en Food Safety and Hygiene Food Safety and Hygiene Review Review Article <p dir="ltr" style="text-align: justify;"><span style="font-size:14px;"><span style="font-family: times new roman;">Agricultural advancement and population growth have prompted increases in food supplies, and higher crop yields have been made possible through the application of fertilizers. Large quantities of livestock and poultry on farms, along with the accumulation of biomass and agricultural residues, can cause contamination of ground water resources and other water sanitation concerns in both developing and developed countries. Nitrate is mainly used as a fertilizer in agriculture, and because of its high solubility in water, it can create biological problems in the environment. High usage of nitrite in the food industry as a preservative, flavor enhancer, antioxidant, and color stabilizing agent can cause human exposure to this toxic compound. Nitrite is 10 times as toxic as nitrate in humans. Nitrate is converted to nitrite and nitrosamine compounds in the human stomach, which can lead to bladder cancer. In this review, sources of nitrate and nitrite exposure were investigated. Furthermore, the review evaluates standard levels of nitrate and nitrite in different foods, and acceptable daily doses of these compounds in various countries. Finally, we discuss valid methods of nitrate and nitrite identification and removal in foods.</span></span><br> &nbsp;</p> Nitrate, Nitrite, Nitrosamine, Contamination Food 80 86 http://jhehp.zums.ac.ir/browse.php?a_code=A-10-26-1&slc_lang=en&sid=1 Sajad Chamandoost jamal_hossini@yahoo.com 10031947532846009310 10031947532846009310 No Department of Health and Food Safety, School of Public Health, Zanjan University of Medical Sciences, Zanjan, Iran. Mohammad Fateh Moradi jamal_hossini@yahoo.com 10031947532846009311 10031947532846009311 No Veterinary Organization of Zanjan, Iran. Mir-Jamal Hosseini jamal_hossini@yahoo.com 10031947532846009312 10031947532846009312 Yes Department of Toxicology and Pharmacology, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran.