Carbon monoxide poisoning: the deadly indirect effect of severe storms
Next month, the Consumer Product Safety Commission will vote on rules to make recovery from severe weather and associated power outages safer
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Hurricane season is getting underway after a summer punctuated by severe storms across the country. Severe weather, whether from hurricanes or frigid winter storms, can cause all kinds of damage and problems, including power outages.
In February of 2021, a record-setting winter storm hit Texas, damaging electrical infrastructure and rendering millions without power for days. Over 200 deaths were attributed to the storm, both as direct and indirect effects of the cold. One of those indirect causes was carbon monoxide poisoning—over 300 cases, including two fatalities, were reported in Harris County, Texas alone.
Storms and carbon monoxide poisoning
If a storm knocks out power for a few hours, for most people, it’s an inconvenience. But when residents are without power for days on end, it can be quite disruptive to modern life—particularly if they’re dealing with other damage from a storm. So you can’t blame people for doing what they can to get a bit of electricity, if only to charge their phone, plug in a fan, or run a space heater.
Portable generators are an easy way to get electricity to power the essentials during an outage. These generators, which can be purchased for a few hundred dollars at a hardware store, generate electricity by burning fuel, which releases emissions. One chemical these generators emit is carbon monoxide (chemical name CO).
Carbon monoxide is scary because you can’t smell it or see it, yet inhaling too much of it can kill. CO is toxic because it binds to hemoglobin, the protein in our red blood cells that carry oxygen from our lungs to the rest of our body. When CO is attached to hemoglobin, it has such great affinity for it that oxygen can’t attach, which means oxygen can’t reach the rest of the body. (Learn more about carbon monoxide poisoning here.)
The key to avoiding CO poisoning is to make sure that anything emitting the chemical is very well ventilated to the open air, since levels of carbon monoxide can build up in enclosed spaces. Basic generator safety says not to use them indoors or even partially enclosed areas so levels of the gas don’t build up. Even running them near doors and windows can lead to CO buildup inside, so it’s recommended that they be placed as far away from any indoor space as possible—at least 20 feet—when running.
Studying the link
There have been numerous reports of “epidemic CO poisoning” following storms or other disasters, and the majority of cases are associated with use of portable electrical generators. It’s intuitive that there’s a cause-and-effect relationship here: storms lead to power outages, power outages lead to generator use, and generator use leads to cases of CO poisoning.
Considering these storms and disasters are randomly timed as far as health outcomes are concerned, any increase in cases of accidental CO poisoning above the day-to-day levels can be reasonably attributed to the storm.
Having seen this epidemic of CO poisoning during the Texas cold snap, we wondered: was this a fluke, or are storms and associated power outages leading to CO poisoning in a systematic way? And if so, to what extent does the typical storm and outage increase risk? In a paper published in the New England Journal of Medicine in 2022, we (along with economist Michael Kearney and
) turned to the data.We started with data on major power outages, which utilities must report to the Department of Energy if they impact a large number of households. Overall, 87% of these major outages were associated with severe weather, and they were roughly split between summer and winter storms (though June had the most major outages). We then linked those outages to insurance claims data in the same time and region, looking for cases of carbon monoxide poisoning that required medical care from 2007-2018. Here’s what we found:
When the power outages were short, lasting less than 24 hours, we didn’t see any increase in cases of CO poisoning during the outage compared to the 10 days preceding and following. But as outages lasted longer, we started to see increases in cases of CO poisoning. For outages lasting longer than 48 hours, there were 9.3 times as many cases of CO poisoning compared to baseline on the third day of the outage—for children, who are more susceptible to CO poisoning, there were 13.5 times the number of cases.
What to do
Our study looking at major outages in a systematic way over a 12 year period, suggested that these outages—the large majority of which were associated with severe weather events—lead to cases of CO poisoning, helping to confirm what a review of individual CO poisoning outbreaks would suggest.
How can we prevent these power outage related cases of CO poisoning?
Step 1 would be to prevent power outages in the first place—which means shoring up our aging electrical infrastructure to be able to withstand the severe weather events that are expected to increase in frequency and severity in the coming decades with rising global temperatures.
The next steps are to ensure that if people do generate their own power using generators, that they are equipped to do so safely. This means owners need to be aware of the steps they need to take to operate the generator safely—including ensuring that carbon monoxide detectors in the home have a battery backup so that they still work during a power outage.
Experts Drs. Fred Henretig, Diane Calello, and Kevin Osterhoudt emphasize the need for safer generators—here’s what they wrote after seeing our study:
Most such generators produce large amounts of carbon monoxide — amounts similar to that produced by more than 400 simultaneously idling late-model cars. However, generators built with modern emission controls that greatly reduce carbon monoxide emissions and incorporate additional safety features such as automatic shutoff valves for high ambient carbon monoxide concentrations are currently available. Although the authors’ suggestion to invest in electric grid infrastructure to help prevent power outages is reasonable, we would underscore the need for immediate strategies, such as guiding purchasers of new generators toward such safer models and educating the public on safety regarding portable generators.
Seeing mounting evidence of the dangers of portable electrical generators, as highlighted during the Texas cold snap, the Consumer Product Safety Commission took action this year.
In April, the CPSC (which is perhaps best known for safety recalls on various products for babies and children) issued a new rule mandating that portable electric generators emit less CO and have CO detection/automatic shutoff systems built in. They estimate that over the next decade, such a rule will save 2,100 lives, prevent 126,000 non-fatal poisonings, and save $1 billion in costs related to these poisoning cases.
The mandate—which has faced pushback from generator manufacturers saying they are already working toward safer products—goes up for a final vote at the CPSC next month. Regardless of how we get to safer generators, what’s clear is that families, emergency responders, and medical personnel who are already strained during storms and power outages shouldn’t have to face the additional burden of CO poisoning. With the chances of severe weather and power outages on the rise, demand for portable generators is at an all time high—let’s make sure they’re safe.