That will depend on the type of contaminant.
Potential for lead poisoning
In the food you eat, if it smells it has food poisoning in it
Because cans seems are or where sealed by lead. The lead, after a time, contaminated the contents. This caused food poisoning.
The shape of food poisoning? depends I suppose on what bacteria caused the food poisoning in the first place.
To avoid food poisoning - which could lead to diarrhea, vomiting and fever, or even death if severe enough.
Bacteria contamination and growth which can lead to food poisoning can be eliminated (or reduced)by cooking at the proper temperature for that food.
There is some evidence that ancient, prehistoric peoples who smelted lead and tin suffered from lead poisoning.
Lead poisoning is caused by breathing in lead dust or ingesting lead in some way. Today little children can get lead poisoning if they put something coated with lead, say a toy colored with led paint, in their mouths. They sometimes eat lead chips of brightly colored paint. Adults can get lead poisoning by working with lead in some capacity, such as a person making stained glass, or by eating canned food that was packed in a lead lined can. (Although banned in the United States, lead lined cans for food are allowed in other parts of the world.) As for the relevancy of lead poisoning to ancient Rome, yes, the ancient Romans had the opportunities to contract lead poisoning big time. The pipes leading from the aqueducts to private homes and public fountains were made of lead. (the pipes in the aqueducts themselves were of more durable ceramic) The Romans also literally ate lead. They used lead as a sweetener, especially in wine. Many cosmetics were lead based as were the brightly colored glazes used in their ceramic dinnerware.
yes
the owner of the place you got the food poisoning from
You can get food poisoning at any age if you eat it
Lead is no longer used in food containers because it can leach into food and cause lead poisoning, which can lead to serious health issues, especially in children. The harmful effects of lead on human health have prompted regulations and bans on its use in food containers to protect public health.