Activity: Drag and drop to correctly complete each statement in the left hand column. Foodborne illness is caused by: Chemical contamination occurs when food is contaminated by: Physical contamination occurs when food is contaminated by: Biological contamination occurs when food is contaminated by: Most foodborne illnesses are caused by: cleaning products, pesticides and herbicides from unwashed fruit and vegetables. contaminated food. biological contamination. bacteria or other microorganisms. glass, staples, hair, bandages insects.