This year, Guy Fawkes events caused five days of particle pollution problems. Fireworks caused increased air pollution on Friday and Saturday evening across the eastern half of England, including London, Southampton and Hull. On Sunday firework smoke was measured across northern England, Coventry and Chesterfield, and in Derry in Northern Ireland. On Bonfire Night itself particle pollution reached the maximum level of 10 on the UK air pollution scale in Chesterfield, Leeds, Sheffield, Stockton-on-Tees and York, and lingered overnight to cause further problems the next day.

In India, Diwali fireworks have been implicated in the severe smogs that affect the Delhi region each year. In 2016, the Indian capital was enveloped in a severe smog for more than a week after Diwali, leading to a ban on firework sales that has split public opinion. This year the courts have relaxed the rules to allow the sale of less polluting “green” fireworks that produce less smoke and do not contain metals such as lead and mercury. This may help, but it will not cure Delhi’s chronic post-monsoon smogs, which are mainly caused by burning of rice stubble in the surrounding region. So, in addition to firework restrictions, there is a clear need for alternative ways to clear crops to improve the air quality breathed by more than 63 million people in the area.