Food contamination can occur through several pathways:
1. Biological Contaminants: These include bacteria, viruses, parasites, and fungi. Common examples are *Salmonella*, *E. coli*, and *Norovirus*. 2. Chemical Contaminants: These include pesticides, heavy metals like lead and mercury, and industrial chemicals. 3. Physical Contaminants: These include foreign objects like glass, metal shards, and plastic particles.