the basic data does not say that 40,000 people have died ... There is loss of life from air pollution but the discussion of deaths isn’t helpful”.  

We also checked the same claim in the Liberal Democrat manifesto.