“What is so special is that we were able to measure with completely new, live methods that enable us to understand how the smoke and various toxic substances develop over time, and how extinguishing affects these substances. No two fires are alike, and this also applies to the smoke they produce and what it contains. What’s unique here is that we took the measuring instruments out to an actual fire,” explains Vilhelm Malmborg, a researcher at Ergonomics and Aerosol Technology at LTH.
Over the past ten years, there have been positive developments in terms of better clothing and equipment to protect firefighters. But there still is little knowledge about how the emitted smoke particles vary over time for a given fire. In addition, there is often other, less protected personnel who work near a fire site in an emergency, and in the aftermath.
Measuring personal exposure
The Swedish National Forensic Centre (NFC) and MSB conduct forensics training every year by simulating fires in different environments. Real settings, such as housing, cafés, and offices, have been built in the training field. Each environment has a story behind it that simulates a realistic fire scenario. Rescue personnel then extinguish the fire as if it were a real incident. The LTH aerosol scientists in conjunction with Occupational and Environmental Medicine, Region Skåne took the opportunity to conduct air measurements during these exercises, and had with them a truck fully loaded with various aerosol instruments.
“The students, the MSB staff, and the forensic examiners wore sensors and other equipment so that we were able to measure the personal exposure to toxic substances and smoke particles. The unique feature of this experiment has been the time factor, where we could follow the change over the course of the fire and extinguishing events, and see how these events affected the composition of particles,” explains Joakim Pagels, a researcher at Ergonomics and Aerosol Technology and manager of the Exposure to Ultrafine Particles from Combustion Sources in the Work Environment project.
Time-resolved measurements have been used in other research areas, such as wood-burning, but are relatively new in fire research. By measuring gases and particles while fires are burning, the hope is to gain new knowledge about the best extinguishing techniques for diverse types of fires, and the best ways for rescue personnel to act in order to avoid the harmful particles during the course of the fire. For example, do oxygen-starved environments generate chemical reactions different from those generated in open-air combustion?
“It’s difficult to pit environmental risks against each other. But new knowledge about air emissions can offer rescue leaders the means by which to decide, for example, if and when to use special extinguishing methods to reduce the impact on air quality and to improve their work environment. In some cases perhaps, one should not extinguish a fire at all to keep the emissions from contaminating the soil and water, in other cases the reverse, to avoid emissions to the air. One hope is that we will be able to develop simplified measures of smoke exposure that can be used by rescue personnel for risk assessments in the future,” according to Vilhelm Malmborg.
New project investigates new material
The research group, in cooperation with researchers from the Division of Fire Safety Engineering at LTH and toxicologists at Karolinska Institutet, is also starting up a new project closely related to this research. The fire smoke studies conducted now deal with the current situation, while the new project will focus on emissions and risks in the event of fires that involve new materials. It is about identifying risks with new types of sustainable materials and structures, solar cells, and other energy sources. Lithium batteries are an example of such products that present new risks, which in turn can lead to the need for new extinguishing tactics. Another example is nanomaterials used in assorted products. What new risks do they pose in the event of a fire?
“The purpose of the research initiatives is to contribute to a safer working environment for the emergency services personnel in the transition to a more sustainable society. We have formed an interdisciplinary consortium that complements ongoing research programs nationally and internationally, reinforces national expertise in air pollution from fires, and increases the dissemination of knowledge to stakeholders,” says Joakim Pagels.