Carbon monoxide: the silent killer

The problem with carbon monoxide is that it has no smell, no taste and no colour. What's more, symptoms of mild poisoning - poor concentration, feeling sick, general weakness - are very nonspecific. 

Recently, after 25 years as a GP, I diagnosed carbon monoxide poisoning in a patient for the first time. But that doesn't mean it's the first time I've ever seen it. In fact, even coroners may have difficulty diagnosing carbon monoxide poisoning as a cause of death - which means the figures of 50 people killed and 200 seriously injured every year in the UK could be a significant underestimate. By coincidence, just a few days later, my encounter coincides with an invitation I've been delighted to accept, to work with a national campaign to raise awareness of the dangers of carbon monoxide.

In the USA, a study found 50,000 Americans attend A&E departments every year with possible carbon monoxide poisoning - much higher than previous figures (1). Official US estimates put the figures at 480 deaths and 15,000 hospital attendances a year. In the UK, a study in 2011 suggested 83 people in London were poisoned by carbon monoxide - nearly as many as the official figures for the whole of England in that year. And between May and September 2014, the National Grid says it was called out to 9,500 cases related to carbon monoxide poisoning.

Earlier this year, the Gas Safety Trust in England and Wales confirmed funding for a pilot study, allowing coroners to test for carbon monoxide poisoning in patients going for post-mortem exams. This may help us get a better handle on the real figures - but it's too late for sufferers. What we really need is for everyone to take simple steps to stop it happening in the first place.

The problem with carbon monoxide is that it has no smell, no taste and no colour. What's more, symptoms of mild poisoning - poor concentration, feeling sick, general weakness - are very nonspecific. All sorts of medical issues, including viral infections and dehydration, can give rise to the same clinical picture. In more severe cases, symptoms include unsteadiness, palpitations, rapid breathing, dizziness, confusion, seizures and collapse. The 'cherry red skin' quoted so often in detective novels is actually rarely seen. It works by binding with red blood cells far more effectively than oxygen molecules, depriving body tissues of vital oxygen.

Carbon monoxide is produced when fuels (gas, coal, charcoal, wood, oil) don't combust fully. That means that poorly fitted or unserviced cookers and boilers are the main sources. In summer, barbecues used in enclosed spaces (even if they seem to have gone out) are a major hazard.

The messages for prevention are clear:

  • Always fit a carbon monoxide monitor in your home
  • Make sure your carbon monoxide monitor shows a British Standards Kitemark or Loss Prevention Certification Board logo
  • Get gas fires fitted by a qualified, registered engineer. The same goes for boilers and cookers
  • Get flues and chimneys checked and cleared regularly
  • Service your boiler and cooker regularly
  • Never use barbecues in garages or tents.

It can be tempting to save money - surely a bit of DIY won't do any harm? In fact, where carbon monoxide is concerned, you could literally be counting the cost in lives.

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.