Carbon monoxide (CO) is a highly toxic gas that is produced from the incomplete combustion of carbon-containing materials and can cause illness and death.1 , 2 It is odorless and colorless,1–3 which makes detection difficult without electronic measurement devices.4 Exposure to CO in the United States accounts for an average of 438 fatalities per year, with higher rates in the Midwest.2 In Wisconsin, data routinely captured by the Wisconsin Environmental Public Health Tracking (WI EPHT) Program, a Centers for Disease Control and Prevention (CDC)–funded program housed within the Wisconsin Department of Health Services (WDHS), show that approximately 500 residents visit an emergency department (ED) each year for unintentional CO poisoning incidents and roughly 5 die of unintentional CO poisoning.5 While the majority of CO poisonings happen at home,2 large-scale CO poisonings do occur,6–8 and 5 states—Connecticut, Massachusetts, Minnesota, Pennsylvania, and Rhode Island—have legislation that requires CO alarms in ice arenas and other indoor venues.9
On the second Saturday of December 2014, a hockey player lost consciousness following a tournament in Lake Delton, Wisconsin. First responders detected elevated levels of CO in the arena and identified the source as a propane-fueled ice resurfacer—later determined to be needing maintenance. Emergency management encouraged all attendees and players to seek medical evaluation, resulting in 92 persons seeking care in 4 area EDs. In total, 74 (80%) of these individuals met the criteria for CO poisoning (ie, having a blood carboxyhemoglobin level of >5% for nonsmokers or >10% for smokers)10 and 2 persons had poisoning that required hyperbaric oxygen treatment—a treatment reserved for only the most serious cases of CO poisoning.9
The CO poisoning event in Lake Delton was the largest in Wisconsin's history and highlighted the importance of outreach and surveillance as tools for prevention. While Wisconsin law requires smoke and CO detectors in residences,11 it does not require them in public venues such as ice arenas. As such, not all arena operators may be fully aware of the importance of preventive measures. WI EPHT compiles and publishes data on CO poisoning hospitalizations and ED visits in Wisconsin via our online data portal5—which is used by local public health agencies, public health stakeholders, and the general public. These data have been useful in generating local initiatives. For instance, Burnett County created a community outreach program to distribute CO alarms based on data from the WI EPHT portal, which indicated higher rates of CO ED visits for that community. However, the data on the portal are retrospective and do not identify clusters of mass exposures, which limit their utility for some aspects of surveillance. While the Lake Delton event was large enough to garner national media attention,12 other large-scale CO poisonings may occur without being reported in the media. This article discusses the work done by WI EPHT to improve both outreach on and surveillance of mass CO poisonings in Wisconsin.
Following the Lake Delton CO poisoning event, the WI EPHT Program sought to enhance outreach efforts and improve real-time surveillance of mass CO poisonings in Wisconsin. Both of these avenues were pursued as different means to prevent future large-scale CO poisonings in the state. WI EPHT took the lead in these efforts, utilizing 2 complementary approaches. First, WI EPHT worked to revise existing and create new outreach materials for multiple audiences to better explain symptoms of CO poisoning and means of preventing poisoning. Outreach efforts were assessed by surveying stakeholders to gauge effectiveness. Second, WI EPHT built upon a long-standing relationship with the Wisconsin Poison Center (WPC) to create a real-time system for CO surveillance.
WI EPHT communications staff worked with a WDHS toxicologist to revise existing outreach materials and create new materials for multiple audiences. WI EPHT revised existing recommendations for ice arena owners and operators that explain symptoms of CO poisoning and the importance of adequate ventilation, regular air monitoring, and proper equipment maintenance. The original recommendations, while informative, were technical and not necessarily easy for readers to understand. Using the CDC's Simply Put: A Guide for Creating Easy-to-Understand Materials,13 we used plain language principles, shortened the amount of content, added clearer headings and subheadings, added pictures and graphics, increased white space, and reorganized content strategically. The resulting document is titled Recommendations for Enclosed Ice Arena Management and includes a poster with the signs and symptoms of CO poisoning (Figure). While Wisconsin indoor ice arenas are not required to monitor air quality, it is strongly recommended. As such, we included templates for arena employees to log air quality test results and equipment maintenance for their own records. WI EPHT also created fact sheets for parents and coaches of ice arena sports to illustrate how CO poisoning can occur and offered recommendations for keeping children safe (eg, knowing the signs and symptoms of CO poisoning, taking action when seeing symptoms). Parents of hockey players reviewed draft fact sheets and offered feedback to make the resources as relevant as possible for the intended audience.
