An interactive map is providing real-time air pollution levels across London after a high alert this week, with data showing that some areas still pose moderate health concerns for people unusually sensitive to air pollution.
Dense fog combined with low wind allowed harmful particles to build up across the capital, prompting a high air pollution alert in London on Tuesday on advice from forecasters at Imperial College London. This was the fourth high alert issued by Mayor Sadiq Khan so far this year.
What caused the high pollution levels?
Forecasters say that smoke from Bonfire Night and Diwali fireworks, as well as wood burning, are likely to have contributed to the elevated levels. Vulnerable residents were urged to take particular care during the alert period.
Since Tuesday, levels have fallen across the capital, but some parts of London still have readings that could cause moderate health concerns for people who are unusually sensitive to air pollution.
Interactive map and borough ratings
The interactive map, created by the World Air Quality Index Project, collates data from more than half a million air quality monitoring stations worldwide. According to the site's data, between Sunday and Tuesday, much of the capital was in the "unhealthy" zone, meaning everyone could begin to experience health effects, and members of sensitive groups could experience more serious health effects.
The site suggests that active children and adults, and people with respiratory disease, should avoid prolonged outdoor exertion during such conditions.
Air pollution maps provided by the Apple Weather app showed some London boroughs covered by the highest pollution levels. The City of Westminster, Wandsworth, Lambeth, Merton, Ealing, Brent, Tower Hamlets, Greenwich and Bexley were all rated 10 earlier this week, with most other boroughs rated 8 or 6, including Croydon, Richmond upon Thames and Kensington and Chelsea. North London had somewhat clearer air, with boroughs including Haringey and Enfield mainly rated 2 or 4.
Impact and advice
Particularly foggy conditions caused disruptions at London's airports on Monday, with several flights from Heathrow and London City airports cancelled.
Lord Khan encouraged Londoners to help reduce pollution by walking, cycling or using public transport where possible, avoiding unnecessary car journeys and refraining from burning wood or garden waste. Information was also shared with GPs and emergency departments across the capital to help them support vulnerable patients.
Deputy Mayor for Environment and Energy Mete Coban said: "Toxic air is responsible for thousands of premature deaths in London each year, which is why the Mayor has done everything in his power to tackle it, which includes launching the world's largest clean air zone. It is really important we all do our bit to protect those who are most vulnerable as we continue working to build a safer and greener London for all."
