Researchers find evidence of large air pollution that comes with Bonfire Night celebrations, sending soot up into the night sky.
A study conducted by the University of Leeds monitored air quality, inquiring whether soot created from bonfires and firework displays - known as black carbon - can help in the formation of ice in clouds.
The team from Leeds then monitored the atmosphere during the Guy Fawkes Night events - known as the Bonfire Night or Fireworks Night, usually on November 5 in Britain - and found that soot were 100 times compared to normal levels.
Researchers published their report in the Journal of Geophysical Research: Atmospheres.
Particulates in Ice Formation
While ice forms naturally in clouds, tiny particles from desert and soil dust, as well as fungi and bacteria carried into the atmosphere can serve as "seeds." These can cause supercooled water droplets in the air to freeze around them. A significant increase in the concentration of these particles in the atmosphere could cause clouds to freeze, affecting the temperature around them and subsequently, the Earth's climate.
Researchers conducted experiments on Guy Fawkes Night in 2016, well into the early hours of November 6. The same monitoring was conducted in the following year, from November 4 to 5. Researchers used air filters to collect hourly samples used in the analysis. To capture their periodic samples, the team set up their equipment on the balcony of Leeds' School of Earth and Environment building - situated 15 meters above ground level and more than 500 meters from any bonfire or firework displays. According to the article from the University, their location offers a representative view of the air quality in the city.
The air filters were also washed, with the liquid being exposed to different temperatures in a simulation of varying atmospheric conditions. After exposure, researchers found that the soot produced on Bonfire Night did not serve as ice nucleating particles. However, the sheer volume of the pollutants surprised researchers, leading them to report on the incident.
Risks of Black Carbon
Environmental soot or black carbon has been shown to be harmful to health, with its exact mechanism being a subject of numerous studies over the years. One study shows that the trace amount of metal ions might be responsible for its toxic effects, finding a significant presence of metallic content (Silicon, Iron, Manganese, Titanium, and Cobalt) found in air samples.
Another significant health risk coming from black carbon is in the respiratory system. Among the first tissues affected from prolonged exposure is the respiratory epithelium, which serves as the linings in the lungs. Presence of soot in the airways interrupts the respiratory process, with the most common illnesses relating to this exposure being asthma and chronic obstructive pulmonary disease (COPD).
Michael Adams, lead author of the study and a research fellow in Atmospheric Ice Nucleation, explains that while their study demonstrated that black carbon does not have significant effects on the formation of ice on clouds, the levels of the pollutants "should be a warning to those with pre-existing health conditions," adding that the particles can enter the respiratory system.