Nicole Wilson, age 10, of Portland, Ore., for her question:

WHAT IS BOTULISM?

Botulism is a type of food poisoning. It is caused by a poison produced by bacteria called Clostridium botulinum. These bacteria live in the soil and grow only where there is no oxygen. They produce cells called spores that can survive the temperature of boiling water for many hours.

The dangerous spores may live in improperly canned foods. If the canned food lacks oxygen, the spores become bacteria and secrete botulinus toxin into it. This toxin, or poison, is one of the most dangerous substances known. It is absorbed by the human intestine and carried to the nerves, where it may cause a type of paralysis.

Modern canning methods have made botulism rare in the United States and Canada.