Professor Claudia Petrarca has carried out toxicological studies on the carcinogenic, genotoxic, and immunotoxic actions of known and emerging environmental and/or occupational xenobiotics. She has particularly made contributions to highlighting the different biological effects of heavy metals as well as crocidolite asbestos in relation to chemical speciation, nano-/micro-size particles, and aggregation/agglomeration status. She also studies immune systems/cells/cytokine outcomes upon exposure/treatment and the definitions of nuclear damage, biodistribution, and cytokine networks. This part of her research has contributed to the understanding of the mechanisms underlying the cyto-immunotoxicity of heavy metals, in the form of ions, microparticles, and nanoparticles, and of asbestos. Currently, her research activities are devoted to the identification of early biomarkers of asbestos exposure for risk assessment and the timely detection of asbestos-related pathologies. Furthermore, she is conducting studies based on T regulatory cells and microRNA analyses in search of nutrients/phytochemicals/functional foods with a translational value as conditioning/tolerance-promoting agents.