1. Processed Meat: Processed meats like ham, sausage, hot dogs, and bacon are widely consumed but pose a risk to human health.

Nitrites added during processing can combine with proteins to form highly carcinogenic nitrosamines. Long-term intake of nitrosamines increases the chances of developing stomach and colorectal cancer.

2. Moldy Food: Moldy food can potentially contain aflatoxins, which are highly toxic and carcinogenic. Even low doses of aflatoxin can induce organ cancer. 

It is important to promptly discard moldy corn, peanuts, nuts, and fruits to avoid potential health risks. 

3. Barbecued Food: Barbecued foods contain carcinogens like benzo(a)pyrene (BaP).

Prolonged intake of BaP increases the risk of developing stomach, colon, lung, and other cancers.