The silent killer in our homes

You can’t see, taste or smell it. You may put your constant headache down to flu or even a bad hangover. Severe symptoms include vertigo, nausea or breathlessness. It’s currently killing around 60 people a year and sending around 4,000 to A&E.

I’m talking about carbon monoxide (CO) poisoning. CO is a colourless and odourless gas that’s produced when carbon-based fuel is incompletely burnt. Normally our red blood cells deliver oxygen to our heart, brain, vital organs and the rest of the body. But CO binds 240 times more strongly to the red blood cells, displacing oxygen with potentially lethal consequences.

Exposure can occur in confined spaces with poor ventilation, particularly in winter with closed windows and heating. Add a poorly installed, faulty or badly maintained gas boiler, heater or cooker and you are at risk. Other sources include portable generators, blocked chimneys and clogged car exhausts.

Years ago I had radiators installed in summer and was advised to leave the heating on for 24 hours. I woke with a headache and nausea. Later,

I realised an open window had been funnelling fumes from the flue into my bedroom. By then I’d turned it off and recovered. Others are not so lucky.

The trouble is low-level CO poisoning is difficult to identify. Brief exposure may feel like food poisoning or flu with headaches, nausea and dizziness. Over 30 per cent of people are likely to mistake the symptoms of CO poisoning as something else.

Most people recover from low-level CO poisoning, though children, pregnant women, the elderly, those with heart or respiratory diseases are more vulnerable to complications.

With chronic low-level exposure symptoms appear more slowly. You may also suffer from irritability, memory issues, respiratory and heart problems – yet these are often attributed to other causes.

Exposure to higher levels of CO leads to more acute symptoms such as confusion, shortness of breath, heart attack, weakness, loss of consciousness or even death.

Signs to look out for…

Other people in your home fall ill with similar symptoms.

When you change location symptoms clear but return when you’re back.

Symptoms get worse in winter. Your pets also become ill. Gas-powered appliances develop yellow or orange flames rather than blue, you see an increase in soot or yellow-brown staining, the pilot light frequently blows out, there is more window condensation or smoke builds up in rooms.

To stay safe, have appliances serviced regularly by a Gas Safe

Registered engineer and ensure proper ventilation. Install a CO alarm (try fireangel.co.uk). Never use ovens to heat your home, or sleep in a room with a gas fire without a flue.

If you’re concerned about a leak, get into fresh air and phone the emergency line: 0800 111 999. If you suspect exposure, seek medical advice. If concerned about high levels, go straight to A&E. They can measure your CO levels, give you high-dose oxygen therapy and check for complications.

Carbon monoxide poisoning affects thousands of people every year