Jul 22, 2020 06:29 PM
(This post was last modified: Jul 23, 2020 12:03 AM by C C.)
https://horizon-magazine.eu/article/four...-time.html
EXCERPTS: . . . Globally, wildfire smoke is estimated to cause over 339,000 premature deaths a year – far more than those who lose their lives directly in these blazes. The team is taking regular air samples at three locations in Greece – Crete, Athens and Patras. These are being combined with samples provided by collaborators around the world including in the US, the Arctic, India, Europe, Vietnam and in the air above the south Atlantic Ocean.
[...] ‘We are trying to understand the lifetime of smoke in the atmosphere and how it chemically evolves,’ said Prof. Nenes. ‘We want to characterise the impacts it will have on human health and the climate. Does it become more toxic (with age), or have a greater (warming) effect on the climate (than currently thought), or supply more nutrients to ecosystems when it falls back to the ground?’
One of the key findings the team has made since the five-year project began in 2017 is that particles released from burning vegetation in forest fires become more toxic over time. Smoke from forest fires can linger in the atmosphere for a couple of weeks as it spreads. While in the air the smoke particles chemically react with trace radicals – molecules with unpaired electrons – to undergo a process known as oxidation. This converts the compounds in the smoke particles into highly reactive compounds. When they are breathed in, these reactive compounds – known as free radicals – can damage cells and tissues in the body.
‘We know that breathing in smoke when you are close to a fire is not good, but we have seen that over time it gets worse – up to four times more toxic a day down the road,’ said Prof. Nenes, referring to some of their experiment results. These results showed smoke samples taken from the air more than five hours after they were released from a fire were twice as toxic than when they were first released and as they aged further in the laboratory the toxicity increased to four times the original levels.
‘This means that even if you are far away from a fire, if the smoke is being blown towards you, it can have a significant impact on health,’ he said. ‘People might not even be aware they are breathing in the fumes from a faraway forest fire, but it will be affecting their health.’
[...] This increase in toxicity is a particular concern as smoke from large wildfires is known to travel across whole continents and even oceans. ... ‘Wildfire smoke can circulate the globe,’ said Dr Mike Flannigan, director of the Canadian Partnership for Wildland Fire Science at the University of Alberta. ‘Smoke from intense fire can be injected into the upper atmosphere where strong winds – typically west winds – can carry it rapidly around the world.’
This means that large wildfires can have dramatic impacts on the air quality and visibility in cities far away from the source of the smoke, which can then make urban air pollution worse, increasing the risk of health problems and deaths among those living there. [...] More work is needed to understand the many sources of pollution in the air. Unravelling these sources is the goal of the Aeromet project. ... wildfires are likely to become more common and intense as global temperatures increase, and domestic wood burning on the rise, the smoke they produce could pose an even greater risk to human health and the environment... (MORE - details)
EXCERPTS: . . . Globally, wildfire smoke is estimated to cause over 339,000 premature deaths a year – far more than those who lose their lives directly in these blazes. The team is taking regular air samples at three locations in Greece – Crete, Athens and Patras. These are being combined with samples provided by collaborators around the world including in the US, the Arctic, India, Europe, Vietnam and in the air above the south Atlantic Ocean.
[...] ‘We are trying to understand the lifetime of smoke in the atmosphere and how it chemically evolves,’ said Prof. Nenes. ‘We want to characterise the impacts it will have on human health and the climate. Does it become more toxic (with age), or have a greater (warming) effect on the climate (than currently thought), or supply more nutrients to ecosystems when it falls back to the ground?’
One of the key findings the team has made since the five-year project began in 2017 is that particles released from burning vegetation in forest fires become more toxic over time. Smoke from forest fires can linger in the atmosphere for a couple of weeks as it spreads. While in the air the smoke particles chemically react with trace radicals – molecules with unpaired electrons – to undergo a process known as oxidation. This converts the compounds in the smoke particles into highly reactive compounds. When they are breathed in, these reactive compounds – known as free radicals – can damage cells and tissues in the body.
‘We know that breathing in smoke when you are close to a fire is not good, but we have seen that over time it gets worse – up to four times more toxic a day down the road,’ said Prof. Nenes, referring to some of their experiment results. These results showed smoke samples taken from the air more than five hours after they were released from a fire were twice as toxic than when they were first released and as they aged further in the laboratory the toxicity increased to four times the original levels.
‘This means that even if you are far away from a fire, if the smoke is being blown towards you, it can have a significant impact on health,’ he said. ‘People might not even be aware they are breathing in the fumes from a faraway forest fire, but it will be affecting their health.’
[...] This increase in toxicity is a particular concern as smoke from large wildfires is known to travel across whole continents and even oceans. ... ‘Wildfire smoke can circulate the globe,’ said Dr Mike Flannigan, director of the Canadian Partnership for Wildland Fire Science at the University of Alberta. ‘Smoke from intense fire can be injected into the upper atmosphere where strong winds – typically west winds – can carry it rapidly around the world.’
This means that large wildfires can have dramatic impacts on the air quality and visibility in cities far away from the source of the smoke, which can then make urban air pollution worse, increasing the risk of health problems and deaths among those living there. [...] More work is needed to understand the many sources of pollution in the air. Unravelling these sources is the goal of the Aeromet project. ... wildfires are likely to become more common and intense as global temperatures increase, and domestic wood burning on the rise, the smoke they produce could pose an even greater risk to human health and the environment... (MORE - details)