Strong impact on air quality by the Kagghamra fire revealed in new study
A recent study conducted by researchers from the Department of Environmental Science at Stockholm University has shed new light on the impact of the Kagghamra fire, which occurred south of Stockholm in December 2020, on the air quality of nearby residential areas.
The study, published in the open-access journal Atmospheric Environment, reveals a significant increase in concentrations of airborne particles, particulate heavy metals, and polycyclic aromatic hydrocarbons (PAHs) during the course of the fire, underscoring the importance of monitoring and addressing air quality during such events.
"Waste fires can have a strong impact on air quality. It is crucial to be ready to rapidly mobilize air quality monitoring equipment to get a good estimate of the actual risk to health and inform the population about appropriate measures, such as stay indoors," says Sarah Steimer, main author of the study and Assistant Professor at the Department of Environmental Science, Stockholm University.
The Kagghamra fire, which ignited in December 2020 and persisted until the end of February 2021, was a waste fire at a storage facility located in Kagghamra, Botkyrka municipality, south of Stockholm. The researchers conducted comprehensive measurements to assess the impact on local air quality in two residential areas situated near the fire.
Elevated concentrations of harmful chemicals and airborne particles
"Our study shows that on certain days during the fire, the concentrations of some harmful chemicals such as certain heavy metals (especially lead) and polyaromatic hydrocarbons (PAHs) found in the particles were strongly increased over the levels usually found in air in this type of environment. However, the concentrations were still below the limit values," Sarah Steimer emphasized.
In addition, the study shows that the Kagghamra fire had a profound influence on the air quality of nearby residential areas. Notably, a substantial increase in concentrations of airborne particles with diameters of 2.5 micrometers or less (PM2.5) and 10 micrometers or less (PM10) was observed when winds blew from the direction of the fire.
"During our measurement period, the Swedish environmental quality standards for PM10 were not exceeded, but our measurements cover only part of the long burning period. It is, therefore, possible the standard was exceeded, but we cannot say this for certain," says Sarah Steimer.
Wider impact of the fire
Regarding the potential reach of the fire's impact on air quality, Sarah Steimer pointed out that the data analysis is ongoing, but on certain days during the Kagghamra fire, pollution from the fire was observed as far as central Stockholm, over 35 kilometers away.
"If we assume that the emissions are similar to or likely more toxic than those from forest fires, then there were several days where air pollution reached unhealthy to even hazardous levels during several hours. During this time people should try to remain inside as much as possible and avoid vigorous activity. This highlights the importance of monitoring air quality during such fires to be able to give appropriate advice to the population," says Karine Elihn, co-author of the study and Associate Professor at the Department of Environmental Science, Stockholm University.
Despite the challenges posed by such waste fires, the study found that air quality quickly returned to normal once the Kagghamra fire was extinguished. However, the researchers are open to investigating future waste fires in the Stockholm area to understand potential variations in emissions.
The study was conducted in collaboration with SLB Analys at the Environmental Management Department of Stockholm City, the Department of Chemistry at the University of Oslo, and the Institute of Environmental Medicine at the Karolinska Institute.
About the Kagghamra fire
In December 2020, a significant fire erupted at a waste storage facility in Kagghamra, near Stockholm, within the Botkyrka municipality south of Stockholm. The facility, originally designated for storing up to 10,000 tons of demolition wood, wood, and metal construction waste, had faced prior complaints for exceeding storage limits in terms of duration and the types of waste stored.
The fire covered a vast area, resembling the size of a football field, with flames reaching 5 to 10 meters in height. Its proximity to a river, a bay, and a groundwater source presented a unique challenge, as traditional water-based firefighting risked environmental contamination. Consequently, the decision was made to extinguish the fire by covering it with sand.
The initial sand layer was in place by February 10th, 2021, markedly reducing smoke emissions and marking the conclusion of the open burning phase. By February 19th, 2021, the final sand cover was complete, officially signaling the end of the fire-fighting efforts.
To assess potential population exposure, two monitoring locations were established: Söderängstorp, positioned approximately 900 meters south-southwest of the fire, and Tegelvreten, located roughly 1,000 meters east-northeast of the fire. Monitoring included measurements of fine particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), nitrogen oxide (NO), and black carbon (BC). Data collection commenced in early 2021 and continued until May 3rd, 2021, providing essential insights into the aftermath of the Kagghamra fire.
These comprehensive measurements are vital for understanding the fire's environmental and public health implications.
Last updated: October 30, 2023
Source: Department of Environmental Science