Which of the following is the main reason why carbon monoxide is harmful to humans?

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Question

Which of the following is the main reason why carbon monoxide is harmful to humans?

Accepted Answer

It combines irreversibly with haemoglobin, reducing oxygen transport — Carbon monoxide binds to haemoglobin with a much greater affinity than oxygen, forming carboxyhaemoglobin. This reduces the blood's ability to carry oxygen to body tissues, which can be fatal. Options A, B, and D describe incorrect mechanisms not associated with CO toxicity at IGCSE level.

Answer

It combines irreversibly with haemoglobin, reducing oxygen transport

Answer

It dissolves in lung fluid to form carbonic acid

Answer

It reacts with ozone in the lungs to produce toxic compounds

Answer

It stimulates excess mucus production in the airways

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