CO-poisoning cases continue to occur despite being a preventable and well-known consequence of disaster-related power outages.4,6
After this ice storm, CO poisoning was the leading cause of storm-related deaths, surpassing other common causes such as hypothermia and cardiac events.
Kerosene heaters were the most common source of CO poisoning; however, the majority of deaths and severe poisoning cases during this period were associated with generators, which is consistent with a previous study reporting more severe poisoning with generators.6
Even when generators were used outdoors, CO poisoning has occurred when the generators were placed ≤7 feet from the home.4
A community needs assessment conducted in severely affected areas of Kentucky after this storm determined that use of generators and alternative heating sources was common. In three surveyed areas with widespread power outages, 44% to 56% of households had used a generator since the storm, and 4% to 6% of them reported use of a generator indoors or in a garage; 35% to 43% of households had used a charcoal or gas grill, 21% to 36% of whom reported using it indoors (Unpublished data, Community Assessment for Public Health Emergency Response conducted by KDPH and CDC, February 6–9, 2009).
Shelters in the surveyed areas offered services to the population for varying periods after the storm. The community needs assessment was a door-to-door survey of people in private residences, which would eliminate people who remained in shelters or who left the area to stay with family or friends. This might partially explain the high percentage of households reporting use of generators or alternative heating sources.
Lack of education about CO poisoning might contribute to high-risk behaviors. After four major hurricanes in Florida in 2004, less than 50% of adult respondents involved in CO-poisoning incidents related to generator use reported having received instruction in safe operation of the generator.12
Studies have also demonstrated that people are often unaware of the dangers of operating CO-producing devices indoors or near homes.13,14
The number of CO-poisoning cases varied, as expected, with temperature, power restoration, and ice accumulation. The highest rates of CO poisoning were observed in the western part of Kentucky, which -experienced the most ice accumulation and, therefore, the most extensive power outages. These findings support the belief that inclement weather causing widespread power outages increases high-risk behavior among the affected population, thereby increasing the number of CO exposures.
This investigation also determined that people from minority groups disproportionately suffered from severe CO poisoning. Eighteen (47%) of 38 people who died or were administered HBOT were members of racial/ethnic minority groups, whereas across Kentucky, only 10% of the population are members of racial/ethnic minority groups.15
One death and five HBOT cases among minority individuals were caused from burning charcoal indoors, which has previously been described among minority and immigrant groups and has been attributed to language and cultural factors.9,16,17
A study of CO-poisoning cases after a windstorm in Washington State in 2006 determined that all eight deaths were in minority immigrant households; six were associated with improper generator use and two with indoor charcoal use.16
A retrospective review of CO-poisoning patients in Washington State who had been administered HBOT during a nine-year period demonstrated that the relative risk of severe CO poisoning was elevated among black and Hispanic individuals, compared with non-Hispanic white people.17
In response to the CO-poisoning cases, KDPH issued news releases and public service announcements, distributed fact sheets, and activated a person-to-person network to contact members of vulnerable groups such as the elderly, people with hearing impairments, and people living in remote areas. The Kentucky National Guard was mobilized for house-to-house welfare checks and other assistance. In coordination with CDC and a mobile telephone provider, a mass text message regarding CO poisoning was sent to Kentucky customers.
One limitation of this analysis was that certain severely affected areas were without both landline and mobile telephone service for days after the storm, which might have decreased the number of CO exposures reported to KRPC. Additionally, transportation was difficult because of icy roads and downed trees and power lines, which might have prevented people from seeking medical attention. Therefore, data presented in this article might underestimate the true number of affected people. Also, individuals might be included in more than one dataset; therefore, the numbers of CO-poisoning cases from each dataset cannot be summed to provide a total.
The hierarchy of controls indicates that engineering interventions (e.g., generator emission controls and CO-alarm installation) might be more successful than other types of interventions at decreasing CO-poisoning cases. Electronic fuel injection or catalytic after-treatment might decrease CO-poisoning cases from generators by reducing the level of CO in the generator exhaust.18
Two manufacturers of marine generators voluntarily incorporated catalytic converters to decrease CO poisonings on houseboats,19
and similar measures have been suggested for portable generators.5,20
Weatherization of generators by incorporating a waterproof housing, receptacle covers, and ground-fault circuit interrupter protection might lessen the risk for electrocution and make outside generator use easier.18
Because no consensus has been reached regarding a safe distance from a home for operating a generator, CDC recommends placing the generator as far from the home as possible.4
A recent study by the National Institutes of Standards and Technology determined that generators should be placed more than 25 feet from a one-story house to avoid CO entry related to airflow patterns.21
Generators should be sheltered to prevent water damage and electrocution, and connected by using an extension cord rated for outdoor use. They may be secured with lock and chain to prevent theft. Vendors should be encouraged to offer these items along with CO alarms at the point of sale; ideally they should be displayed alongside the generators. Even with these recommendations, people might not comprehend the dangers of operating a generator in a garage, on a porch, or in a basement; therefore, unsafe practices should be specifically addressed in prevention messages.
CDC recommendations for using generators and other CO-producing devices include installing a CO alarm that is battery operated or has battery backup. Prevention messages should stress that it is critical to adhere to manufacturer recommendations and provide adequate ventilation for CO-producing heaters, and should also emphasize that unconventional heating sources (e.g., charcoal briquettes or gas stoves) are unsafe.
Given the lack of knowledge concerning CO poisoning and use of CO-producing devices, educational interventions might also be helpful. Evidence indicates that intensive public education before and after a storm can decrease CO poisonings, especially among minority groups.22
Because of challenges in communicating with people without electricity and because CO poisonings have been documented as early as nine hours after a storm,9
dissemination of prevention messages should begin before storms whenever possible. Messages disseminated after storms should begin immediately, because the majority of CO-poisoning cases after storms occur on days two and three,5
and should use multiple forms of media to reach people without electricity (e.g., radio, fact sheets, door-to-door campaigns, and mobile telephone text messages).