Desenvolvimento de métodos espectrométricos e voltamétricos para avaliação crítica do teor de metais tóxicos presentes no cigarro e na fumaça inalada considerando-se aspectos de bioacessibilidade pulmonar

Abstract

Smoking is a public health problem and an important source of exposure to toxic metals that affects a significant part of the world population. The search for analytical data on toxic elements in cigarettes is still a matter of current analytical interest, since not all substances present in tobacco have been well identified and also due to their relatively high consumption. In this context, the objective of this study was to develop strategies for characterizing the profile of trace elements in the different constituent parts (pre and post-burn filter, tobacco, ash and smoke) of cigarettes illegally sold in Brazil using the graphite furnace atomic absorption spectrometry (GF AAS) and square wave voltammetry (SWV). The samples, considered illegal according to the Fumigant Product Registry of the National Health Surveillance Agency, were purchased from the local shops of Juiz de Fora-MG and Conselheiro Lafaiete-MG, totaling 12 different brands of illegal cigarettes. The instrumental parameters for the determination of Pb and Cr by GF AAS and Cd, Pb and Cu by SWV were investigated. Different sample preparation methods were developed, using microwave assisted digestion. The methods showed adequate results regarding precision (RSD <7% for GF AAS and <11% for SWV) and accuracy (average recoveries of 97.6% for GF AAS and 89.3% for SWV). Accuracy was also evaluated using a reference sample of tomato leaves (NIST SRM 1573a), which proved the efficiency of the method (recoveries of 103% for GF AAS and 95% for SWV). The detection limits were less than 1.72, 1.33 e 2.07 μg g-1 for Cd, Pb and Cu, respectively, while for Cr they were below 80.7 ng g-1 . Regarding the analytical results, the average values of chromium found for the analyzed samples ranged from 0.96 to 3.85 and from 0.32 to 0.80 μg/cigarette for tobacco and ash, respectively. For most pre-burn and post-burn filter samples, the chromium concentration values remained below the detection limits. The cadmium content remained below the detection limits, while the average values found for lead ranged from 0.10 to 0.38 μg/cigarette (post-burn filter), from 0.89 to 4.85 μg/cigarette (ash) and from 1.76 to 9.92 μg/cigarette (tobacco). The average values found for copper were in the range of 0.20 to 0.83 μg/cigarette (post-burn filter), from 1.30 to 7.45 μg/cigarette (ash) and from 7.24 to 43.1 μg/cigarette (tobacco). The smoke samples collected had their Pb and Cu levels quantified by SWV with average concentrations ranging from 0.12 to 0.43 and from 0.05 to 1.47 µg/cigarette for lead and copper, respectively. The bioaccessible fraction of these metals in smoke was also studied. Gamble's solution was used as a simulated pulmonary fluid, being possible to quantify only copper. The average concentration of copper soluble in the simulated lung fluid ranged from 0.09 to 0.67 µg/cigarette. In general, the data indicate that tobacco is the main source of toxic metals in smuggled cigarettes. The results obtained can be considered high and worrying, in view of the exacerbated consumption that triggers serious health problems for consumers and high rate of waste generation (smoke, filters and ashes) causing also environmental contamination.