Wednesday 18 November 2020

 

Air pollution does not cause 40,000 deaths a year

Many thanks to LTT for summarising the Committee on the Medical Effects of Air Pollution’s latest position on air pollution and health (‘COMEAP sums up knowledge of air pollution and health links’ LTT 30 Oct). This can be distilled down to four words: “We really don’t know.”

I’m also grateful to LTT for being the only publication that I am aware of that reported COMEAP’s inability in 2018 to reach a unanimous agreement that there is any link between nitrogen dioxide (NO2) and mortality (‘Experts can’t agree on mortality risk of nitrogen dioxide’ LTT 28 Sep 18). 

It’s unfortunate that your correspondents Trevor Ellis and Alan Wenban-Smith seem more interested in attacking an organisation that they misname ‘Association’ (it’s the Alliance of British Drivers) than understanding the facts about air pollution epidemiology (Letters LTT 30 Oct). 

Once again we see the false ‘40,000 air pollution deaths’ claim used that the late respiratory physiologist Professor Tony Frew has explained publicly (https://tinyurl.com/y3y5eeul). Even the BBC understands it is a ‘statistical construct’ that doesn’t refer to real people or real deaths (https://tinyurl.com/y4us72nq). 

In 2016 the ‘guesstimate’ made by the Royal College of Physicians of an average three days of life lost per person in the UK due to air pollution didn’t sound scary enough, so they converted it into “340,000 life years lost” and then used a complex actuarial-type calculation to create 40,000 deaths. 

Of course, there are both negative and positive factors influencing average life expectancy, but the balance of all factors is strongly positive in favour of increased life expectancy – people are living years longer in the UK, not days or months shorter. 

The severe limitations of attempting to find statistical correlations using air pollution epidemiology, where there are always multiple risk factors in addition to air pollutants, are well understood – correlation is not proof of causation. 

I wrote a detailed letter to Dr Heather Walton of King’s College London almost exactly 12 months ago using peer-reviewed references to challenge claims in the Personalising the health effects of air pollution project but she never replied. 

It’s important to recognise the fact that air pollution studies using the likes of roadside monitoring stations do not measure actual individual exposure to outdoor air pollution (or indoors where we spend 90 per cent of our time). Sometimes they don’t even measure air pollution – ‘land regression models’ are used instead. 

Air pollution epidemiology on particulate matter (PM) is just embarrassing. In 1986 the US National Academy of Sciences (NAS) established that a smoker inhales 10,000 to 40,000 microgrammes of PM2.5 in a few minutes from smoking a single cigarette. As a life-long non-smoker I’m not here to promote smoking in any way or the hundreds of harmful chemicals in cigarette smoke, but smoking one cigarette is the equivalent of breathing in 50 to 200 days of PM from outdoor air. 

Smoking cessation studies (such as the 2018 American Heart Association Framingham study using 8,700 participants) demonstrate that there are no short-term deaths from particulate matter and quitting early enough results in smokers having the same cardiovascular risks as non-smokers at age 55 and the same life expectancy of 80 years. During an 80-year lifetime, the smoker who quit will have inhaled around 1.8kg of PM, compared to around 0.06kg for the non-smoker. 

There is a very clear correlation between life expectancy and wealth, where wealthy people living in areas with the highest air pollution levels also have the highest life expectancy, such as Kensington, Chelsea and Westminster. There is a clear north-south divide for life expectancy in the UK. 

Undemocratic low traffic neighbourhood (LTN) schemes are increasing air pollution. Even the mother of Ella Kissi-Debrah, the south London girl who died in 2013 after an asthma attack, which some claim was caused by traffic pollution, has described LTNs in the London Borough of Lewisham where she lives as “insane”. 

Air pollution alarmism in 21st century UK is aimed at regulating the economy and motorised transport out of existence and ignores other practical ways of reducing emissions such as fuel additives. 

Accepting ambitious targets for arbitrary air pollution legal limits, based on unreliable epidemiology without any viable cost-effective plan to meet them, results in regressive tax polices such as ultra-low emission zones and clean air zones. Such policies take at least an order of magnitude more money out of local economies than even the claimed benefits. This makes the poor poorer and the lawyers of ClientEarth richer, the exact opposite of what is required for longer, healthier lives. 

In the words of Professor Tony Frew, moving the goalposts to make something illegal, doesn’t make it dangerous.

 Paul Biggs Environment spokesman Alliance of British Drivers