How football fans' barbecues choked Chilean capital

We are told we in England can now invite a limited number of guests for barbecues as lockdown restrictions are eased. There is little UK data on what this might mean for air pollution, but we do have evidence from Santiago, Chile.

Between 2014 and 2016 the Chilean capital experienced record-breaking pollution events. Emergency traffic restrictions were imposed but the particle pollution quickly disappeared on its own. There was no unusual weather and no smoke from distant wildfires. Analysis of pollution ratios ruled out traffic and industry. The cause was a mystery.

Then researchers checked sport schedules. The pollution peaked whenever the Chilean national football team played and people did not have work on the following day. The peaks could even be linked to the kick-off times. But they were not due to fans travelling to the stadium, they were caused by those who stayed at home. A survey before the final of the 2015 Copa América estimated that 29% of Santiago’s inhabitants planned a barbecue – around 100,000 fires lit at once.

Many English councils have already asked people to refrain from bonfires and barbecues to prevent smoke from entering the homes of vulnerable neighbours. We are all mindful of 2-metre physical distancing, but the smoke from your barbecue will travel a lot further.