Why is the use of nitrite in cured meat controversial?

In the context of meat processing, the use of nitrite is valued for its ability to inhibit the growth of bacteria that cause food poisoning, retard rancidity, and maintain the desirable red or pink color of cured meats.12

However, the use of this additive is controversial due to its potential link to cancer. When ingested, nitrite ions can react with stomach acid to form nitrous acid, which may then react with certain organic compounds to produce nitrosamines. Because some nitrosamines have been shown to cause cancer in laboratory animals, regulatory bodies like the United States Food and Drug Administration impose strict limits on the amount of nitrite that can be legally added to food products. To mitigate these risks, processors often include compounds such as sodium erythorbate or ascorbate, which help decrease the risks associated with nitrite use while further enhancing color development.12