| 06 Oct 2025
Mitigating Mazuku Hazards: Implementation and Effectiveness of Local Dry‑Gas Degassing Measures in the Goma Area (Virunga Volcanic Province)
Abstract. Mitigation of carbon dioxide diffuse degassing hazards remains underexplored in comparison to other volcanic hazards such as eruptions, despite their persistent and deadly impacts on communities living in active volcanic regions. This study uses a mixed-methods approach – combining quantitative surveys and qualitative interviews –to assess household perceptions of the implementation and effectiveness of risk mitigation measures against mazuku, a locally known hazard caused by emissions of carbon dioxide in the western part of Goma, Virunga Volcanic Province. Data were collected across three sampling zones, capturing demographic characteristics, eruption risk experiences, and perceptions regarding the implementation of mazuku risk mitigation measures.
Findings reveal three locally recognised categories of mitigation measures: (1) emission-limiting measures, such as blocking gas with waste materials; (2) adaptive measures, such as house ventilation or living on upper floors; and (3) awareness measures based on orally transmitted local knowledge. Financial resources, gender and prior risk experience – often linked to length of residence – emerged as significant positive determinants of both motivation and perceived efficacy for the first two categories. Perceptions of awareness measures showed no significant variation across zones even between demographic profile groups. Spatial patterns in perceived implementation and perceived efficacy appear to reflect collective community mitigation approach rather than based on individual risk mitigation assessment, with some measures perceived as effective despite limited physical evidence of reduced gas concentration.
The study underscores the importance of co-creating mitigation strategies with local communities, adapting interventions to socio-economic realities and avoiding the importation of external mitigation measures that may lack contextual relevance. It also calls for complementary research measuring the actual effectiveness of these measures through physical monitoring of mazuku concentrations. These insights, grounded in a Global South context, offer a valuable perspective for the development of inclusive and effective volcanic gas risk management strategies.
This manuscript is well-documented and represents a significant contribution to the journal's scope. Understanding volcanic hazards, such as mazuku - 'evil winds' in native language, related to invisible, odourless carbon dioxide gas - and their impact on the daily lives of affected communities requires greater attention within disaster risk studies. This case study provides an opportunity to rethink the ways of assessing, understanding, and raising awareness about mazuku risk, particularly by integrating the lived experiences of individuals who encounter this hazard in contexts marked by territorial and socioeconomic inequality. Consequently, I recommend its publication with minor revisions. To enhance the quality of this work, I suggest considering minor changes (attached PDF). Below, I highlight some central topics:
1) Given that this hazard is known by the vernacular name mazuku or evil winds, I wonder whether awareness campaigns consider the perception of mazuku as a threat laden with beliefs. For instance, gas is perceived not only as harmful to health but also as associated with the 'evil' and the underground. Do the warning panels reference this notion of 'evil'? Additionally, it is noteworthy that, according to the interviews, people respect the danger but still approach it, mainly due to pressures from population growth and the need for livelihoods. This highlights a form of risk acceptability in contexts where the volcanic hazard is invisible, further explaining the complexities surrounding mazuku and its mitigation.
2) I suggest clarifying in the results whether people are aware of the volcanic origin of mazuku. This is important because mazuku is an invisible volcanic hazard that exists in people's daily lives, in their domestic and intimate spaces. This type of volcanic hazard differs significantly from others, such as tephra falls or lava fields that physically can destroy homes. Mazuku can be lethal and can infiltrate homes without causing physical destruction.
3) My previous point emerges from the tendency (within the data and results) to associate mazuku with atmospheric conditions (e.g., wind, rain, temperatures). I recommend looking for mentions of this in the interviews to better clarify the "risk acceptance". Is this acceptance of volcanic risk? Mazuku prevention and mitigation measures refer to volcanic risk, but do residents perceive it as such, or do they see it as a different type of risk?
4) I also suggest providing a better description of local knowledge (based on the case study), as the discussion and conclusion of the paper emphasize the importance of incorporating it into community-based mazuku mitigation measures.
5) Lastly, it would be valuable to raise critical questions: Is mazuku considered an area of interest for volcanology? Is it receiving little or much attention in research? Do existing studies on mazuku (regarding concentrations and locations) account for its presence in inhabited areas?
Incorporating these changes could enhance the mixed-methods nature of the article, providing greater emphasis on qualitative data, which appears to be less described and represented compared to quantitative data. Overall, this piece makes a valuable contribution to understanding mazuku, paving the way for informed decision-making in disaster risk reduction efforts in Goma, but also in other regions facing the hidden threats of volcanic gases in contexts marked by territorial inequalities.