Elena Sturchio

Microplastics (MPs) are now ubiquitous environmental contaminants that lead to unavoidable human exposure; they have received increasing attention in recent years and have become an emerging area of research. The greatest concern is the negative impacts of MPs on marine, fresh-water, and terrestrial ecosystems, as well as human health, to the extent that the World Health Organization (WHO) calls for increased research and standardized methods to assess exposure to MPs. Many countries and international organizations are implementing or proposing legislation in this regard. This review aims to summarize the current state of legislation, indoor and outdoor contamination, and potential human health risk due to exposure to airborne MPs, considering that occupational exposure to MPs is also becoming a growing area of concern. Even though research regarding MPs has continuously increased in the last twenty years, the effects of MPs on human health have been scarcely investigated, and toxicity studies are still limited and not directly comparable, due to the lack of standardized studies in this field.

Malignant mesothelioma is an aggressive tumor resistant to current therapies with a latency period ranging between 20 and 60 years, caused by inhalation of asbestos fibers, that continues to represent a social and healthcare issue. The high percentage of people exposed to asbestos for professional or environmental reasons is associated with the high biopersistence of its fibers and with its widespread use in the last century. Approximately 20-40% of men report an occupational history that might have caused the workplace exposure (criteria Helsinki, 1997). Some authors are evaluating the possible use of bioindicators as a screening and early diagnosis tool. In this regard, the use of microRNAs has been proposed as powerful diagnostic and prognostic biomarkers for many tumors and human diseases. This review focuses on the current state of knowledge on the key role of microRNAs expression as new malignant mesothelioma biomarkers, in early clinical diagnostic applications.

We present a computer assisted method for the examination of the structural changes present in the probe organism Vicia faba exposed to inorganic arsenic, detected by means of Fourier transform infrared (FTIR) and Fourier transform near infrared (FTNIR) spectroscopy. Like the common ecotoxicological tests, the method is based on the comparison among control and exposed sample spectra of the organisms to detect structural changes caused by pollutants. Using FTIR spectroscopy, we measured and plotted the spectral changes related to the unsaturated to saturated lipid ratio changes (USL), the lipid to protein ratio changes (LPR), fatty and ester fatty acid content changes (FA), protein oxidation (PO) and denaturation, and DNA and RNA changes (DNA-RNA). Using FTNIR spectroscopy, we measured two spectral ranges that belonged to hydrogen bond interactions and aliphatic lipid chains called IntHCONH and Met1overt, respectively. The FTIR results showed that As modified the DNA-RNA ratio and also caused partial protein denaturation in the Vicia faba samples. The FTNIR results supported the FTIR results. The main advantage of the proposed computational method is that it does not require a skilled infrared or near infrared operator, lending support to conventional studies performed by toxicological testing.

Over the last few years, there has been an increased interest in exploiting allelopathy in organic agriculture. The aim of this investigation was to examine the effects of essential oil mixtures in order to establish their allelopathic use in agriculture. Two mixtures of essential oils consisting respectively of tea tree oil (TTO) and clove plus rosemary (C + R) oils were tested. Phytotoxicity and genotoxicity tests on the root meristems of Vicia faba minor were performed. A phytotoxic influence was particularly relevant for C + R mixture, while genotoxicity tests revealed significant results with both C + R oil mixture and TTO. Phenotypic analysis on Vicia faba minor primary roots following C + R oil mixture treatment resulted in callose production, an early symptom attributed to lipid peroxidation. The approach described in this study, based on genotoxicity bioassays, might identify specific DNA damage induced by essential oil treatments. These tests may represent a powerful method to evaluate potential adverse effects of different mixtures of essential oils that might be useful in alternative agriculture. Future studies are focusing on the positive synergism of more complex mixtures of essential oils in order to reduce concentrations of potentially toxic components while at the same time maintaining efficacy in antimicrobial and antifungal management.

Exposure to asbestos is the predominant cause of pleural mesothelioma (PM). The PM is a tumor difficult to diagnose, chemoresistant, and with rising Incidence. The long latency periods and the lack of preventive and therapeutic strategies for the MP, suggest that asbestos will be a social and health issue in the near future. Therefore, this overview focuses on current knowledge of epigenetic alterations and on the key role of microRNAs, small RNAs that negatively regulate gene expression, as biomarkers in PM development. Dysregulated microRNA expression pattern is specific for different cancers, including MP. MicroRNA expression analysis is a promising tool for diagnosis, typing of MP than normal tissue and other lung tumors and monitoring of new therapies. However, a better knowledge of miRNA signatures in PM is still necessary to verify the contribution of specific miRNAs as diagnostic biomarkers, also compared to different asbestos forms, exposure and subject work history.

The inorganic Arsenic (iAs) is a metalloid widely diffuse in all environmental matrices. The iAs has been classified as a Group 1 carcinogen by the International Agency for Research on Cancer. The microRNAs (miRNAs) are small non coding RNAs that negatively regulate the expression of hundreds of target genes in many key physiological and pathological cell processes, including stress response, differentiation, proliferation, apoptosis and cancer, miRNA expression profiles appear altered in most human cancers and it has been highlighted the potential of miRNA profiling in cancer diagnosis and prognosis. The present study evaluates the effect of iAs exposure on global miRNA expression in Jurkat cells. Treated cells show a reproducible increase in the expression levels of three miRNAs: miR-663, miR-222 and miR-638. This study supports the importance to proceeding in the investigation aimed to the possible application of some miRNAs as biomarkers in the environmental and occupational exposure to iAs.

Exposure to inorganic arsenic (iAs) through drinking water is a major public health concern affecting most countries. Epidemiologic studies showed a significant association between consumption of iAs through drinking water and different types of cancer. However, the exact mechanisms underlying As-induced cancer and other diseases are not yet well understood. The aim of this study is to determine the effects of exposure iAs (20 or 30 mg/L) on Vicia faba seedlings in terms of phytotoxicity, genotoxicity, and spectroscopy by investigation of molecular modifications using infrared (FTIR) and near infrared (FTNIR) spectroscopy. Further, the mitigation effects of a precursor of glutathione (GSH), N-acetylcysteine (NAC), were also assessed. Spectroscopic and genotoxicity analysis demonstrated that specific molecular changes were directly correlated with iAs exposure. Comet assay in Vicia faba showed significant effects at concentrations of 20 and 30 mg/L, depending on the structural changes involving nucleic acids as identified by FTIR and FTNIR spectroscopy. Results of phytotoxicity and micronuclei tests were significant only at higher iAs concentrations (30 mg/L), where an antioxidant effect of NAC was noted. The two spectroscopic techniques demonstrated molecular modifications predominantly associated with chemical interactions of iAs with biomolecules such as nucleic acids, carbohydrates, lipids, and proteins in Vicia faba. Our findings suggest that further studies are required to better understand the mechanisms underlying toxicity produced by different As chemical forms in vegetal and agricultural species.