Urban runoff is a major source of nitrate pollution in rivers, posing significant risks to environmental health and public safety, especially in densely populated cities [1]. Additionally, due to the aging process used to make cigars, cigar tobacco contains high concentrations of nitrogen compounds, including nitrates [2]. When ingested, nitrate can react with amines and amides to form N-nitroso compounds (NOCs), which may cause cancer in humans [3]. It is known that salivary glands actively concentrate plasma nitrate into saliva, leading to salivary nitrate levels about 10 times higher than in plasma [4]. Considering that urban or smoker populations might have higher nitrate exposures, we hypothesized that such exposure could be detected through increased salivary nitrate levels. Twenty-one saliva samples were collected in Portugal, comprising 11 samples from rural residents (3 non-smokers and 8 smokers) and 10 from urban residents in Lisboa (5 non-smokers and 5 smokers). After centrifugation and dilution, nitrate levels were determined based on a previously established method using UV spectrophotometry [5]. Mann--Whitney tests were performed to assess differences between groups. Data analysis by rural/urban residence showed no significant difference (p>0.05), with similar salivary nitrate levels: 4.36±0.28 and 4.40±0.26 mg/L in rural and urban populations, respectively. Similar results (p>0.05) were found when considering smoking as a factor, with 4.45±0.36 mg/L in non-smokers and 4.42±0.46 in smokers. These findings suggest that salivary nitrates do not reflect nitrate exposure due to urban living or smoking, or that nither factor substantially increases nitrate body burden. As this study is preliminary, further research with a larger sample is needed for clarification.