Table 3.

Top five ranked research topics and areas of focus identified by interview participants through deductive analysis

Research topic (category)	Areas of focus (subcategory)	Examples of meaning unit (quotes)
Understanding and mitigating effects of smoke inhalation on respiratory health	Development of appropriate mitigation strategies	“it’s demoralizing sometimes being out there and not having a mask when you see, [like] … Police officers, or other agencies that are assisting us with different things, like not even really in the smoke, and wearing like large masks to protect their health, so. Um, I think it’s definitely valuable to continue looking into that and to continue pushing to get us some, um, sort of lung protection. Cause, you, you [sic] definitely feel it., Like after fire season your lung capacity is, um, it’s, it’s [sic] not what it was at the beginning of the season” (P1, wildland firefighter) “I think most firefighters are pretty aware that it’s not good to be breathing in what we’re breathing in, but we’re just at this standstill of what it seems like finding the right PPE that’s appropriate for the job. So, I think research sort of on that more practical side on what, like what apparatus is going to work for us would be really important at this stage” (P4, wildland firefighter) “You know, actual things other than like bring a mask, like if wearing mask is the only way, great. But also, beyond wearing a mask, which I think would take a while to find the right mask and the right buy in, what are the real facts, don’t do it? It’s like if you’re doing it, what’s the distances, like a lot of information about, people will be around smoke[sic], probably not wearing masks at some point. What are ways to mitigate, or like mitigate some of those things in alternate ways?” (P5, wildland firefighter)
	Understand exposure	“like the smoke inhalation, like what does that look like? Like what particulates, how much, like exposure, which kind of smoke you’re putting in, like how, what factors influence that, like what you’re actually doing and how can you like minimize that” (P5, wildland firefighter) “the obvious one that stands out to me, that like, you know, I notice a lot more on the line, is that sort of long-term exposure piece to smoke. Um, it would probably be like fine particulate matter. Cause, there’s a lot of times where, you know, in the later stages of a fire we are looking for smoke and looking for heat, and on our hand and knees in very, very [sic] fine ash with no PPE and um, and I think that probably proposes like a significant health risk. Um, I know it’s been documented in other fields that kind of any really fine particulate matter like that is detrimental to your lungs, and we just go in with zero PPE and zero information about it” (P14, wildland firefighter)
Fatigue and sleep	Determine optimal amounts of sleep	“what is the optimal amount, amount of sleep that like a firefighter should be getting? Or what is the optimal amount of rest in order to fully, like, kind of reset our minds and reset our bodies, uh to get ready for that next fourteen-day deployment. I don’t know, like fourteen to three just seems like it was pulled out of the air, so, um, I’d be curious to know like what, what is the proper amount of rest that we should be getting” (P1, wildland firefighter) “the quality of sleep, the length of shifts and whether or not they’re able to achieve—or obtain—quality sleep while they’re in the field, and whether or not that is, um, impacting on their safety while working” (P6, researcher)
	Understand impacts of long-term fatigue	“the short-term fatigue of like day-to-day, as opposed to the long-term fatigue of a season and how that affects you season to season kind of thing” (P3, wildland firefighter) “when you have, have 8 hours off between shifts, including you know going home, cooking a meal, taking a shower, all things that you do at home, so that adds up over time. So yeah, I think it’d be interesting to see how that would affect um kind of like overall fatigue, long term fatigue” (P2, wildland firefighter)
Mental health	Understand mental health impacts during and after fire season	“people kind of just starting out, that you know, everything seems like super, super fun and exciting to start, and then you know, the season ends and the reality of what you went through kind of sinks in” (P1, wildland firefighter) “but you know, the day-to-day and how that effects morale at your base, or how that might affect behaviour dynamics between groups of people when you’re stuck out there at a miserable fire for weeks at a time, that should be something that we talk about more” (P10, wildland firefighter/office role)
	Optimise supports and strategies to increase awareness	“Important to have information on what we’re getting ourselves into and the long-term effects of this job” (P4, wildland firefighter) “The stigma and not really recognizing some of the effects of, you know, exposure and post-traumatic stress” (P6, researcher) “Some education in that area to people in the field would be good. Cause I think a lot of folks are not you know, aware of the mental toll that this job might have…it’s certainly not something that’s discussed as a standard as part of the training” (P10, wildland firefighter/office role)
Stress		“It would be interesting to know of the long-term effects of stress. People, people come and typically fight fire for anywhere between 3 and 5 years and they move on because we recruit really heavily from university students. Once they’re done their degrees they leave. Um, but I do wonder, especially with the seasons of 2017 and 2018, how much is that taken out of people and like, what are the long-term effects of that?” (P10, wildland firefighter/office role) “Um, in terms of having an off-season and kind of being able to, um, recharge, I guess? And avoiding that burn out. So, it will be interesting to see like in the different roles, and in the different timing, um, how that plays into stress. And the other thing that’s come up, is the other work priorities. So, it’s not always just wildfire. And I think some of our additional priorities can contribute to stress, and contribute to chronic stress where, um, there’s a little bit more push for prevention, and a little bit more push for like chainsaw work and training and stuff like that. Like, you know where we’re just sitting waiting for fires, we’re pushed to do work, um we’re pushed to do other work like all the time. And sometimes even just busy work which might play into that kind of chronic stress, fatigue and not really getting to have a break” (P4, wildland firefighter)
Long-term risk and prevalence of disease other than respiratory		“I don’t have a lot of understanding of how the body flushes its stuff out in the winters, but I hope it does. I don’t know, I don’t know [sic] what’s really happening to the body” (P2, wildland firefighter) “But like, seeing the long-term effects of, like even lifespan. I know that’s kind of dark but … But I mean, if someone’s been doing this since they were eighteen kind of thing, it would be interesting to see how one’s been affected… Yeah, their life overall and if they’ve had cancer pop up – not just lung cancer” (P3, wildland firefighter)

PPE, personal protective equipment.