It's clear from this study that the pollution from wildfires can have a significant effect on public health.
Huge moor fires which burned above Greater Manchester in 2018 exposed five million people to dangerous levels of particulates, a new study has found.
The wildfires which engulfed Saddleworth Moor and Winter Hill, on the eastern slopes of The Pennines, were battled by more than 100 firefighters and soldiers, led to many homes being evacuated and caused a plume of smoke across a large swathe of north-west England.
A team of researchers, led by the University of Leeds, found that the blazes caused poor air quality over a large region - reaching as far as Bolton, Wigan and even Southport - almost 50 miles (80km) away.
They found that five million people were exposed to levels of dangerous particulates known as PM2.5 which were above World Health Organisation recommended levels on at least one day, between June 23 and 30 2018.
Using computer simulations to look at the economic and health impacts, the paper, published in Environmental Research Letters, also calculated that nine deaths were "brought forward" due to the fire.
This is a mathematical calculation of deaths which occurred earlier than they would have without the pollution from the fires.
The paper said that this can be calculated because exposure to particulate pollution is associated with increases in deaths from diseases such as heart disease and stroke.
The authors estimated the economic impact of the fires to be £21.1 million.
They said: "It's clear from this study that the pollution from wildfires can have a significant effect on public health.
"The smoke contains very high levels of toxic particulate matter aerosol, which can be transported long distances.
"When this smoke passes over urban areas, it adds to an already polluted environment and can cause very poor air quality.
"We should be aware that the smoke from wildfires can travel long distances, and can damage people's health, even far from the fires.
"Although people may not have been able to smell smoke, particulate matter was very high in areas far away from the fires, such as Southport and Wigan.
"Particulate pollution from the fires substantially degraded air quality over the north-west of England, leading the pollution levels much above the recommended levels."
The team said that large wildfires are relatively rare in the UK and there is little knowledge of the potential impacts of wildfires on public health.
But it warned that climate change scenarios predict that UK summers will become both hotter and dryer, which means wildfires are likely to become both more common with a consequent impact on health.
The Saddleworth Moor fire in June 2018 was the largest UK wildfire in recent decades, with more than double the burnt area of the most recent previous large wildfire in 2011, in Swinley, Berkshire.
The fires began on June 24 and burned for three weeks, covering 8km2 and with flames reaching 4m high.
The fires burned on moorland that was dominated by heather with an underlying layer of peat.
Dave Higgens is a reporter with PA.