Comprehensive laboratory study on the toxicity of smoke gases during vegetation fires

This study by Kira Piechnik, Lukas Heydick, Anja Hofmann, and Andrea Klippel investigates the composition of smoke gases in forest and vegetation samples to draw conclusions about the actual smoke gas composition during wildfires. 

The focus is particularly on regions with extensive pine forests, like in Eastern Germany. The relevance of smoke gases is well illustrated by the example of wildfires in Québec, influencing air quality in New York, in 2023.

Read the full study on the Wiley Online Library

The FTIR measurement results revealed that the smoke consisted of various gases, including acetaldehyde, acetone, acetylene, acrolein, ammonia, benzene, hydrogen cyanide, ethane, ethanol, ethene, formaldehyde, carbon monoxide, carbon dioxide, methane, methanol, sulphur dioxide, nitrogen oxides and toluene. 

Traces of hydrogen chloride (HCl) were occasionally detected in very low concentrations (< 0.1 ppm). Due to the predominant zero concentrations, this gas was not further considered in the analysis. 

Upon comparison with AEGL values, five gases were identified as the primary smoke gases based on their toxicological relevant concentration: acrolein, hydrogen cyanide, formaldehyde, carbon monoxide and sulphur dioxide. 

The significance of the topic of wildfires is apparent due to the prevalence of fires not only in Germany but also worldwide. Numerous research projects are already addressing the development and optimization of operational tactics and the use of satellites for wildfires detection. 

To implement these efforts, knowledge of the toxicity of wildfires smoke is essential, requiring appropriate reference values. The application of AEGLs or IDLH is critically examined, weighing the pros and cons. In this context, it has been decided that they are not unsuitable for a preliminary assessment of acute toxicity. This decision is based on the understanding that these values are used in chemical industry accidents and serve as limits for airborne pollutants.

Meteorologically speaking, the onset of spring marks the commencement of the annual wildfires season, during which reports of wildfires in Germany, Europe and worldwide surge in frequency.

Wildfires refer to fires outside urban areas. There are different terms used for this phenomenon, in Australia, bushfire predominates, while in Europe, forest fire is more commonly used for wildfires and bushfires. 

In this paper, the term wildfire is used to describe fires affecting forests and vegetation outside urban areas, as is common in US usage. 

As is well-known, national borders play no role in the spread of fires and smoke, as illustrated by the last year's example of the wildfires in Québec, Canada. Due to wind direction and strength, the smoke affected the air quality in New York, which is located more than 700 kilometres away. 

Despite being a small fire (3 ha) in Saxony, Germany, compared to Canada (burnt area was less than 375.000 ha), the large smoke plume shows that even in relatively small fires, a significant amount of smoke gases is produced.

Photo Credit: Wikipedia Commons License

Smoke from wildfires in Quebec, Canada shrouds New York City on Wednesday, Jun 7, 2023.

(Marc A. Hermann / MTA)

Date: 7 June 2023, 13:44:24

Source: https://www.flickr.com/photos/mtaphotos/52959202838/

Author: Metropolitan Transportation Authority