Poisonings and injuries related to carbon monoxide exposure: data blog:

This data blog presents statistics on unintentional poisonings and injuries related to carbon monoxide (CO) exposures captured in the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) between April 1, 2011 and June 15, 2023. CHIRPP is a sentinel surveillance system capturing injuries and poisonings presenting in 21 emergency departments across Canada. Every year, approximately 170,000 injury and poisoning records are entered in the database, from which information, such as the circumstances and types of injuries can be examined. This data blog then concludes by providing important prevention safety measures to reduce the risks of being exposed to CO.

How is carbon monoxide produced?

CO is produced when hydrocarbon fuels such as charcoal, wood, gasoline, natural gas or propane are burned incompletely. The poor maintenance, installation and ventilation of fuel burning appliances and equipment, such as fireplaces, gas ovens and generators can lead to the dangerous buildup of CO gas in indoor spaces, including kitchens, garages and living rooms.

Be aware of the symptoms of CO poisoning^{Footnote 4Footnote 5}:

The early signs of mild to moderate CO poisoning are similar to the flu or food poisoning (except no fever), and some common symptoms include:

• Headache
• Shortness of breath
• Fatigue
• Dizziness
• Nausea

Higher levels of CO poisoning can, however, lead to worse and life-threatening symptoms, including:

• Vomiting
• Loss of consciousness
• Coma
• Death

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Carbon monoxide-related cases in CHIRPP

As presented in Table 1, between April 1, 2011 and June 15, 2023, there were 767 unintentional CO-related events reported in the CHIRPP database, representing 42.6 cases per 100,000 CHIRPP records. Of these events, the mean age was 17.5 years; males represented 55.1% of cases (n = 423), and children aged 0 to 4 years represented the highest percentage among age groups at 24.3% (n = 184). Nearly two-third of cases (63.6%) occurred during the colder seasons of Canada: fall and winter. Work-related incidents involving CO exposure accounted for 10.6% of cases (n = 81). There were 150 incidents that resulted in two or more patients presenting in the emergency departments – these incidents involved 458 patients in total.

Table 1. Characteristics of carbon monoxide-related cases in CHIRPP, April 1, 2011 to June 15, 2023:

Table 1. Characteristics of carbon monoxide-related cases in CHIRPP, April 1, 2011 to June 15, 2023.

Characteristics		Count	Proportion (%)
Sex	Male	423	55.1
	Female	344	44.9
Age group (years)*	0 to 4	184	24.3
	5 to 9	148	19.6
	10 to 14	140	18.5
	15 to 19	69	9.1
	20 to 29	59	7.8
	30 to 39	45	5.9
	40 to 49	45	5.9
	50+	67	8.9
Season**	Winter	296	38.6
	Spring	192	25.0
	Summer	96	12.5
	Fall	183	23.9
Work-related incident	Yes	81	10.6
	No	686	89.4
* 10 cases had missing age. ** 3 cases had missing injury dates.

Emergency department presentations and outcomes

Among all cases, poisoning and asphyxia/threat to breathing were the most common emergency department presentations at 85.7% (n = 655). Of note, among 12.1% of cases (n = 93), no injuries or poisonings were detected following assessments at the emergency departments. In terms of outcomes, the majority of patients required observations and treatments in the emergency departments at 37.1% and 31.9%, respectively. Approximately 6.9% of patients were admitted to the hospital (Table 2).

Table 2. Characteristics of carbon monoxide-related emergency department presentation in CHIRPP, April 1, 2011 to June 15, 2023:

Table 2. Characteristics of carbon monoxide-related emergency department presentation in CHIRPP, April 1, 2011 to June 15, 2023.

Characteristics of emergency department presentation		Count	Proportion (%)
Type of injury/poisoning	Poisoning	569	74.2
	Asphyxia/threat to breathing	86	11.2
	No injury detected	93	12.1
	Other injuries	19	2.5
Treatment*	Observation in emergency department	284	37.1
	Treatment required at emergency department	244	31.9
	Advice only provided	179	23.4
	Admitted to hospital	50	6.5
	Left without being seen	7	0.9
	Death	2	0.3
* 1 case had missing information on treatment.

Source of carbon monoxide exposure

Where reported, vehicle emission, smoke/fire and barbecues were the most common sources of CO exposure reported, accounting for over one third of identified cases (Table 3).

Table 3. Carbon monoxide-related poisonings and injuries by source in CHIRPP, April 1, 2011 to June 15, 2023:

Table 3. Carbon monoxide-related poisonings and injuries by source in CHIRPP, April 1, 2011 to June 15, 2023.

Source	Count	Proportion (%)
Vehicle emission	108	14.1
Smoke/fire	101	13.2
Barbecue	58	7.6
Furnace	49	6.4
Machinery	36	4.7
Oven/stove	32	4.2
Unspecified gas leak	30	3.9
Fireplace/wood stove	19	2.5
Generator	19	2.5
Propane heater	13	1.7
Propane source (other)	10	1.3
Other	9	1.2
Not reported	283	36.9

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Statistics from the Consumer Product Safety Program- Health Canada

From June 20, 2011, to February 28, 2023, the Consumer Product Safety Program received 49 reports involving unintentional CO poisoning. Among the 49 reports, 43 described events in Canada. These reports also noted 34 instances of reported fatalities and 15 reported injuries related to CO poisoning.

The top 3 product categories reported include:

• Kitchen appliances (n = 15)
• Heating and cooling appliances (n = 13)
• Generators (n = 12)

Additionally, there are approximately 150 possible cases of CO poisoning reported from media sources. Due to limited information available in these reports, involvement of CO poisoning is suspected but could not be confirmed and location will vary.

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Prevention: Reduce the risks of carbon monoxide exposure

CO poisoning is preventable. Below are some important safety measures that may help reduce the risks of being exposed to CO:

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Take Action: What to do if you suspect CO exposure

1. Evacuate the property immediately and move to an area with fresh air.
2. Call 9-1-1 without delay.
3. Do not go back inside. Wait for the approval of emergency services responders before re-entering the premises.

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Limitations

The results presented above do not represent all CO-related injuries and poisonings in Canada. CHIRPP is a sentinel surveillance system that collects data from select emergency departments across Canada. Injuries involving Indigenous peoples including Inuit, Métis and First Nations and people who live in rural areas may be under-represented in the CHIRPP database, as most CHIRPP hospital sites are located in major cities. Fatal injuries are also under-represented in the CHIRPP database as the emergency department data do not capture deaths occurring before being taken to the hospital or after being admitted via another department. Information is continuously entered into the CHIRPP database; therefore, some years may not have complete data.

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