Air quality in London is a multi-pollutant problem. Numerous pollutants from numerous activities create a toxic soup, which is made worse by different weather conditions. And a few sources of emissions are difficult or impossible to control or reduce. For example, PM comes from many natural sources, such as sea salt, forest fires and Saharan dust.
The good news is, many pollution sources – like road transport and most industrial processes – are both manmade and controllable. Switching to electric vehicles, for example, virtually eliminates direct fossil-fuel combustion emissions from cars.
Focusing on the sources that we can control provides a huge opportunity to reduce pollution, especially since acting on a single source can address multiple pollutants. For example, lowering emissions from road transport lowers NOX and PM as well as secondary pollutants like ozone.
Largely a manmade problem, ozone is formed predominantly from the interaction of other pollutants like NOx, volatile organic compounds (VOCs) and methane. VOCs are released from burning fuel such as gasoline, wood, coal or natural gas. Methane is emitted through a range of manmade activities including oil and gas and agriculture.
Through the stationary and mobile monitoring network, Breathe London aims to determine the sources of pollutants on a granular level. We’ll do this by measuring carbon dioxide (CO2), an important marker, alongside the other air pollutants. By studying the ratios of pollutants to CO2, we can gain insights into what is causing the pollution. This data can then inform smarter policies and approaches to building healthier communities.
The information on this page comes from the 2016 London Atmospheric Emissions Inventory (LAEI), which catalogues London’s emissions by source and location. The LAEI covers the 33 London Boroughs, the City of London, and the geographic area of Greater London.