Nine million Londoners under threat from particle pollution
Although transport is the main source, between a quarter and a third of London’s PM pollution comes from domestic wood burning.
Data from the London Atmospheric Emissions Inventory shows that all people living in Greater London are exposed to concentrations of fine particulate matter (PM2.5) higher than the World Health Organization’s guideline of 10 micrograms per cubic metre as an annual mean value. It also shows that 7.9 million Londoners – nearly 95 per cent of the capital’s population – live in areas that exceed the WHO limit by 50 per cent or more.
Both short and long-term exposure to PM2.5 increase the risk of mortality from respiratory and cardiovascular diseases, and the UK Committee on the Medical Effects of Air Pollutants (COMEAP) has estimated that exposure to PM2.5 causes some 29,000 premature deaths every year in the UK.
Approximately half of the PM2.5 annual mean levels in London originate from emission sources outside of the city, and even outside of the country, which means that London cannot resolve this problem on its own – national and international action is also required.
The main local source of PM2.5 emissions is road transport, mainly related to tyre and brake wear. Other big local sources are non-road mobile machinery (including construction machinery and inland shipping) and domestic wood burning.
In a letter sent to Environment Secretary Michael Gove in September, London’s Mayor Sadiq Khan called for more powers for London to clean up toxic air in the capital, including:
Tougher enforcement of emissions limits for bulldozers, diggers and other construction machinery.
Simplifying the policing of waterway emissions from the Thames, with a single regulator instead of the current five
Reforming the Clean Air Act to set tighter emission limits for wood-burning stoves and create zones where the burning of solid fuels is forbidden.
“Non-transport sources contribute half of the deadly emissions in London so we need a hard-hitting plan of action to combat them, similar to moves I am taking to reduce pollution from road vehicles,” the mayor said, referring to the new Toxicity Charge (T-Charge) that came into force in early October and targets London’s oldest, most polluting vehicles.
Wood-burning stoves are increasingly popular, and there is growing concern over their environmental impacts. Researchers at King’s College London have found that wood-burning in the capital accounts for up to one third of the city’s PM pollution, up from 10 per cent in the past.
The report “PM2.5 concentrations and exposure in London” (October 2017) by the Greater London Authority and Transport for London: https://data.london.gov.uk/dataset/pm2-5-map-and-exposure-data
The Guardian, 29 September 2017