The determination of blood nitrite concentration is a direct method for diagnosing nitrite poisoning. By extracting peripheral venous blood samples and sending them to the laboratory for analysis of nitrite levels, it is possible to determine whether there is an abnormal increase in nitrite levels in the body, thereby determining whether nitrite poisoning has occurred.Carcinogenic risk: Nitrite can combine with amines in the body to produce nitrosamines, which have strong carcinogenic effects and mainly cause malignant tumors such as esophageal cancer and gastric cancer. Therefore, monitoring nitrite levels in the blood can help assess an individual's risk of cancer. Cardiovascular disease risk: Although nitrite is beneficial to the cardiovascular system when consumed in moderation (such as dilating blood vessels, improving blood flow, controlling blood pressure, etc.), excessive intake may pose health risks. Therefore, blood testing can be used to understand an individual's nitrite exposure level and assess their cardiovascular disease risk.