Trace elements produce double-edged effects on the lives of animals and particularly of humans. On one hand, these elements represent potentially toxic agents; on the other hand, they are essentially needed to support growth and development and confer protection against disease. Certain trace elements and metals are particularly involved in humoral and cellular immune responses, playing the roles of cofactors for essential enzymes and antioxidant molecules. The amount taken up and the accumulation in human tissues decisively control whether the exerted effects are toxic or beneficial. For these reasons, there is an urgent need to re-consider, harmonize and update current legislative regulations regarding the concentrations of trace elements in food and in drinking water. This review aims to provide information on the interrelation of certain trace elements with risk of autoimmune disease, with a particular focus on type 1 diabetes and multiple sclerosis. In addition, an overview of the current regulations and regulatory gaps is provided in order to highlight the importance of this issue for everyday nutrition and human health.

In order to understand the distribution of fluorine in surface environments, also linked to fluoride deposits, this paper discusses the role of rift systems in fluorine enrichment of surface waters, with two examples: the Sardinia Island and the East African Rift. The main goal of this study is aimed to highlighting the areas that could potentially host fluorine in the surface waters in order to make it easier the lecture also for people to search and read not experts in the field, such as the biomedical field. Furthermore, potentialities and limitations of the currently available defluoridation techniques were examined, in order to identify the best intervention technology. From a careful review of the literature, to the addition of the extensive field observations in Sardinia and Ethiopia carried by the authors in the previous decades, we highlight the origin, processes and evolution of F-migration in Rift systems. The given examples of Sardinia and Ethiopia show that the origin and consequent behaviour of fluorine is strictly controlled by the rift systems. In this framework, the availability of fluorine for surface waters depends on two possible types of sources: a direct supply and an indirect supply. Directly from spring waters and ground waters fed by hydrothermal systems related to rifting, and indirectly from the leaching of products of rift-related activities, such as fluorite-bearing deposits, sedimentary or meta-sedimentary rift-related sequences, and volcanic or metavolcanic complexes emplaced along rift structures. The whole geological history of a given area must be taken into account in interpreting its present fluorine geochemistry. In conclusion, we underline the aspects of a possible control of these areas where fluoride exposure might lead to a long-term harm to local communities and we point out the nowadays best remediation-technologies, discussing their pro and cons in their applicability to different scales and social-contexts.

It is well known that genetic and environmental factors jointly influence the risk of developing human diseases. The interplay between genes and the environment is mediated by epigenetic changes of the genome consisting in modifications of DNA (e.g., by methylation) or of proteins that intimately associate with DNA, without altering the underlying DNA sequence. One of the main focuses of epigenetic research is the study of cancer, that traditionally was viewed as a genetic disease but it is now clear that its onset is preceded by epigenetic abnormalities while the genetic modifications occur later. The study of epigenetic alterations has also a particular relevance in understanding the effect of occupational exposures to pollutants and new materials, such as titanium dioxide (TiO2) nanoparticles (NPs) and nanofibers (NF), which are promising candidates for numerous applications in consumer products, but with potential toxic effects.The aim of this project is to investigate whether TiO2 represents a risk to human health.To this purpose, we have chosen to investigate the possible presence of circulating DNA in the plasma showing methylation alterations identified by our research group as tumor biomarkers, in subjects exposed to TiO2, compared to the plasma of cancer patients. We enrolled 40 workers employed in TiO2 production, 5 office workers, 18 external controls and 19 patients affected by colorectal cancer. Circulating DNA was extracted from the plasma of each subject, then converted by sodium bisulfite to interrogate the methylation levels of a particularly informative tumor biomarker using the qPCR technique called MethyLight. Preliminary results show, as expected, high methylation levels in cancer patients, low or negligible levels in control subjects and, quite surprisingly, intermediate levels in exposed subjects, with values very similar to those of cancer patients for some categories of workers. More in-depth multivariate analyses, taking into account possible confounding factors such as smoking habits, diet, comorbidities, will be conducted, as well as extending the series as much as possible.These results, although preliminary, seem to confirm a potential risk conferred by TiO2 exposure on human health. To date, the European Food Safety Authority has stated that a potential genotoxicity of titanium dioxide as a food additive (E171) cannot be excluded. However, its use in cosmetics and medicines has not yet been banned.