London Issues High Air Pollution Alert After a Week of Fog and Fireworks
Not a great week to breathe in London.
Mayor Sadiq Khan put out a high air pollution alert for Tuesday, November 10, after a weekend of thick fog and a lot of fireworks. Forecasters at Imperial College told him to do it. Their reasoning was simple. Dense fog plus very light winds let pollution pile up. His office says smoke from Bonfire Night and Diwali fireworks “is likely to have contributed.”
Hospitals and schools got a warning. Everyone else was told to look after themselves.
Sunday Was the Worst of It
On Sunday, November 8, London and the South East hit the top level on the government’s daily air quality index. Defra’s forecast that morning counted high and very high pollution in five regions. IQAir had London’s index above 170 around 6:30 a.m. One outlet reported that fine particles, the PM2.5 kind, went past World Health Organization limits.
Fireworks and bonfires on November 7 and 8 added smoke and tiny metal-bearing particles on top of everything else. Public displays ran all weekend too, including the big one at Battersea Park. How much came from fireworks and how much came from traffic and the usual sources? That detail isn't known.
Why Fog Makes It Worse
Normally wind clears the smoke. Not this time.
Jason Kelly, chief meteorologist at the Met Office, said steady high pressure brought light winds and clear skies. Clear skies mean fog. And November sun is weak, so the fog was slow to burn off. The smoke just sat there, low to the ground, right where people breathe.
Kelly said to expect one more night of dense fog, with a warning for some areas. After that, more cloud and wind should break things up. The Met Office also had a yellow fog warning out for parts of England and Wales earlier this week. It warned about delays and tricky travel through the end of the week.
What’s in the Smoke
Fireworks throw off very fine dust, and that dust carries toxic metals. Bonfires put out a lot of smoke and particles too. Both can irritate your lungs, and smoke from bonfires can make heart conditions worse.
Kids are more vulnerable to dirty air than adults. So are people with asthma.
How the Alert System Works
City Hall sends alerts to Londoners, schools, and boroughs when pollution is forecast to be moderate, high, or very high. High alerts also show up on bus stop signs and across the Underground. Imperial College makes the forecasts, and the levels follow Defra’s air quality index. The setup dates to 2016.
During past alerts, Khan has asked drivers to stop idling their engines. He’s also asked people not to burn wood or garden waste. Both make it worse.
Who Should Be Careful
The usual advice on high pollution days is simple. If you’ve got asthma, or a lung or heart condition, go easy outside. Same goes for older adults and small children. Skip the hard workouts outdoors. Keep your inhaler close.
This Happens Every Year
None of this is new. A 2019 study in Newcastle and Gateshead used thousands of sensors to track fine particles on Bonfire Night. Between 8 p.m. and midnight, readings tripled. Low cloud made it worse.
Phil James, a professor at Newcastle University, said you can smell the gunpowder and smoke in the air that night. He also said one spike probably won’t do long-term harm. The trouble would come if it happened every night.
This week was different. It wasn’t one night. It dragged on for days because the fog wouldn’t lift. That’s why the alert matters, especially if you’ve got a health condition.
A Few Easy Things
Check the air forecast before you head out. Don’t leave your engine running when you’re parked. Skip the garden bonfire. If you use an inhaler, carry it.
The wind should pick up soon, and the fog with it. Until then, London’s stuck breathing it in.
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