This review reports current knowledge regarding the roles that cadmium (Cd), mercury (Hg), arsenic (As), lead (PB), manganese (Mn), and zinc (Zn) play as endocrine-disrupting chemicals (EDCs). The influence of these metals on the endocrine system, possible mechanisms of action, and consequent health effects were correlated between experimental animals and humans. Analysis of the studies prompted us to identify some critical issues related to this area and showed the need for more rigorous and innovative studies. Consequently, it was recommended that future studies need to: (1) identify the mechanisms of action, because at the present time only a few have been elucidated—in this context, the possible presence of hormesis need to be determined, as currently this was reported only for exposure Cd and As; (2) study the possible additive, synergistic, or antagonistic effects on the endocrine system following exposure to a mixture of metals since there is a lack of these studies available, and in general or occupational environments, humans are simultaneously exposed to different classes of xenobiotics, including metals, but also to organic compounds that might also be EDCs; (3) assess the potential adverse effects on the endocrine system of low-level exposures to metals, as most of the information currently available on EDCs originates from studies in which exposure levels were particularly high; and (4) assess the effects on the endocrine and reproductive systems of other metals that are present in the general and occupational environment that have not yet been evaluated.

In recent years, nanoparticles have been increasingly used in several industrial, consumer and medical applications because of their unique physico-chemical properties. However, in vitro and in vivo studies have demonstrated that these properties are also closely associated with detrimental health effects. There is a serious lack of information on the potential nanoparticle hazard to human health, particularly on their possible toxic effects on the endocrine system. This topic is of primary importance since the disruption of endocrine functions is associated with severe adverse effects on human health. Consequently, in order to gather information on the hazardous effects of nanoparticles on endocrine organs, we reviewed the data available in the literature regarding the endocrine effects of in vitro and in vivo exposure to different types of nanoparticles. Our aim was to understand the potential endocrine disrupting risks posed by nanoparticles, to assess their underlying mechanisms of action and identify areas in which further investigation is needed in order to obtain a deeper understanding of the role of nanoparticles as endocrine disruptors. Current data support the notion that different types of nanoparticles are capable of altering the normal and physiological activity of the endocrine system. However, a critical evaluation of these findings suggests the need to interpret these results with caution since information on potential endocrine interactions and the toxicity of nanoparticles is quite limited.

The concept of hormesis, as an adaptive response of biological systems to moderate environmental challenges, has raised considerable nano-toxicological interests in view of the rapid pace of production and application of even more innovative nanomaterials and the expected increasing likelihood of environmental and human exposure to low-dose concentrations. Therefore, the aim of this review is to provide an update of the current knowledge concerning the biphasic dose–responses induced by nanoparticle exposure. The evidence presented confirmed and extended our previous findings, showing that hormesis is a generalized adaptive response which may be further generalized to nanoscale xenobiotic challenges. Nanoparticle physico-chemical properties emerged as possible features affecting biphasic relationships, although the molecular mechanisms underlining such influences remain to be fully understood, especially in experimental settings resembling long-term and low-dose realistic environmental exposure scenarios. Further investigation is necessary to achieve helpful information for a suitable assessment of nanomaterial risks at the low-dose range for both the ecosystem function and the human health.

Silicosis is a progressive fibrotic lung disease that is caused by the inhalation of respirable crystalline silica. Due to its high silica content, artificial stone (AS) can become a possible source of hazardous dust exposure for workers that are employed in the manufacturing, finishing, and installing of AS countertops. Therefore, the aim of this review was to verify the association between AS derived silica exposure and silicosis development, and also then define the pathological characteristics of the disease in relation to specific work practices and preventive and protective measures that were adopted in the workplace. A systematic review of articles available on Pubmed, Scopus, and Isi Web of Knowledge databases was performed. Although the characteristics of AS-associated silicosis were comparable to those that were reported for the disease in traditional silica exposure settings, some critical issues emerged concerning the general lack of suitable strategies for assessing/managing silica risks in these innovative occupational fields. Further research that is designed to assess the hazardous properties of AS dusts, levels of exposure in workplaces, and the effectiveness of protective equipment appears to be needed to increase awareness concerning AS risks and induce employers, employees, and all factory figures that are engaged in prevention to take action to define/adopt proper measures to protect the health of exposed workers.

Through a process of translocation across biological barriers, nanoparticles can reach and deposit in secondary target organs where they may induce adverse biological reactions. Therefore, a correct assessment of nanoparticle-induced adverse effects should take into account the different aspects of toxicokinetics and tissues that may be targeted by nanoparticles. For this reason, a comprehensive evaluation of renal nanotoxicity is urgently needed as kidneys are particularly susceptible to xenobiotics and renal excretion is an expected and possible elimination route of nanoparticles in living organisms. On one hand, summarizing the findings of in vitro and in vivo studies that have investigated the adverse effects of nanoparticles on the kidney, this review intends to provide a thorough insight into the nephrotoxicity of these substances. The evaluation of the in vitro studies revealed that different types of nanoparticles (carbon, metal and/or silica nanoparticles) are able to exert significant cytotoxic effects (i.e., decreased cell viability, induction of oxidative stress, mitochondrial or cytoskeleton dysfunction and cell membrane and DNA damage). On the other hand, in vivo studies demonstrated that nanoparticles exhibited an important nephrotoxic potential both at tubular (i.e., degeneration of tubular epithelial cell, cellular fragments and proteinaceous liquid in tubule lumen, renal interstitial fibrosis) and glomerular level (i.e., swollen glomeruli, changes in Bowman’s space and proliferation of mesangial cells). Although the data currently available indicate that nanoparticles may adversely impact the renal system, further studies are needed in order to clarify all the potential molecular mechanisms of nephrotoxicity induced by these xenobiotics, in particular at glomerular level.

Particular working conditions and/or organization of working time may cause important sleep disturbances that have been proposed to be predictive of cognitive decline. In this regard, circadian rhythm misalignment induced by exposure to night work or long working hours would be responsible for cognitive impairment. Nevertheless, evidence supporting this correlation is limited and several issues still need to be elucidated. In this regard, we conducted a systematic review to evaluate the association between shift/night work and cognitive impairment and address its main determinants. Information provided by the reviewed studies suggested that night work might have serious immediate negative effects especially on cognitive domains related to attention, memory and response inhibition. Furthermore, cognitive performance would progressively worsen over consecutive night shifts or following exposure to very long work shifts. Otherwise, conflicting results emerged regarding the possible etiological role that night work chronic exposure would have on cognitive impairment. Therefore, circadian rhythm desynchronization, lack of sleep and fatigue resulting from night work may negatively impact worker’s cognitive efficiency. However, in light of the considerable methodological variability of the reviewed studies, we proposed to develop a standardized research and evaluation strategy in order to obtain a better and comprehensive understanding of this topic.