A communications plan was developed by WI EPHT staff to guide dissemination of materials. This plan included e-mailing local public health partners, hockey clubs, and ice skating clubs about the new resources, as well as sending a direct mailing to all 91 Wisconsin ice arenas. All the outreach materials generated are available online via the WI EPHT Web site (dhs.wisconsin.gov/epht). In the months following distribution of these materials, WI EPHT conducted a 5-minute telephone survey to determine whether arena operators were using the new materials. Staff members were able to make contact with 84 of 91 ice arenas and either administered the survey or left a message. Callers were instructed to leave only 1 voice mail but to call back 2 more times if the call was not returned. In total, 43 arenas were surveyed. Respondents were asked whether they remembered receiving the materials, whether they made any changes to equipment or policies as a result of the materials, what type of ice resurfacer they use, and whether they have CO detectors in the arena. In the interest of keeping surveys as short as possible, some questions of interest were not included in the survey (eg, questions regarding current air quality monitoring efforts). If a respondent did not receive the mailing or was unsure, WDHS staff offered to resend the outreach materials and confirmed the mailing address on file.
Immediately after the Lake Delton incident, WPC indicated to WDHS that it handled a large volume of calls related to the poisoning the night of the event. If WDHS had received automatic notification of the high call volume, it would have permitted on-call staff to be aware of the event in near real-time. This would have allowed WDHS to offer assistance and resources in a timely manner. Moreover, monitoring of CO-related call volume over time could improve public health surveillance of large-scale CO events. WI EPHT worked with WPC and the National Poison Data System (NPDS) to create real-time alerts that automatically e-mail select WDHS staff members when calls to WPC concerning CO reach predetermined volumes. These alerts are monitored 24 hours a day during regular work hours and by on-call WDHS staff after hours. To this end, 2 different types of alerts were developed: (1) high-acuity alerts, which are triggered when a CO-related case is coded by WPC protocol as having a “moderate” or “severe” effect on the individual; and (2) volume alerts, which are triggered when 2 or more cases cluster together in time (ie, in a 4-hour period).
Of the 84 calls made to ice arenas following distribution of outreach materials, 43 (51%) interviews with ice arena staff were completed. Of the 43 people interviewed, 18 (42%) recalled receiving the mailing. As a result of the mailing, 1 arena operator (6%) said it reevaluated and updated its current air quality policy. Another operator (6%) said it installed CO detectors in the arena for the first time. Nine respondents (50%) noted they did not make any changes because they were already following the recommendations or had electric ice resurfacing equipment that did not generate CO. Thirty-three respondents (77%) said they had CO detectors in the arena, but some of these noted they were designed for home use or were otherwise inadequate for the ice arena setting. After the outreach effort, 3 ice arenas e-mailed WDHS to request advice related to air quality, indicating that more ice arena managers and staff members know the capacity of WDHS to provide technical assistance.
Outreach via the hockey and figure skating associations resulted in improved partnerships and the opportunity to share our materials beyond the borders of Wisconsin. A February 2016 webinar on the CO poisoning event and resulting outreach materials drew an attendance of 70 people across the United States and Canada. The archived recording has been viewed 179 times. In addition, the CDC and the National Environmental Health Association collaborated to feature the outreach materials in a pair of online videos.14 , 15
As a result of outreach efforts, 2 WDHS staff members were invited to participate in a panel presentation on air quality at an April 2016 Wisconsin Ice Arena Management Association conference. Staff gave a synopsis of the Lake Delton CO poisoning event and offered recommendations related to ice arena air quality. Staff handed out postcards with information about available resources. This meeting was attended by a national representative of the Serving The American Rinks (STAR) organization—a national nonprofit membership organization that provides education, resources, training, and events to ice rinks. The STAR representative was pleased with the newly developed materials and featured them in a presentation he gave to the ice arena managers on the dangers of CO.
