Salivary lead and cadmium in a young population residing in Mexico city

Mexico city has a very high pollution index. Based on the view 'that salivary monitoring can be extended to environmental pollutants', we performed this study in order to determine not only the concentrations of lead and cadmium in human saliva, but also to establish their possible association with some socio-demographic factors. One hundred dental students from the National Autonomous University of Mexico living in Mexico city participated in the study. Stimulated human whole saliva samples were analyzed by atomic absorption spectroscopy. The results show that Pb (x = 3.10 microg/dl(-1); maximum x = 16.8 microg/dl(-1) and minimum x = 0.04 microg/dl[-1]) and Cd (x = 0.25 microg/dl(-1); maximum x = 2.04 microg/dl(-1) and minimum x = 0.004 microg/dl[-1]) concentrations were higher than those reported elsewhere, and that there was no association between several variables studied (age, gender, geographic area and consumption of canned food) and salivary Pb. However, an inverse association was found between Cd and age (chi2 = 5.9012; P < or = 0.05; gamma = -0.5224, P < or = 0.05). From this study it can be concluded that saliva has potential as a technique for monitoring ambient pollutants recent exposure, since circulating levels of certain polluting chemicals can be transported into salivary glands and secretions.