Dottorato in SCIENZE CHIMICHE

Titolo della tesi: QUANTITATIVE DETERMINATION OF EXPOSURE AND EFFECT BIOMARKERS IN THE ASSESSMENT OF EXPOSURE TO HAZARDOUS SUBSTANCES IN WORK AND LIVING ENVIRONMENTS

Human biomonitoring, considered a complementary method to environmental monitoring, in recent years, has become a valuable mean to assess occupational and environmental exposure to chemicals. In fact, biomonitoring data reflect the dose taken up by the organism through all routes of exposure, the variability between different individuals in the level of exposure and the ability of the organism to metabolize and excrete the chemical. The main focus of this PhD project was the study of the relation between human exposure to dangerous substances and the oxidative stress, through the development, validation and application of analytical methods for the determination of biomarkers of exposure and effect in urine and blood samples collected from occupationally and environmentally exposed subjects. One part of the project consisted of the study of different groups of general population, environmentally exposed to hazardous substances such as air pollutants (benzene, toluene and polycyclic aromatic hydrocarbons, PAHs) and phthalates in order to find a correlation between the concentration of their urinary metabolites and the oxidative stress biomarkers. A second part dealt with the study of groups of workers, occupationally exposed to different classes of dangerous substances, and/or to a physical risk agent, with the same purpose described above. This objective was achieved by (i) the development, validation and application of four targeted biomonitoring methods by HPLC/MS-MS for the analysis of exposure and effect biomarkers, (ii) the application of untargeted biomonitoring methods (1H-NMR) to samples of every group of subjects (thanks to the collaboration with the NMLab of Sapienza University) and finally (iii) the statistical analysis of the results from both types of methods (targeted and untargeted). Another important part of the PhD project concerned the experimental work conducted for a period of six months at the Laboratoires National de Santè (LNS) in Luxembourg, which led to the development of two new methods by HPLC/MS-MS for the analysis of (i) benzene and toluene urinary biomarkers and (ii) reduced and oxidized glutathione in whole blood, which will be applied to real samples in the future. The results show that targeted monitoring of biomarkers, such as oxidative stress biomarkers in the biological fluids of the exposed subjects, can be useful to evaluate the effects of the exposure to hazardous chemicals, opening new perspectives to the knowledge of the mechanisms of damage to health and to its prevention.