NEHA November 2022 Journal of Environmental Health

18 Volume 85 • Number 4 A D VANC EME N T O F T H E SCIENCE CO detector had gone o . Of those, 5 did not remember what actions they took after the alarm, 6 responded that they went outside, and 2 indicated that they checked the CO level and got a new heater. Discussion and Conclusion Though our survey was completed by a convenience sample, the respondent characteristics were similar to those of fishers nationally, of whom 73% identify as male and the mean age is approximately 43 years (U.S. Fish and Wildlife Service, 2012). Our results demonstrate that the use of propane heaters in ice fishing is common among those in icehouses. The use of a propane heater can greatly increase the risk of CO exposure, especially if the heater used is not rated for indoor use. CO is, therefore, a real threat to the safety of the ice fishing community. As such, it is reassuring that the majority of people participating in our survey had at least a basic awareness about the dangers of CO in general (92%) and knew at least some of the symptoms of CO poisoning (84%). It is also reassuring that 85% of the ice fishers in our survey reported they would at least go outside of their icehouse if they developed any symptoms of CO poisoning. This rate parallels the 75% of individuals who recalled leaving their icehouse when their CO detector went o . Unfortunately, only 34% of the respondents reported that they would seek medical treatment if they developed CO poisoning symptoms, which is an area that could be improved with broader public education. Moreover, it is clear that the safety of the public could be improved by the promotion of CO detectors in icehouses. Most newly manufactured icehouses carry a warning sticker regarding the CO hazard, but older and homebuilt icehouses likely do not have these warning stickers in place. There is currently no law in Minnesota or elsewhere to our knowledge that requires CO detectors to be installed in icehouses (Minnesota Department of Natural Resources, 2019). Though victims of prior accidents have pushed for legislation, the dangers of CO poisoning and the motivations for change seem to be highlighted publicly only after newsworthy accidents occur (Associated Press, 2017; Davis, 2017; Hudson, 2017; Ross, 2016; Seifert, 2020). Along with proper ventilation and use of portable heaters, the use of CO alarms is considered to be a best practice for the prevention of CO poisoning (Minnesota Department of Natural Resources, 2019). The best CO detector for an icehouse currently is unknown, and further research would be beneficial. Current household detectors operating under UL 2034 standards will alarm when a time-weighted level of CO is detected. In the vicinity of a relatively small area, such as a typical icehouse, the buildup of CO could occur rapidly and thus place fishers at risk before the detector can go o . The alarm on “low-level” detectors, however, will go o when they sense even small amounts of CO, such as those as low as 5 ppm. Indoor-rated propane heaters typically contain an oxygen detection system that will shut the heater o if the oxygen level in the room falls to a point where incomplete combustion will occur, thus producing high levels of CO. Even in normal levels of atmospheric oxygen, however, these heaters still produce CO in the range of 12–46 ppm (Tucholski, 2002). Because of this typical CO production, a “low-level” detector would probably prove to be unhelpful. In our study, only 30% of the respondents answered that they have CO detectors of any type in their icehouse. Broad public education regarding risks and prevention of CO poisoning as well as legislation mandating the use of detectors could make a substantial impact on prevention of CO poisoning (Minnesota Department of Natural Resources, 2019; Minnesota Department of Public Safety, 2019; Steil, 2017). In addition, further research is needed to determine the most appropriate types of CO detectors for at-risk settings more generally. Our results also highlight the significance of alcohol consumption while ice fishing, which is highly prevalent with >77% of the respondents stating that they do consume alcohol while ice fishing. This finding is problematic for several reasons. First, the e ects of alcohol in the bloodstream can impair judgment, placing a person who is ice fishing at increased risk due to an inability Infographic of Survey Data Collected From Ice Fishers Note. CO = carbon monoxide. Drinking While Ice Fishing (79%) @ Average Fishing Time: 9.6 hr iii fiiiii ttttiitiiti fff ffttii ffffffffffi iii fffffi Ifiiiiiiiii ifi iiiiii iiiiiiiiiii iii iiiiii titiiiiiiii Men and WomenWho Fish in Icehouses WITH Propane Heaters (83%) WITH CO Detectors (28%) WITHOUT CO Detectors (55%) Fish Outside FIGURE 2