From their initiation in September 2015 to the time of writing this article (January 2017), the WPC-based alert systems have generated 43 volume alerts from 523 individual cases. Fifty-three high-acuity alerts were also triggered. The highest number of cases in a single-volume alert was 7 and the lowest was 2. Thirty-five percent of volume alerts are related to clusters of 4 or more cases. WI EPHT responded to these alerts on the basis of the established protocol, which is further descried in the “Discussion” section. As yet, none of these alerts have been indicative of any large-scale CO poisoning events akin to the Lake Delton incident.
Instituting the alert system for improved notification and surveillance has involved several iterations and continues to be refined. WI EPHT staff members have worked to develop notifications using existing NPDS tools that contain built-in algorithms. The aim of WI EPHT was to strike the necessary balance between obtaining the relevant information on larger-scale CO events without receiving an unmanageable number of notifications. While the high-acuity alerts trigger for every case that meets the criteria, the volume alerts are dependent on an algorithm and has required calibration to achieve the most efficient results. For example, 1 CO event was detected in which 4 cases were noted by WI EPHT staff but no volume alert was received. Further investigation revealed that cases had been time-stamped at one point but entered into the system at a later point outside the window that the algorithm for the volume alert was searching. Adjustments were made that increased the number of times the algorithm runs during a 24-hour period. These adjustments have subsequently improved the ability of WDHS to detect volume alerts.
WDHS and WI EPHT staff improved CO poisoning prevention outreach and saw a positive response from stakeholders. Ice arena owners and operators were appreciative of the new materials, and one even reported installing a CO detector for the first time. The positive response of STAR—an organization that works to educate and assist ice arenas—to our improved materials was also an encouraging outcome. Finally, 3 ice arenas later contacted WDHS toxicologists for technical assistance and information on CO poisoning prevention. This suggests that WDHS is being viewed as a trusted source of information and that there is an increased awareness of the risk of CO poisoning within the ice arena community.
Despite these successes, it is likely that further outreach efforts will be needed to change behavior of ice arena owners and operators. While many arenas are supportive of improving air quality in their arena, it does present a significant—and sometimes unfeasible—expense for appropriate equipment and staff time to conduct monitoring. To avoid continued air quality monitoring, some arenas might choose to switch to an electric ice resurfacer, which can cost more than $100 000.16 Recommendations for Enclosed Ice Arena Management outlines best practices for optimal safety, but we recognize that staff time and equipment costs required to implement all of the recommendations may present barriers for some ice arenas. Future outreach efforts—along with other resources and partnerships—will be necessary to overcome these barriers.
Alerts generated from CO-related calls to WPC were instituted as a means of improving real-time surveillance of CO poisoning events in Wisconsin. WDHS was not notified in the immediate aftermath of the Lake Delton mass poisoning event, precluding officials from offering technical guidance and assisting with response coordination. With real-time surveillance of poison center calls, WDHS will be able to know when an event is occurring and can offer assistance in a timely manner. WI EPHT also developed a protocol for handling large-scale CO events, which lays out the responsibilities of WDHS epidemiologists and toxicologists. When a volume alert appears to be a large-scale mass exposure, staff will call WPC to confirm the details of the exposure. WDHS can then alert local public health authorities about CO poisoning events and provide technical guidance, environmental monitoring, and coordination assistance as needed. All of this work may serve as a model by which other state health agencies can improve CO poisoning outreach and surveillance to provide technical guidance and coordination assistance to stakeholders.
In the interest of making our survey of ice rinks as short as possible, we did not include questions regarding the current air quality monitoring. Researchers may wish to consider asking questions about this topic in future surveys, as it would be another potential indicator of adoption of best practices. In addition, while it was beyond the scope of the work presented here, it would be interesting to further understand the history behind the regulations in the 5 states that require CO monitoring in ice rinks. The reasoning behind these pieces of legislation may be of use to communities, policy makers, and ice arena owners or operators.
Implications for Policy & Practice
- Public health plays an integral role in preventing large-scale CO poisonings via outreach, education, and surveillance.
- Improved CO poisoning surveillance can help public health agencies rapidly coordinate an appropriate response.
- Creating materials with simple language and graphics that are developed with input from target audiences may improve adherence to public health recommendations.
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