Are nitrates in kosher hot dogs?

Sodium nitrite is actually the chemical added in Hot Dogs, not sodium nitrATE. Sodium nitrite is added to pork and other meat products as a preservative to allow it to remain fairly pathogen-free on its way to distant markets. Not all kosher hot dogs are nitrite-free, so you have to look at the ingredients. Most hot dogs have sodium nitrite, though.

The problem with nitrites is that they are converted to nitrosamines in the body...and nitrosamines are very carcinogenic. The simple reason why we don't get cancer after eating a hot dog is because we have DNA repair and regulation mechanisms in our cells that prevent cancers and DNA damage. However, over time, as damage accumulates, those repair mechanisms break down and become less effective, leading to increased probability of cancer.